cc  >> Nadia Dominguez: Hi and  welcome to Wednesday Nite  at the Lab, at the UW-Madison  Biotech Center.  Tonight, we welcome Dr. Phil  Simon, of the Department of  Horticulture at the University  of Wisconsin-Madison.  In addition to being a professor  of horticulture, Dr. Simon is  research geneticist for the USDA  and ARS, the Agriculture  Research Service.  His research focus of his nine  current projects is on carrot  and garlic genetics and breeding  to improve the crop for growers  and consumers, collection and  utilization of germ plasm and  development of genomic tools for  these crops.  His extensive research has  produced well over a hundred  journal articles.  Dr. Simon also oversees the USDA  carrot improvement program which  provides new carrot breeding  stocks for carrot breeders  globally.  He has been on several germ  plasm collection expeditions in  central Asia, North Africa and  Europe to collect wild and  cultivated carrots.  His carrot research examines  genes that control the orange,  red, yellow, white and purple  colors of carrots.  So please join me in welcoming  Dr. Phil Simon to Wednesday Nite  at the Lab.  [APPLAUSE]  >> Phil Simon: Thank you, Nadia. 

 I appreciate that generous  introduction, and I'm very glad  to be able to be here and speak  to you tonight.  I'll try to speak loud in hopes  that everybody will hear me,  and my main topic that I'll be  coming back to several times  during the evening is the topic  of carrots because, as Nadia  indicated, I've spent quite a  bit of time doing research on  carrots.  But I'm going to talk about  carrots from the context,  initially, of agricultural  development and really the  development of human  civilizations.  Because to a fairly great  extent, the historical  development of crops and  agriculture can give us some  insights, not only on how those  crops were domesticated, but,  in some cases, give us some  insights on some modern uses of  crops.  And I will refer to carrots in  this portion of the talk, and  then I'm going to switch gears  and focus primarily on some  nutritional compounds in  carrots, the carotenes, and some  of the relationships that plants  and humans have, in this case,  in our diets and again talk some  more about carrots.  So first talking about this  interaction of plants and  people.  This whole process of humans  interacting with their  environment has been underway  for a long time.  This is a picture taken in  central Asia about 20 years ago.  But it could have been taken,  except for the clothing of the  shepherd, it could have been  taken anytime within the last  tens of thousands of years when  individuals have been  domesticating animals, in this  case sheep, and moving their  flocks and herds around as a way  to maintain a food supply.  And, obviously, the need to eat  is an important one for humans,  and before we had the  development of agricultural,  individuals were dependent on  hunting and, to some extent,  herding animals. 

 And it's estimated this whole  process by which people were  able to keep themselves fed  before the well-established  development of agricultural was  relatively inefficient in terms  of land.  It's been estimated about 25  square miles necessary to  sustain one adult in this  hunting and herding type of an  agricultural or pre-agricultural  system.  The time to get things done, as  it were, in this lifestyle of  hunting and herding was one that  really was time-dependent.  Now, as a farmer today, this is  also a big full time job.  But before the establishment of  farms as we know them, in  addition to being very time  dependent, it was a difficult  type of a life from the  standpoint of things like taking  care of the infirm.  It you were ill or a member of  your family was ill and it was  necessary for you to move ahead  to, say, hunt or to move your  flocks forward to feed them, in  a lot of cases those infirm that  weren't able to move very  readily had to be left behind.  So it was a pretty miserable  healthcare system in this year  when there was this constant  need to keep moving.  And there was relatively little  free time.  There certainly was some good  evidences of the development of  art and a little bit of the  development of language before  civilizations really settled  down but it was pretty  difficult.  And Thomas Hobbes described this  type of a life as being nasty,  brutish and short. 

 It may not be quite that bad but  there certainly are some pretty  difficult times if you're  dependent on moving your herd or  hunting as your source of food.  But about 10,000 or 12,000 years  ago agricultural began.  And it began in the form of  villages, and these were  somewhat mobile structures, or  groups of structures initially,  but eventually game permanent  and the thing that we now call  social order became more  well-developed at that time.  Another thing that came along  with the settling down of  individuals in this process of  civilization development is one  that is a much more efficient  use of land in the sense that  only approximately a tenth of a  square kilometer is necessary to  sustain an adult with modern  agricultural practices.  So it's a much more concentrated  use of land.  And with this process of  civilization we have the benefit  of additional time on our hands.  With civilization, individuals  have more time to think and as a  consequence as civilizations  developed, inventions, language,  developed as well.  So with the development of  stable food supplies and we see  on major changes in humankind.  The first civilization was one  in the so-called Fertile  Crescent which is in the upper  right-hand portion of this  diagram which is in southeastern  Turkey, Sierra, Iraq, Iran and  Lebanon and Israel today.  This happened about 10,000 to  12,000 years ago. 

 And this process was also begun  a little more recently in a  couple of other places, in  particular north China and also  in Peru and in Mexico a little  more recently, like I said,  about 7,000 years ago.  The places where these first  agricultural villages and  societies and civilizations were  developed depended on available  water and also the availability  of edible plants.  And those plants varied from  place to place.  In the Fertile Crescent it was  primarily wheat and barely, and  animals were sheep.  But I think Jacob Bronowski, who  some of you may recall had a  series on TV called Ascent of  Man on public television a  number of years ago, and in this  book had the statement that I  thought was appropriate that  first humans domesticated crops  and then crops domesticated  humans in the form of  civilizations developing.  So this whole process by which  we have developed agriculture,  which is heavily dependent on  crops and domesticated animals,  is one that is very central to  the development of  civilizations.  Now, crops initially, sensibly  were domesticated as a source of  nutrients.  People were looking for stable  food supplies.  But as a byproduct of having  something so valuable as a crop  in hand, wheat in some storage,  food plants have also become  used very widely as a source of  trade and a source of wealth  throughout history.  So we really have these  different, really, uses of food. 

 One is to feed us and along the  way some people are earning a  living from crops.  Along the way, also, crops  change from their wild  progenitors.  So the crops that we have today  all came from wild plants, the  first wheats from which wheat  was eventually domesticated  looks like that in the upper  portion of this picture.  And then the early cultivated  wheat, kernels were much larger.  These are from sites in the  Fertile Crescent.  We go to sites in the Americas,  we find evidence of the  domestication of corn, where the  first corn that was used in  early civilizations had a very  small ear.  You don't see the kernels here,  they're gone, but you still see  the cob.  And as corn evolved, much larger  ears came with that.  And these types of changes are  common in the domestication of  pretty much all crop plants.  And with this domestication  process we see the first crops  domesticated were what we refer  to today as staple food crops. 

 These are crops that are very  good sources of energy, of  carbohydrates in particular.  And, hence, they're used as  staple foods.  In the Asian first  civilizations, rice was that  first domesticated crops and in  the Fertile Crescent was wheat  and corn in the Americas and  also, to some extent, a little  bit later potatoes were  domesticated.  And these became the major  sources for calories in humans  in these early civilizations.  And not only humans but, in many  cases, they started feeding  their domesticated animals with  these staple food crops as well.  So again this whole process of  crop domestication is very  central to the development of  human civilizations.  Now along the way, as well, not  only were these staple food  crops developed but also these  fruits and vegetables that in no  case, or at least in very rare  cases, are staple foods.  But these are also foods that  were regarded as being valuable  in the diet from the standpoint  of providing additional flavor  and color to diets.  Today we know, in fact, that  these fruits and vegetables that  were domesticated thousands of  years ago, in some cases, in  addition to providing some color  and flavor to diets, also  provide some essential  nutrients.  This was first realized, from  what we can tell in history,  with the understanding that the  disease scurvy was, to a fair  extent, eliminated by the use of  citrus crops. 

 Actually before that in about  the 1500s, someone boiled pine  needles and found that they  could eliminate scurvy.  This was not quite so well  established but certainly in the  1700s it was understood that  citrus fruits could eliminate  scurvy.  It wasn't known exactly what was  in citrus fruits to do this, but  there was some understanding  that food provides something  besides the calories that were  so sought after throughout all  of civilization.  And it wasn't really until the  20th century that the whole  science of nutrition developed.  And with this it became clear  that humans really are very  dependent on a wide range of  crops besides these staple food  crops for things like vitamins  and minerals.  And one premier example that  I'll mention since we're here at  Wisconsin is the discovery of  vitamin A at the University of  Wisconsin in 1913.  It's called vitamin A because it  was the first vitamin and the  others soon followed.  So, again, while staple food  crops have been long appreciated  as a source of essential  nutrients in the diet, it's much  more recently that fruits and  vegetables are known to take on  this type of a role.  This is kind of a complicated  table but I present it because  it gives you some overview of  what some of the nutrients we  have in fruits and vegetables  and cereals are.  I don't have things like legumes  on this table so it's not  complete nor is it complete for  all the nutrients but just some  examples. 

 So if we look at this table, at  some example of some nutrients  in the US diet, and this is now  relatively recently, we find  that if we look at plants in  general, all of the plants that  provide food in our diets, the  great majority, well over 50%,  of the carbohydrates is provided  from all those plants, most of  it comes from cereals.  So when I've got four asterisks,  that means more than 50%, in  this case it's well over 90%.  Three asterisks is over 40% of  the carbohydrates in the US diet  today comes from cereals.  Proteins, a substantial amount  does comes from cereals.  Again, I don't have legumes,  they provide proteins as well.  But the balance beyond what's in  this column for plants would be  coming from foods derived from  animals and so that these  numbers will not, in most cases,  add up to a hundred except for a  rare few.  And we do get over 20% of the  fats in our diet from those  crops that are listed here.  A lot of the vegetable oils also  contribute to fats in the diet.  So these are really some of the  major what are called  macronutrients, or large volume  nutrients, that we eat on a  regular basis.  But in addition to that we have  micronutrients and minerals. 

 And included in those are the  vitamins and a few minerals that  I have listed here.  And you can see that, number  one, a very significant portion  of vitamins and minerals come  from plants, and another  interesting point of this part  of this table is that vegetables  and potatoes and fruits are  major contributors of things  like vitamin A, vitamin C, we  mentioned that example from  scurvy before.  Notice in fact that vegetables  provide more vitamin C in the  diet than fruits.  Potassium and vitamin B6, a  substantial amount from  vegetables and potatoes, over  20%.  Copper and folates, over 20%  from potatoes as well as 20 plus  percent from cereals.  And iron, a couple of B  vitamins, from plants, in  particular from cereals in the  diet.  And, of course, fiber is  well-known as coming from plant  sources and very important for  the diet.  Not really necessarily defined  as a nutrient but still a very  important part of the foods that  we eat from the standpoint of  sustaining human health.  So the point of this chart is to  point out that, yes, the staple  foods do in fact provide major  sources of calories but a lot of  other nutrients and  micronutrients, in particular,  come from fruits and vegetables.  They contribute significant to  human health and I think  everybody here knows that. 

 But again this wasn't really  very well known at all even a  hundred years ago.  I'm going to switch gears then  and move from more talking in  general about plants to focusing  more on things like carotenes  and carrots, and in that light  I'm going to spend some time  talk approximate vitamin A which  is this is just that same table  as it was in the last slide.  Note that over 40% of the  vitamin A in the US diet comes  from plant sources.  And, in particular, vegetables  and potatoes.  And vegetables, in this case,  are a major source of vitamin A  in the diet.  And I'm going to talk about  vitamin A as a focus mainly  because I work on carrots and  it's a source of vitamin A.  So, again, just to reiterate  some of the topical areas I'm  considering, this question of  domestication of plants does  give us some insights into how  we use them and what they might  be good for and we can direct  this type of questioning to  carrots and really ask the  question of what can we learn  from the historical development  of carrots in agriculture.  So to sort of recapitulate this  longer story that we have in  things like wheat and rice,  let's take a look at the origins  of carrots.  First of all, take note that  carrot is really a domesticated  form of Queen Anne's Lace and I  know everybody in this audience,  unless you came in today from  points far from here and never  have been in Wisconsin before,  know what Queen Anne's Lace is.  It occurs along the roadside or,  in this case, vacant lots. 

 This is a photograph from a  vacant lot in Middleton a few  years ago.  And you see the prominent --,  the big white set of flowers,  and I'll show you some other  pictures of that.  It's a weedy plant all over the  world.  This is a scene, maybe you can't  see so well, but it's similar to  this one but much more mature  crop.  This is one photo I took in  Tunisia, actually was in my trip  earlier or is last year.  This is a vacant lot in a  village in Tunisia, and it's  just become completely covered  with wild carrot.  So it's really the same version  as this picture of Middleton,  but it's a little later in the  season and halfway around the  world.  And these are some wild carrots  that were collected initially  from France.  And typical for this plant you  see a white, very fibrous type  of root and often plants that  are flowering, which you won't  typically find in your carrots  in your garden.  Now the historical development  of carrot is a lot shorter than  that of things like wheat and  rice and potatoes. 

 It's only been domesticated for  sure about 1100 years ago.  And it was thought that the  carrot was first domesticated or  was first cultivated in  Afghanistan.  And a thousand years is  relatively recent from this  whole scale of domestication,  like I said, compared to the  long history that crops like  wheat have.  There is some evidence that  carrot may have been known and  grown in the Roman empire.  The words are a little bit  difficult.  There's a word, Pastinaca, that  is a scientific name for  parsnip.  And it's not clear whether  parsnip or carrot was grown in  the Roman empire.  It was never was particularly  well described.  It was fairly well described in  central Asia and Afghanistan.  So we don't know a lot about  whether carrots occurred in the  Roman empire and, if they do,  what they looked like or tasted  like. 

 But the carrots of Afghanistan  1100 years ago were different  from today's carrots.  They weren't orange like today's  carrots, but rather they were  yellow or purple.  And I've got heaps of carrots up  in front here.  And orange carrots were not even  known in this era.  Based on historical writings,  and, to some extent, artwork,  it's pretty clear then that  carrots spread to the west  initially, westward from central  Asia to the Middle East and then  North Africa and then eventually  Europe.  And a little bit later it spread  eastwardly to India and China.  It's only around the 1600s,  maybe the 1500s or 1400s, that  orange carrots were first noted.  So orange carrots may have been  the food fad of the 1500s.  We don't really know why orange  carrots were developed.  But either in northern Europe or  Turkey, and some debate as to  where orange carrots originated. 

 And it was in the 1950s that the  first hybrid carrots, which are  your typical carrots you get in  the grocery store today, began.  So there's a big jump here but  we'll talk more about the older  period.  So some yellow carrots and  purple carrots on the bottom  now.  This is a purple carrot with an  orange core that I have in this  photograph.  The purple carrots of this early  era would have been purple with  a yellow core.  And this is a red carrot, which  is a pigment I won't talk much  about, and then your typical  orange carrots.  So a very brief history on  carrots and a little bit about,  again, the spread of carrots  from Afghanistan, Iran, Iraq and  that vicinity in pre-900 AD,  purple and yellow colors, to  Iran in 900.  Sierra, North Africa, 1000;  Spain, 1100, as it jumped across  the Mediterranean and spread in  the Mediterranean into Italy by  the 1300s and first noted in  Asia in the 1300s and China.  And spread further north in  Europe and to northern Europe  and eventually to England by the  1400s, and in the eastward side  spread to Japan from China in  about 1600, relatively recently,  only 400 years.  So by the 1600s in all of Europe  and then the Americas started  having carrots and by that year  then the typical colors for  carrots changed from purple and  yellow to orange and white. 

 And in the 1700s orange carrots  were first noted in Japan and  the first carrots were named,  and I'm not going to go into  naming carrots, but carrots,  like other crops, do have  different names for varieties,  were first named around the  1700s in northern Europe.  This is a drawing, more than a  drawing, it's artwork from Italy  from the 1500s and so it looks  like this individual is growing  carrots that long ago.  So we do have, really, some  evidence of carrots following a  domestication path somewhat  parallel to things like wheat  and corn in that we go, in the  case of wheat, from a  small-grained or in the case of  corn a small-cobbed fruited  plant to, in carrots, going from  this wild rooted type of wild  carrot, and this is actually a  cross between a wild carrot and  a domesticated carrot and so  when you intercross this nice  orange carrot with a wild  carrot, the hybrids look about  like a wild carrot.  So if you want to grow carrot  seed in your garden, make sure  you don't have any wild carrots  around and good luck if you can  do that.  But the point though that I want  to make is that we've come a  long ways in this process of  domesticating carrots in the  last thousand years from this  wheaty form, which some brave  souls ate probably in some  pretty dire hunger about  1000-1100 years ago, to the  modern forms.  And I would mention, you can eat  the roots of Queen Anne's Lace.  Make sure you eat them before  they start flowering.  Once they start flowering they  get very woody.  You won't become ill from them  unless you already have a carrot  allergy which is pretty rare.  So it is possible to eat Queen  Anne's Lace, but I would  recommend carrots you get in the  grocery store or you grow in  your garden as a better  alternative. 

 So carrots did go through this  domestication process, and, like  most domesticated plants and  animals, there's a wide range of  diversity in the domesticated  crop.  What we see in grocery stores  today for virtually all crops is  a pretty narrow subset of what's  out there more broadly.  This is actually a carrot that's  a hybrid between a wild carrot  and a domestic one.  There are white carrots and I've  got one here.  And these white carrots were  apparently grown as a fodder  crop to feed animals.  And a lot of times the whole  crown of the carrot will stick  up above the ground, and they  tend to be very large rooted.  So carrot, historically, has had  a broader use than it currently  has.  I'm not aware of any fodder use  or very limited fodder use of  carrots in the world.  But some of these unusual shapes  are grown elsewhere in the  world, although typically we  grow long, thin carrots in the  US.  Most of the rest of the world  grows a shorter, kind of a blunt  carrot, than they do. 

 But typically not this range of  shape or color carrots grown but  these are historical facts.  One point I'll also make about  carrots is that one of the major  studies trying to understand the  history of carrots and it's  domestication was a study that  we all should aspire to design  for ourselves.  And this was a study that a  Dutch researcher named Bonga had  underway for a long time.  And his approach to  understanding the history of  carrots was to go to all the  major art institutes, like the  Louvre, in Europe and look at  the color of carrots through  history.  And bearing in mind that these  colors change as the pigments  used varied over time.  But he was able to get some idea  of this.  And that's really some of the  best evidence of where orange  carrots came from and when they  arrived.  In pictures like this one of a  boy holding a carrot in the  1700s where this carrot is in  fact orange.  So I'm going to talk mainly  about carrots and nutrition but  there's often some general  questions about carrots and I  just wanted to clear those up  before we move along.  Some of them I've already  addressed. 

 One is the carrot is the same  plant, it's the same species as  Queen Anne's Lace.  And it's so named because the  carrot umbel, this prominent  collection of flowers in groups  on a carrot plant, often, in the  wild in particular but some  domesticated forms as well, have  a purple flower in the middle.  And the story goes that this  name Queen Anne's Lace came  about because Queen Anne is  reputedly to have pricked her  finger while adding a round,  laced napkin and bled on it,  where upon the similarity of the  stained napkin to wild carrot  umbels was noted.  In fact, it's not blood, it's  probably an attractant to  insects.  Flies go to where other flies  are so carrot has somehow  figured out that looking like a  fly will attract flies to it.  The first carrots were purple  and yellow, I mentioned that  already.  Peeled carrots or baby carrots  that come in bags like this,  are, in fact, pieces of other  carrots cut up.  And here you see some longer  carrots, and they're just cut in  pieces and peeled.  Consuming large amounts of  carrots can give your skin an  orange color, but it will not  give you vitamin A toxicity.  Carrots provide vitamin A and if  you eat too much vitamin A as  vitamin A, you can get some  toxicity from it. 

 If you eat too much carrot, you  don't get vitamin A poisoning  but what can happen is your skin  can turn orange.  And in fact Gerber and Heinz get  reports of this every year of  parents who are concerned by  their kids who are eating a lot  of orange baby food and  wondering why their kids are  turning orange.  It's not going to hurt you, in  fact it will protect you from  the sun.  It's a great sun block but you  have to put up with looking  orange along the way.  The carrot pigments, in fact, do  improve your eyes.  They won't improve myopia or  farsightedness or astigmatism  but they will help prevent night  blindness and the yellow  pigments will help prevent  against macular degeneration.  And commercial carrots in the  store today are hybrids.  And that hybridity, and I won't  go into this anymore at all, is  based on the mitochondria genome  of wild carrots.  So every carrot that you get in  the grocery store has genes from  wild carrot in it because that's  the basis for making hybrid  seed.  That's a whole other lecture so  I won't go into that, but to me  it's an interesting fact. 

 Yes?  >> So what about how those  things are preserved, carrots in  the small bags, the small  carrots?  >> They're peeled and in some  cases they will dip them into a  solution, sometimes it's a  vitamin C solution and in some  cases they've got a few other  innocuous chemicals that they  use on food but more often than  not there's no preservative at  all.  It just turns out carrots  preserve themselves pretty well.  And now there's yellow ones too.  So just some carrot facts  because, like I say, when you  talk about carrots some of these  miscellaneous things come up.  But now going back to my theme  of carrots as a source of  nutrients for consumers, in fact  carrots are a source of income  for growers.  And so with projects like mine  we look at this question what  can we do for growers and what  can we do for consumers.  For growers they're interested  in nice uniform carrots.  They'd like every one to be the  same size, and that's, in fact,  what the impetus for developing  hybrid carrots is because they  tend to be much more uniform.  Growers would also like to have  carrots free from defects.  These are some carrots attacked  with nematodes. 

 And if you have nematodes in the  ground, these are not the  nematodes that attack us, they  attack a lot of other plants but  not us.  Nematodes in the ground give us  these root knots, and so we work  a lot on disease resistance like  this because it translates to  the growers saving a lot of  pesticides and money and also  saves us from exposure to these  compounds in the environment.  On the consumer side, another  thing we do is look at flavor  because flavor is very important  to people that eat carrots, and,  in particular, almost everybody  says they wish they had sweeter  carrots.  And we can take a poll later.  And they prefer carrots that are  not harsh or turpentining,  sometimes referred to as bitter.  Generally, people are looking  for a uniform orange color and  convenience and that's really  what the big impetus for baby  carrots is.  You're paying about three times  as much per unit weight for  these carrots as you are for  whole carrots.  Didn't cost the growers that  much to make these so you're  paying for that convenience.  At the same time, consumers are  much more willing to share their  opinions on flavor and quality.  And so it's really shaped up the  industry so they are growing a  better product than they did 20  years ago before baby carrots  were developed. 

 And consumers are very  interested in nutritional  quality but not as a first order  of interest.  Flavor is much more important  and convenience.  We're all interested in  nutrition.  So we work on nutrition in my  project because it's good for us  and because we can.  We have a lot of latitude to  improve carrots for nutrition so  we do it.  And so I'm going to change gears  a little bit now and start  talking about carrots and  carotenes.  Carotenes are pigments that  occur in all green leaves of  plants.  And they occur there because  they're essential for  photosynthesis.  And you can say, I didn't tell  you yet but I think you know,  carotenes are orange, why can't  you see them?  It's because the green pigments,  the chlorophylls, mask the  yellow pigments and orange  pigments.  When leaves, quote, turn orange  or yellow in the fall sometimes  that's because the chlorophyll  is degrading and what's left is  the carotenes and so those  carotenes were there all the  while, you're just starting to  see them. 

 Some cases they actually  accumulate then.  But the essential role for  carotenes in plants, or one of  the two, is to protect the green  pigments in plants in  photosynthesis from some of the  oxidation reactions and other  devastating chemicals that come  about in this whole  photosynthetic process.  It creates some nasty  byproducts, and carotenes are  there to protect the leaves of  plants from these byproducts.  There are mutants of tomato, for  instance, that have no carotenes  in the leaves, those leaves are  white when the plants are  exposed to the sun.  Because the photosynthesis  process not only, there is no  carotene to protect the  chlorophyll and the chlorophyll  is broken down without the  carotenes that are protected.  So that's the first prime use of  carotenes, but another aspect of  carotenes that's important for  plants is that they're attracted  to herbivores.  And here's some examples of  peppers and tomatoes where  herbivores, animals that eat  fruits in this case, are  attracted by these colors.  Carotenes, in fact, are a large  group of chemicals, and I'll  show you some chemical  structures in a minute if you're  really interested in that, and  I'm sure you are, is about 600  yellow, orange and red pigments  that are in this carotene or  carotenoid family.  Only a few of these compounds  are precursors to vitamin A.  I'll talk quite a bit more about  vitamin A and I'll show you how  that happens but a very small  subset of these 600 when we  consume them, or other animals  consume them, are broken down  into vitamin A. 

 So these are referred to  as provitamin A carotenes  because they are precursors  to vitamin A.  And, in fact, all vitamin A in  animals comes from carotene.  We know all cows eat grass.  When they eat that grass, the  carotene in the leaves is  converted to vitamin A.  So when we eat meat or drink  milk, the vitamin A that we get  is coming from the break down of  the carotenes in those animals.  Animals cannot by themselves  create vitamin A.  It's always a break down product  of vitamin A.  Sometimes when we, again, eat  meat, we're eating animals that  broke down the carotene, the  vitamin A for us, but in other  cases we break it down ourselves  when we eat carrots.  And the process is like this.  And these are some examples of  structures of carotenes. 

 Zeta-carotene, lycopene, that's  the red pigment in tomatoes and  red carrots and watermelon,  gamma-carotene, alpha-carotene,  beta-carotene and retinol.  Another name for retinol is  vitamin A.  So, not to go into too much  detail, but take a look at this  beta-carotene.  If you cut it in half and add a  couple of hydroxyls, you get two  molecules of retinol or  vitamin A for each molecule  of beta-carotene.  And so in this process of us  eating carotene, we break down  the beta-carotene to retinol  and, consequently, get the  vitamin A by eating things like  carrots.  And, in fact, vitamin A is a  essential nutrient.  We have to have vitamin A in our  diet, not every day because in  the case of vitamin A because  it's fat stored.  In fact vitamin A deficiency is  pretty rare in the US and  developed countries.  There are some populations in  the US that are suboptimal in  their consumption of vitamin A  and they're supposedly at risk  but physicians tell me they  rarely see it.  But if you go to the developing  world, the story is very  different. 

 Yes?  >> What is the definition of a  vitamin?  Is it its chemical composition  or does it also improve its  purpose and what it does  nutritionally?  >> The question is what is the  definition of a vitamin.  First of all, a vitamin is an  essential nutrient, it's not  something we can get by without  eating.  If you have complete lack of a  vitamin in your diet, you'll  have some very severe  nutritional problems.  Each of the vitamins has their  own function, their own chemical  property, and those properties  that come along with those  things we call vitamins are how  they are defined.  So I'm not sure if that really  answered your question.  >> Well, what is the common,  lots of things have chemical  compositions, so what makes a  vitamin a vitamin?  >> So the question is a lot of  chemicals have chemical  compositions and when we eat  them, I'll add a little more to  what you said, when we eat them  they have an affect, sometimes  good, sometimes bad, on us, how  does that make it a vitamin?  Vitamins is a short list of  chemicals that has a very  specific and essential function  in health.  Let's see, going back to  something like lycopene, that's  not a vitamin, it's a carotene  and it's a pigment similar to  beta-carotene but it's not  essential that we have lycopene  in our diet.  When we have lycopene in our  diet, it does protect us from  some forms of cancer apparently,  but it's not essential.  So the essentiality is what  defines a vitamin.  So we'll talk about that later  if there's more questions on  that, if you don't mind. 

 But vitamin A is an essential  nutrient, and it's a big problem  in that it's short in supply in  the developing world.  It's the most frequent  nutritional disease after the  diseases of energy and protein  deficiency, and it's estimated  that about 140 million  subclinical cases of vitamin A  deficiency occur every year,  mainly in children, and what  results from this is the initial  signs of vitamin A deficiency,  that including reduced immune  function and lowered disease  resistance.  And what that means is that a  disease like measles can kill a  child with vitamin A suboptimal  consumption.  And if the deficiency is more  extreme, the individual becomes  permanently blind.  There's reversible blindness  and then there's eventually  a permanent blindness.  And there's many people blinded  every year due to vitamin A  deficiency.  And, in fact,  it's estimated from 1.2  to 1.3 million individuals,  mainly children, die every year  from vitamin A deficiency  as their prime cause of death.  So it's a big problem in the  developing world.  So carrot is really an example  of where we could have an  agricultural intervention for a  health problem by looking at  improving carrots as a source of  vitamin A.  And, in fact, carrots in the US  have improved in vitamin A  content over time for looking at  the US crop because it's the one  we have the best records on. 

 Now these changes in vitamin A  content, excuse me, in carotene  content over time are the result  of classical plant breeding  where plant breeders like those  on this campus, WH Gobbleman and  CE Peterson, were breeding in  the 1950s.  And the average carrot in the  1950s had about 60 parts per  million carotene.  That doesn't mean anything to  you and I'll relate those  numbers to something more, well,  on the bottom I did.  The content moved up from 60 to  90 in the 1970s to 130.  That translate to somewhat  darker orange carrots.  And so the carrot of today has  about 130 parts per million  carotenes, and that means that  two-thirds of a whole carrot is  enough if that was the only  source of vitamin A in the diet.  We have many other sources of  vitamin A in the diet besides  carrots so that's one reason we  don't have much vitamin A  deficiency.  Yes?  >> Is there is difference in the  taste between those parts?  >> The question is, is there a  difference in taste to go with  the carotenes.  None at all, no, that's a great  question.  We were worried about that  because, in fact, the flavor  compounds are in the same  biochemical pathway as these  vitamins, these provitamin  carotenes. 

 But you can have really good  tasting or really poor tasting  white carrots or purple ones or  red ones or dark orange or light  orange, it's unrelated to color.  So with the process of plant  breeding in the last 50 to 60  years, there's been a doubling  of carotene content in carrots.  Here's what some of these color  differences look like.  It's not all that striking.  In the middle is a carrot of 140  parts per million.  That was a starting population  of some research we did.  And we developed carrots from  that with 270 parts per million,  another population with almost  500 parts per million.  The shape of the carrot changes  a little bit.  The intensity of the color  changes but you say they're  all orange carrots.  So with carrot breeding we've  improved or increased carotene  content quite substantially so  that, today, carrots are the  single most plentiful source of  the provitamin A carotenes in  the diet. 

 That's mainly beta-  and alpha-carotene.  In fact, carrots provide about  58% of the vitamin A coming from  plants, not all the vitamin A  but only the vitamin A coming  from plants, in the US diet.  The second highest is sweet  potatoes and tomatoes and some  from spinach, cantaloupe,  broccoli, lettuce and collards.  So, because of the importance of  vitamin A and because of the  interesting color differences,  we've been doing quite a bit of  research on this question of  what a carrot does to increase  its carotene content.  So we've made comparisons  between white rooted carrots,  both wild and cultivated like I  showed you, yellow rooted and  orange.  And, in fact, there's only one  gene difference between white  and yellow and then a second  gene difference between yellow  and orange.  I won't go into a lot of details  but just point out there were  these two genes that were  discovered by WH Gobbleman in  the Horticulture Department in  the '50s, '60s, and '70s.  So we've been looking a lot of  these genes because they're very  important, not only to the color  of carrots and appearance, but  also the nutritional value.  Because these carrots have no  carotene, white carrots.  I didn't mention that. 

 And yellow ones don't have any  beta-carotene either.  They have lutein but not  beta-carotene.  So where are we in understanding  this biochemical pathway,  biosynthesis of carotenes?  We're coming close to  understanding what exactly is  going on to answer this question  from a biochemical standpoint of  why carrots are orange.  So we're doing studies like this  where in this case we have two  different genes segregating, a  gene for yellow versus orange  and gene for purple versus  non-purple.  For purposes of this lecture  we'll only look at the  yellow/orange and we've located  that genomic chromosome.  And we've asked the question,  are these genes that control the  difference between white and  yellow and yellow and orange  carrots genes in the biochemical  pathway for carotenes?  This is the beginning of the  biochemical pathway for  carotenes.  Here's lycopene, the red  pigment; alpha- and  beta-carotene, the orange  pigments; yellow.  And so we know where these genes  are that account for the  pathway, the question is are  these the same genes as the Y  and Y2 genes that account for  color.  Turns out that if you look, this  is a map of carrot chromosomes,  lots of stuff here to look at.  The main points I'll point to is  that here's where the Y gene is,  here's where the Y2 gene is,  where you see red on here is  where the carotene enzymes are. 

 It turns out that there are some  enzymes close to these Y and Y2  genes but not quite right on  those genes.  So we can say that the Y and Y2  genes are not in the enzymes in  the biosynthesis of carrots but  they control the ability of  carrot cells to accumulate  carotenes.  This is important from the  standpoint of understanding  carotene metabolism which is  important for crop improvement,  not only carrots but other  crops, but also can give us some  insights to the history of  carrot domestication.  Again, we're coming close on  sequencing these genes, and when  we do we'll have a better handle  of how carrot cultivation came  about, domestication came about.  And we can then turn this  information from carrots around  and use it on other crops.  And, in fact, there are similar  genes in other crops like those  Y and Y2 genes of carrots.  In corn, potato, wheat, sweet  potato, melon, cucumber and  others we find similar genes,  and the question is how do we  apply this now to other crops.  The interesting thing is carrot  is the only one that has  carotene in the roots.  These are all other fruit and  tuber crops.  Now, I did mention that growers  realize no economic value from  high carotene carrots,  but consumers certainly do. 

 So we're doing this work  ultimately for consumers.  At the same time, though, to  help the growers out, we're  looking at improving flavor  because another way to get you  to increase your carotene  consumption is to just have the  same carotene content in a new  variety of carrots but with a  better flavor.  And I'll bet you that you'll eat  more carrots if it tastes  better.  And so there's really a couple  of approaches into increasing  carotene.  A direct one, just increasing  the content of carotene so each  mouthful you have has more  carotene in it or to get you to  eat more mouthfuls.  And this kind of information is  really critical to what's  referred to as this obesity  epidemic because if we want  people to eat more fruits and  vegetables, they're going to  have to want to eat them.  It's not something you can tell  people they should do.  Yes?  >> But on that point sometimes  we can be going in the opposite  direction.  We are not bringing some carrots  that have gone the way of some  breakfast cereal.  The amount of sweetness is 10  times what it was maybe 50 years  ago, and if anyone looks at  what's called the glycemic  index, a glass of carrot juice  will set your blood sugar up  soaring. 

 >> Right.  >> And we may be going in the  wrong directions by breeding  solely for flavor and sugar  content.  >> Right.  So the point was that breeding  for flavor can have it's  downfall.  The interesting thing with  carrots is that sweeter carrots  don't necessarily have more  carotene.  It's the succulents in a whole  carrot that translates to  sweetness.  And that's one interesting fact  that in fact you can have a  lower carotene, I said carotene,  sweeter carrots don't  necessarily have more sugar.  Sweeter carrots don't  necessarily have more sugar.  They can have the same amount of  carotene, that's independent of  sweetness and sugars.  A more succulent carrot gives  the impression of being sweeter. 

 We've demonstrated that in taste  panels.  And so breeding for more  succulence translates to what we  perceive as sweeter, and, at the  same time, you can have the same  sugar levels.  Now, breeding for higher sugars  can have this downfall of  increasing the glycemic index,  and for those with negative  health effects that can be  gained from that, that's  something to bear in mind.  So carrots is not a Paniceae.  It's a vehicle that I look at as  a way to help solve some  problems, and sometimes when you  one problem you might be  increasing another.  So watch out.  But we try to keep these things  in mind and do the best we can  as we're moving along.  Here are some other examples of,  I told you about, genetic  variation for carotene content  in carrots.  Here's some other fruits and  vegetables with carotene content  variation.  So here's a test for you. 

 So what's this one?  What do we got here?  >> Sweet potato.  >> Sweet potato.  Okay, I think everybody will get  that one right.  So you can see a wide range of  carotene content in sweet  potato.  These have none, these have  more.  What's this?  >> Papaya.  >> Papaya.  So there are other colors of  papaya, as well.  And so darker orange means more  carotene.  What's that?  >> Cucumber. 

 >> It's a cucumber, yeah.  We found the gene for orange and  carotene content in Chinese  cucumbers and we bred it into  some US varieties.  So you could have high carotene  cucumbers too.  How about this?  >> Bananas.  >> Bananas, yeah.  I heard plantains and bananas.  So there are deep orange  bananas, mainly out of New  Guinea and that area, that are a  very good source of vitamin A.  So where are we at with this  development of high carotene  carrots today?  Well, for one thing is we've  increased the dollar value of  the crop to growers, something  we always pay attention to.  In 2005 dollars it's increased,  I didn't calculate the  percentage, but substantially  in the US annually from  $470 million to $650 million.  At the same time, the per capita  consumption of carrots has gone  up quite substantially, mainly  due to baby carrots, and the  carotene content has also gone  up due to classical breeding so  that today more of our vitamin A  comes from carrots than did in  1975, almost 50% more. 

 So we've made quite a bit of  progress both in carrot dollar  value, carrot consumption and in  vitamin A content.  Now, we've done this with  carrots, can we apply this to  other crops?  I've showed you genetic  variation for these nutrients in  other crops and we could apply  this to other crops, but, in  fact, the nutritional values of  few crops have increased mainly  because there hasn't been a lot  of focus on this.  There's lots of opportunities to  increase the nutritional value  of all crops, including carrots.  But things like the provitamin A  carotenes in some crops I  mentioned, lots of variation for  vitamin C level, folate level,  niacin, tocoferol, these are all  vitamins, essential minerals,  and then some phytonutrients.  The question was what's a  vitamin?  There are other compounds in  plants that are nutritious but  not required, and so things like  antioxidants, lycopene, lutein,  resveratol, are associated with  better health and all of these  are genetically variable and  also vary, to some extent,  due to production practices.  And so in agricultural we could  improve the nutritional value of  all these crops.  To do this is going to take  better cooperation between those  of us in agricultural and those  in health area.  And we're doing that.  There's a ways to go for sure,  but we're making progress.  One example of where we could  improve some nutrient is  magnesium, an essential mineral. 

 There's a wide genetic range of  variation for magnesium,  three-fold in carrots, two-fold  in potatoes.  Not much chance to improve  magnesium content in apples,  somewhat variable in oranges and  bananas, and this is a current  content.  You can see that these values,  through breeding alone, could  increase magnesium content.  Some examples of other things we  could do with breeding for  nutritional value.  So just to recap, the  domestication of plants and  animals was certainly a  significant human achievement.  And there's a huge part of the  world population today that's  completely stuck on agriculture  because if it weren't for  agriculture there would be  massive starvation.  It's not something we can turn  back on at all very easily.  And we are, most humans today,  are very much dependent on  domesticated plants, not only  for food but for other things as  well.  And, in fact, as I see it,  it's our responsibility as  agricultural scientists to  increase food quantity and  quality as we go along.  As we do that, starvation and  malnutrition will continue, part  of that is due to agricultural,  part of that is do to social  pressures, but we certainly, in  my opinion, should do what we  can. 

 But these are not simple  solutions that are not things  individuals can be done and not  individual countries can be  done, it's a group effort.  In the same way that raising the  crop, this is a picture from  Wisconsin in the 1800s, raising  this crop was a family effort to  get this abundant collection of  vegetables on this table.  And my research is a team  effort, too, where we've had the  luxury of having a fairly large  number of grad students, support  scientists and funding from  different sources to support  this work.  So that to modify this picture  from the 1800s, pulling stumps  they found a carrot in this  case.  That's not really me with my  beard when it was darker.  So with that, I'll wrap it up.  Some Web site information,  contact if you have questions or  information you can contact me  that way or you can  ask questions now.  [APPLAUSE]