Searching for regulators that interact with BELL1 transcription factor and control the legume-rhizobial symbiosis development

Abstract

The development of nitrogen-fixing nodule, which is formed during legume-rhizobial symbiosis, requires the involvement of cell cycle regulators, phytohormones and homeodomain-containing transcription factors as well as other organogenesis processes. Along with homedomain-containing transcription factors from KNOX family, which participation in the control of nodule development has been studied recently, the role of transcription factors from BELL family in this process remains under-explored. At the same time, transcriptomic data for legumes shows an increase in the expression levels of genes encoding proteins of this family in the plant roots inoculated by Rhizobium. In this work we performed screening of сDNA library, which was generated from inoculated pea roots, using BELL1 protein in yeast two-hybrid system. As a result, we detected two interacting proteins, which are highly interesting for future examination. In the first case we discovered interaction between BELL1 and LysM-containing receptor-like kinase LYK9. Another identified regulator interacting with BELL1 became the glycine-rich protein A3, which may be involved in the regulation of defense reactions in plants and their resistance to phytopathogens. Transcriptomic analysis for pea roots has revealed high expression level of gene, which encodes this protein in the nodules, that may demonstrate its important role in symbiosis regulation.