The Role of Source-Sink Relations between Photosynthetic and Assimilate-Consuming Organs in Regulation of Plant Photosynthesis

Abstract

Cause and effect relationships between chloroplast photochemical reactions, CO 2 assimilation and oxygen photosynthetic metabolism, transport of sugars in the phloem, apoplastic invertase and leaf stomata activity have been established. Regulation of photosynthesis at the level of an assimilate donor leaf with the change of illumination or export of products of photosynthesis is effectuated as follows. In case of deficiency of products of chloroplast photochemical reactions there occurs incomplete regeneration of resulting primary CO 2 fixation products and rapid accumulation of oxygenated substances in cells, vacuoles and the apoplast of the leaf. Apoplastic fluid pH decrease activates the invertase and intensifies the sucrose splitting in the apoplast, which increases the osmolality of extracellular environment that is increased approaching the guard cells, where the main evaporation of water takes place. The osmolality of extracellular environment decreases the turgor of the guard cells and increases the resistance of СО 2 diffusion into the leaf.

Leaf Pigment, Phenolic Content, and Production of Green Shallot of Five Different Shallot Varieties

“…The low pigment content in 'Bantaeng' variety manifests its effectiveness in photosynthesis performance viewed from the production side. Photosynthesis is not only related to the leaf photosynthesis pigment but also related to many other factors such as nutrient absorption and storage capacity for both photosynthetic and nutrient products (Chikov, 2017). The source and sink relationship in 'Bantaeng' variety could be one of the crucial genetic traits that distinguish it from other varieties.…”

Utilization of spare substances of Zea mays L. seeds during germination under the combined effect of growth regulators and presence or absence of light

“…Nowadays, the most studied type of these relationships is the interaction of photosynthesis (source) and the processes of vegetative growth (sink) of the assimilates (Sugiura et al, 2015;Humplík et al, 2015;Chikov, 2017; Khodanitska, Shevchuk et al, 2019). Furthermore, the issues of the source-sink system functioning during heterotrophic phase of plant development as the period of seed germination and formation of other organs remain practically unspecified.…”

Regulation of Donor-Acceptor Relations in the System of Deposition of Assimilates – Growth in Legume Plants during Germination

“…The analysis of the literature revealed that under shortage conditions of photochemical reactions' products, incomplete restoration of the productivity level of total CO 2 fixation and the rate of oxidized compounds assimilation in the cell, vacuoles and apoplast of leaves was observed and the pH of the apoplastic fluid increased the invertase activity, stimulating the cleavage of the sucrose in the apoplast of the leaf [1].…”