The B3 gene family is a plant-specific transcription factor, playing a pivotal role in plant growth and development. It has been identified and reported in the whole genome sequences of many plant species, however, little is known about the B3 gene family in Medicago truncatula.

The research team from Wuhan Botanical Garden identified and characterized the B3 gene family from M. truncatula genome, predicted candidate genes associated with salt stress, and demonstrated its gene functions under salt stress.

The research identified a total of 173 members of the B3 gene family in M. truncatula, designated as MtB3-1 to MtB3-173, through genomic data analysis. The B3 gene family was further categorized into seven distinct subgroups. Moreover, it also found that some genes showed collinear relationships.

Expression analysis disclosed that 61 MtB3 genes exhibited diverse expression patters in various tissues under salt stress conditions, indicating their potential involvement in salt stress signaling response. Among them, MtB3-53 enhanced plant salt tolerance by regulating ion homeostasis and promoting the production of antioxidants, which helped alleviate cellular damage caused by salt stress.

This study lays a robust foundation for future investigations aimed at elucidating the functional significance of the B3 gene family and its role in regulating plant responses to salt stress.

This work was supported by the National Natural Science Foundation of China, the strategic Priority Research Program of Chinese Academy of Sciences, the Innovation Ability Improvement Project of Scientific and Technological SMEs in Shandong Province, the Major Science and Technology Innovation Project of Shandong Province, and the Science & Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta.

The results have been published in Plant Physiology and Biochemistry entitled “The B3 gene family in Medicago truncatula: Genome-wide identification and the response to salt stress”.

A combined NJ-based phylogenetic tree of MtB3 gene family (Image by WBG)

Subcellular localization and functional analysis of MtB3-53 (Image by WBG)