Post a reply

Avatar for BeKind
Nov 27, 2015 7:47 PM CST
Thread OP
Ypsilanti, Michigan
Consider: By day, plants convert atmospheric carbon dioxide into starch and sugars. During the night, many species consume the starch stored during the day, thus avoiding starvation and maintaining plant productivity, including growth. Moreover, they process the stored starch at just the right rate​—not too quickly and not too slowly—​so that they use about 95 percent of it by dawn, when they start making more.
Image
Dec 1, 2015 2:46 PM CST
Baltimore County, MD (Zone 7a)
A bit of this and a bit of that
Charter ATP Member I was one of the first 300 contributors to the plant database! I helped beta test the Garden Planting Calendar Garden Sages The WITWIT Badge Herbs
Composter Container Gardener Seed Starter Vegetable Grower Dog Lover Garden Ideas: Master Level
Your first two sentences are spot-on. I think the rate of starch usage really depends on the plant and growing conditions, and can't be generalized so easily. After all, if a potato plant went through 95% of its starch reserves every night, we'd never get a harvest!
Image
Dec 1, 2015 2:55 PM CST
Name: Neal Linville
Winchester, KY (Zone 6a)
Bulbs Charter ATP Member Cottage Gardener I was one of the first 300 contributors to the plant database! Irises Roses
Celebrating Gardening: 2015 Garden Ideas: Level 2
I agree with bitbit. Perhaps somewhat true with annuals, but perennials store food (starch) to sustain during dormancy and regrowth. Most manufacture and store more than they need and contribute to the food chain while surviving and reproducing.
"...and don't think the garden loses its ecstasy in winter. It's quiet, but the roots are down there riotous." Rumi
Image
Dec 2, 2015 2:21 PM CST
Sweden
Forum moderator Garden Photography Irises Bulbs Lilies Bee Lover
Hellebores Deer Celebrating Gardening: 2015 Photo Contest Winner: 2016
BeKind said:Consider: By day, plants convert atmospheric carbon dioxide into starch and sugars. During the night, many species consume the starch stored during the day, thus avoiding starvation and maintaining plant productivity, including growth. Moreover, they process the stored starch at just the right rate​—not too quickly and not too slowly—​so that they use about 95 percent of it by dawn, when they start making more.

I heard a short version about this a while back, but never got around to reading up on it, so thanks for posting.

Short version here: https://www.jic.ac.uk/news/201...
More in depth here: http://elifesciences.org/conte...

Pretty fascinating stuff really. I'm assuming that the starch in the leaves that is consumed during night is somewhat separate from the starch content in say a root?
Image
Dec 2, 2015 4:58 PM CST
Name: Rick Corey
Everett WA 98204 (Zone 8a)
Sunset Zone 5. Koppen Csb. Eco 2f
Frugal Gardener Garden Procrastinator I helped beta test the first seed swap Plant and/or Seed Trader Seed Starter Region: Pacific Northwest
Photo Contest Winner: 2014 Avid Green Pages Reviewer Garden Ideas: Master Level Garden Sages I was one of the first 300 contributors to the plant database! I helped plan and beta test the plant database.
Hi William

>> I'm assuming that the starch in the leaves that is consumed during night is somewhat separate from the starch content in say a root?

I assume the same thing. They said:

"Photosynthetic starch reserves that accumulate in Arabidopsis leaves during the day decrease approximately linearly with time at night to support metabolism and growth."
- See more at: http://elifesciences.org/conte...

I didn't read past the point where they said they constructed some models, and that the measurements fit one or both of their models. That told me that they were not going to even speculate on the real mechanism, so I lost interest.

Whether or not Arabidopsis can or does mobilize [u]any[/y] starch reserves from stems or roots at night, or perhaps on nights where their "planning ahead" fell short, I don't know.

But "it makes sense" for a plant to have some long-term energy storage, and some short-term energy storage, and little reason they should both work the same way.

Elsewhere the authors say that daily-varying starch is stored "in plants" rather than saying "in plants' leaves", so I'm guessing there is variation in where "daily starch reserves" are stored, in different plants, or in genera other than Arabidopsis.

But we're both speculating.
Only the members of the Members group may reply to this thread.
  • Started by: BeKind
  • Replies: 4, views: 624
Member Login:

( No account? Join now! )

Today's site banner is by Fleur569 and is called "Hello Pumpkins.."

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.