Return to the Botany Forum | Post a Follow-Up

 o
Question regarding order of maturation

Posted by cinemike 8a (France) (My Page) on
Fri, Aug 23, 13 at 6:15

I have been fascinated and by the chance realisation that the inflorescence of plants can start low down, near the crown or start from the top. I gather these two 'orders of maturation' are called 'basipetal' and 'acropetal'.

My question is: what determines whether a plant is acropetal or basipetal, are there any other possibilities and does it occur always in families or are there both basipetal and acropetal plants in the same family or genus?


Follow-Up Postings:

 o
RE: Question regarding order of maturation

cinemike, I don't think I have ever seen an inflorescence open from the flower at the tip and work its way toward the base of the inflorescence. I may be wrong so please give me an example is you have one in mind. I'm not using basipetal and acropetal terminology because an inflorescence may stand upright or droop, depending on the plant.

I recently took a course in plant physiology and we did cover flowering, florigens, and flower signaling, but I don't remember having covered the way inflorescence opened. What I'm about to explain is my hypothesis for inflorescence maturation.

I think that florigens, flower-inducing hormones produced in the leaves, reach the base of the inflorescence and trigger those flowers to bloom. In the meantime, those blooming flowers produce antiflorigens. There are grafting experiments that support the existence of hormones that block flowering. I think that those antiflorigens delay the opening of the proceeding flowers. When the initial flowers reach a certain age, they may stop producing antiflorigens to allow the florigens to take effect on the next set of flowers. This is the most rational explanation I can think of.

What is harder to explain is how cucurbits open one male flower at a time from a set of 6 or 7 male flowers that form at one node. These flowers don't seem to be arranged into an inflorescence, yet the plant still manages to open just one male flower a day.

I used Plant Physiology 3rd ed. by Taiz and Zeiger as my reference.


 o
RE: Question regarding order of maturation

All of the plants from the family Asteraceae, as far as I can see open 'top down' (basipetal) - Inula, Cosmos, Erigeron etc.
Many plants in the Solanaceae family - notably Datura also evidence this.
As regards the curcurbits, surely it is the same effect as you mention. At a micro level there are the microbuds and each flower produces the antiflorigens until they die, then the next one in acropelal succession does its bit.

What I am looking for is some sort of explanation as to what determines whether an inflorescence is acropetal of basipetal, and if, for example it is some sort of evolutionary development that has divided plants into these two distinct groups.

From further reading, I have discovered that leaf development can be acropetal or basipetal.... so there is another question - must leaf development and flower development both be acropeatal or basipetal, or can there be basipetal leaves and acropetal flowers (or vice versa).... and, most importantly, what determines it?


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Botany Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here