ORIGINAL ARTICLE

Legume-rhizobial Symbiosis: Progress and Prospects

Data on the role of the legume-rhizobial symbiosis (LRS) in national economic and a brief history of the fundamental study of this unique biological phenomenon are summarized. The features of the formation of root nodules of determinant and indeterminant types are described. The physiological role of the rhizobial Nod factor in suppressing the defense system of a legume plant and the role of the plant's immune systems (MTI and ETI) in the rhizobial infection and the formation of LRS are discussed. Signal systems of a legume plant (Ca²⁺, NO-synthase, NADPH oxidase) and their components (ROS, RNS) and other signaling molecules involved and interacting in LRS onset are described. The necessity of studying the local and systemic resistsnce of the legume plant to the rhizobial infection is emphasized.