An Academic Valentine: The Science Behind Flower Color

An Academic Valentine: The Science Behind Flower Color

Morning Glory Buds are Red

And they Open to Bright Blue

But in NHX1 Mutants

They can’t Change their Hue

✿ We all know that roses are red and violets are blue, but did you also know that vacuolar pH determines their hue? Flowers are colored by anthocyanin pigments that collect in the vacuoles of petal cells. Their color is determined by the acidity, or pH of the vacuole. Vacuolar pH is set by a balance of proton (H+) pumps and leaks. A family of leak proteins known as sodium hydrogen exchangers is found in all cells from yeasts, plants and animals. They work to keep vacuoles and other cell compartments from becoming too acidic.A dramatic example is that of the Japanese morning glory (Ipomoea nil) where mutants in the leak protein, NHX1, fail to achieve that brilliant blue when they flower. The first NHX1 gene was cloned by our lab from yeast in the mid-nineties. More recently, mutations in the human genes have been linked to autism, Alzheimer’s disease, seizures and cognitive disabilities, in ways that we are only just beginning to understand.

#valentinesday    #AcademicValentine   #ScienceEveryday  

✿ Image: From the review by Jon Pittman 

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50 Responses to An Academic Valentine: The Science Behind Flower Color

  1. CK Feisal says:

    Happy valentines day, Rajini Rao 🙂

  2. Rajini Rao says:

    Hi there, CK Feisal . Lots of love to you and the family! 

  3. Happy Valentines Day dear Rajini Rao … .-)

    My best wishes for a joyful V-day to you and your beloved !!!

    Flower Power … 😉

  4. Rajini Rao says:

    Thanks, Magnus Fahlén . Much love and good wishes to our favorite Viking 🙂

  5. Thanks a lot sweetie … ^^

    Enjoying a short afternoon coffee break at work now and heading home soon … 🙂

    Take care and have fun !!

  6. CK Feisal says:

    Thank you Rajini Rao. We don’t celebrate but what the heck. Hehe. Much love to you n yours too.

  7. Rajini Rao says:

    Hehe, we are too lazy to follow the Hallmark protocol, but yes, what the heck 🙂

  8. Chad Haney says:

    Science Hallmark cards. I ♥ it. Great post and Happy St. Valentines Day WW.

  9. Rajini Rao says:

    Thanks, Gnotic Pasta . I’m sure the Dan Van is revved and ready for V-Day 😀

  10. Rajini Rao says:

    Chad Haney thanks for digging up your pink/blue hydrangea post. I love it! A wonderful addition to the #AcademicValentine explaining flower color:

  11. Chad Haney says:

    Rajini Rao I’m glad you didn’t say Dan’s Van was revved up for VD.

  12. Rajini Rao says:

    Yikes, haha! Actually, I just watched a WWII series last night and was thinking of Victory Day apropos Gnotic Pasta 😉

  13. Rajini Rao says:

    Gnotic Pasta , I’ve been revisiting Foyle’s War. A charming series, highly recommended. Set in southern England during WWII. 

  14. Rajini Rao says:

    Gnotic Pasta yes, it can be streamed from Netflix. Let me what you think of it! 

  15. Chad Haney says:

    My wifes watches Foyle’s War sometimes.

  16. Rajini Rao says:

    Lots of Spitfire action in Foyle’s War.


    Lol on Hatari: Was there a speckled mirror/feisty love scene in Hatari or was it just a figment of my imagination? 😛

  17. I like your concept, very nice explanation. You take my love & Thanks you.

  18. Kevin Clift says:

    ‘It’s a poor sort of memory that only works backwards.’  I was woken abruptly this morning and remembered the last image from my dream.  It was Michael Kitchen asking me to admire his German hunters’ jacket and his tweed hat with a small feather in it as he left for Germany.  Happy Valentine’s day!

  19. Rajini Rao says:

    Michael Kitchen is a pleasure to watch, Kevin Clift . I’m so glad that Foyle’s War is back. Oh, and much love and happiness in your circle of family and friends for Valentine’s day, Kevin. 

  20. Adam Gill says:

    Rajini Rao You mention sodium/proton exchangers (which I think NHX1 is), but you’ve got a potassium/proton antiporter in your image? Can they do both? That’s a little odd (at least in my limited reading!), normally these things are pretty specific. Is there more here than meets the eye?

  21. Rajini Rao says:

    Adam Gill , thanks for the question. The classical sodium/hydrogen exchangers reside on the plasma membrane of animal cells and are specific for sodium ions (they link to the external sodium gradient set up by the sodium pump). However, a subset of this family reside on endosomes and vacuoles. These evolved earlier and can transport both sodium and potassium in exchange for protons. This makes sense, since there is more potassium in the cytoplasm than sodium. They are all related at the level of DNA/protein sequence. 

  22. Great, very interesting. But just went over ???????

  23. Rajini Rao says:

    Vijai Chandra over, between or through the ears? 🙂 Any questions, do ask! 

  24. well got to think now, will surely ask questions.

  25. Great post. I wish all the scientists and educators write their work beginning with a rhyme. Am I the only one who found the rhyme wonderful?

  26. Rajini Rao says:

    Chaitanya Dev , thank you. I open my graduate/medical school lectures with a “science” song..I have the lyrics up on the screen, and I follow with a question based on the song. There are lots of clever and charming science versions of pop songs on the internet. One year, however, I did sing a little verse. It was a morning lecture, so I’m pretty sure I was not drunk 😉 It may have been pity, but that year one of the students in the lecture joined my lab and did an excellent PhD thesis with us. 

  27. Rajini Rao I would love to have a PhD guide like you. But I guess professors in the Rocket Propulsion department aren’t so cool. 🙂

  28. Rajini Rao says:

    That’s because they don’t need to resort to song and dance (or free beer!) to trap attract students 🙂

  29. Chad Haney says:

    Free beer? Where? Sign me up.

  30. Love it. Brilliant way to describe the science. “We all know that roses are red and violets are blue, but did you also know that vacuolar pH determines their hue?”  

  31. Rajini Rao says:

    I love to inflict bad rhyme on my unsuspecting friends, Cheryl Ann MacDonald . All the best of the day to you 🙂

  32. Too much Biology lessons for one day :)

  33. Rajini Rao says:

    ERNST-STEPHEN POMPILUS read half today and the rest tomorrow 😉

  34. look there are two kind of mimosaceae tentofluora and sensitiva  i prefer the second for her photo_mechanic system without coulor game!!!!!!!!!!  

  35. Bill Collins says:

    The diagram is excellent. And as always, I appreciate your thoughtful and detailed posts. Happy Valentine’s to you and yours!

  36. Rajini Rao says:

    Thanks, Bill Collins . Happy V-Day to you guys too, and hope you have a good weekend ahead 🙂 

  37. Stuti S A I says:

    Very interesting piece Rajini Rao 

    Thank you.

    What happens when flower gets wilted and begins to lose its shade? Vacuole begins to collapse, is it?

  38. Amit Kumer says:

    Nice arrangement’s

  39. Jaz Emminger says:

    This needs to be “What’s hot”…

  40. Thanks, cool stuff. But yesterday I learned from a friendly Dalek that Roses aren’t red but blonde, and Amys are red 😉

    Edit: I just saw (in a real computer) that my phone’s autocorrection had inserted an invisible “thanksgiving” and some empty lines before the beginning of this comment. Fixed.

  41. Flowers are a bit less complicated than women ! Good Valentine’s Day for everybody!

  42. Wow I didn’t know why roses are red! #anthocyanins  #pH

  43. Jaz Emminger says:

    Well, because roses are red.

    Wine is also red.

    Poems are hard.


  44. Rajini Rao says:

    Jaz Emminger : How about this?

    Cabernets are red

    Rieslings are white

    The ethanol in wine

    Makes the rhymes right.

    As for WH, I think the Google algorithm must take follower number as a denominator. So it becomes much harder to get a post on WH if the fraction of plusses/shares to the total number of followers is still small. Just a guess 🙂

  45. Rajini Rao says:

    Stuti S A I , you are absolutely right about wilting! Since plants have no internal skeleton, they use the water pressure of the vacuole pressing agains their outer cell wall to give them turgidity. Wilting happens when vacuoles lose water. Interestingly, the same gene mentioned here (NHX1) fills the vacuole with ions (sodium, potassium) that draw in water by osmotic pressure. 

  46. Stuti S A I says:

    Rajini Rao Thank you for responding to my query. 

    PS: I hold degrees in Humanities. Hence, my doubts.

  47. Rajini Rao says:

    Stuti S A I , love the questions..keep them coming! 🙂

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