Phytochrome B-dependent regulation of reductive phase of photosynthetic carbon assimilation

Phytochrome B-dependent regulation of reductive phase of photosynthetic carbon assimilation The experiments were conducted with 10-day-old seedlings of wheat (Triticum aestivum L). Phytochrome B was activated using an array of light diodes emitting light in the red spectral region (RL) and inactivated by an array of light diodes emitting far-red light (FRL). At the end of the night dark period (8 h), activity of the chloroplastic GAP-dehydrogenase complex (the sequence of reactions: 3-PGA → 1,3-PGA → 3-GAP) was 1.0−1.2 μmol of oxidized NADPH/(min g fr wt of the leaf). When the leaves of intact plants were exposed to a maximal dose of RL (20 min at 17.5 kJ/m2), enzyme activity rose by 100–120%. Longer exposure to RL (30 and 40 min) did not cause further activation. Successive exposure to RL and FRL (20 min at 3.0 kJ/m2) completely negated a stimulatory effect of RL. It was shown that as little as 5-min-long exposure to RL increased the rate of 3-GAP formation by 20–25%, and enzyme activity rose linearly when radiation dose was elevated. Determination of the lifetime of RL-activated state by its decrease in plants placed in darkness showed that decay occurred with τ1/2 of 50−60 min when RL was switched off. Thus, a phytochrome B-induced regulation of reducing enzyme complex governing the reductive pentose phosphate cycle was discovered. Judging from the kinetics of attenuation of the activated state, phytochrome B apparently does not affect de novo synthesis of the enzyme. Since the investigated metabolic process consists of two coupled reactions controlled by kinase and dehydrogenase, the place and mechanism of action of the phytochrome system remain unknown. Russian Journal of Plant Physiology Springer Journals

Phytochrome B-dependent regulation of reductive phase of photosynthetic carbon assimilation

Loading next page...
Pleiades Publishing
Copyright © 2017 by Pleiades Publishing, Ltd.
Life Sciences; Plant Physiology; Plant Sciences
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial