ВЛИЯНИЕ ИНТЕНСИВНОСТИ ОСВЕЩЕНИЯ НА РАСПРЕДЕЛЕНИЕ АУКСИНОВ МЕЖДУ ПОБЕГОМ И КОРНЕМ И ФОРМИРОВАНИЕ БОКОВЫХ КОРНЕЙ

Abstract

The influence of illumination on the level of endogenous auxins content and localization and their transport from shoots to roots in regulating lateral root branching of barley plants was investigated. The four times reducing of illumination was found to suppress the lateral roots formation in two days after beginning of exposure. The decrease in roots and shoots IAA content and in the intensity of phloem cells staining for auxins on leaf sections were observed already in a day after the light was reduced. A decline in auxin content in the roots was appeared to a greater extent compared to the shoots. At the same time, suppression of LAX3 gene responsible for the cell auxin influx was found in the roots along with a decrease in the rate of auxin flow through the phloem from shoots. It was assumed the inhibition of the lateral roots growth in barley under reduced level of irradiance in the photosynthetically active region was due to impaired phloem transport of auxin and a decrease in the level of expression of the auxin transporter in plant roots.