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

The research of the last decades was important for understanding the regularities of functioning the donor-acceptor system, which is a chief mechanism for the assimilate redistribution between plant organs in ontogenesis. By the dynamics of the change in the arrival of donor-acceptor assimilates, we may establish the regularities of the system functioning and the peculiarities of their endogenous regulation at the early stages of plant development, when the capacity of the “request” for the plastic substances for the acceptor, the sensitivity to the effects is the highest. The intensity of the usage of deposited substances in cotyledons and their redistribution between vegetative and generative organs of plants, bean-rhizobial complexes, which are additional consumers of assimilates in legumes, can become an indicator of regulation in ontogenesis phases, biochemical balance in plants and culture productivity. In modern literature, the information about the bacterothera acting as a consumer of assimilates in the process of symbiotic nitrogen fixation is negligible. Although it is clear that the capacity of the process of fixing atmospheric nitrogen is possible only in the conditions of plastic substances and energy inflow to the bacteroids, which can provide the process of photosynthesis by itself. Under shortage conditions of photochemical reactions' products, there is an incomplete restoration of the productivity level of total CO2 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. In addition, applied growth stimulants increase the dry mass of plants and the net productivity of photosynthesis contribute to the accumulation of various forms of carbohydrates in the roots and fruits. In stems and leaves there was a tendency of sugar and starch content decrease. Drugs significantly reduce the content of all forms of nitrogen in the roots, stems and fruits, and increase the content of protein nitrogen in the leaves. The drug induces a strong development of the photosynthetic apparatus: laying more leaves, prolonging their active functioning, increasing the size of chlorenchymal cells and chloroplastogenesis improving. This is accompanied by increase of plastic compounds formation in leaves, followed by their outflow to the generative organs that leads to carpogenesis intensification, increassing of yield quantity and improved yield structure, oil content and quality in flax seed was also improved. Light is one of the key factors in the environment which not only provides the process of autotrophic feeding, but also launches the program of photoromogenesis through the system of photoreceptors (phytochromes, cryptocrons, and phototropinum). This provides the de-etiolation, the formation of chloroplasts, leaf blades and, as a consequence provides the transition to autotrophic feeding. Seedlings in legumes, such as lupins, are endowed with a characteristic hypocotyle germinatting in the dark that demonstrates an exorbitantly high growth gradient with an elongated zone below the apex. Thus, germination in the dark - scotomorphogenesis is a regulator of inflow and outflow, accumulation of auxin in the hypocotyl growth zone.