English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The results of long-term studies of photorespirationare summarized and the unsuccessful attempts to increase productivity bysuppressing this process are shown. It has been shown that photorespiration andglycolate metabolism are involved in the regulation of the relationship betweenlight processes in chloroplasts and the dark reactions of carbon dioxideassimilation. The studies were conducted on plants in vivo and were associated with the activity of the apoplasticinvertase enzyme, affecting assimilate transport. In violation of donor-acceptorrelations between photosynthetic and plant-assimilating organs (removal of partof organs-consumers of assimilates or leaves, increase in nitrate nutrition),the kinetics of inclusion of 14C in glycolate was changed. This isdue to the strengthening of the role of the transketolase mechanism of itsformation. The study of genetically transformed plants, in which either anadditional apoplastic invertase gene was introduced, or the existing gene wasblocked and did not act, showed a different change in the ratio of 14C-labeledsucrose/hexose and the transpiration response to reduced light. In thisconnection, the concept of the mechanism of photorespiration interaction withapoplastic invertase and stomatal apparatus of the leaf is proposed when the ratioof light and dark reactions of photosynthesis or assimilate transport ischanged. The essence of the concept is that when the ratio of light and darkprocesses is disturbed, the concentration of organic acids changes first inmesophilic cells (mainly by photorespiration), and then in the extracellularspace. It changes the activity of apoplastic invertase, which hydrolyzessucrose and prevents it from being exported from the leaf. Hydrolysis ofsucrose increases the osmoticity of theaquatic environment of the apoplast, which increases with movement to thestomata. The changed osmoticity of theenvironment around the stomatal guard cells changes the resistance of CO2 diffusion into the leaf. This normalizes the ratio of light and dark processesin the sheet. Therefore, when illumination decreases, nitrate nutritionincreases or difficulties arise with the use of photosynthesis products inacceptor organs, the ratio of 14C-labeled sucrose/hexose decreases,and the stomata close. With increasing illumination, reverse events occur.

Photorespiration and Its Role in the Regulation of Photosynthesis and Plant Productivity