A collaborative research team led by Professor TIAN Zhixi from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences investigated the correlation between Leguminosae-gain gene duplication patterns and their function in root nodule symbiosis (RNS).

Gene innovation plays an essential role in trait evolution. Rhizobial symbioses, the most important N2-fixing agent in agricultural systems existing mainly in Leguminosae, is one of the most attractive evolution events. Although functional RNS genes have been widely investigated among Leguminosae plants, the correlation between Leguminosae-gain gene duplication patterns and their function in RNS has not been well investigated.

In this study, researchers determined 229 manual checked Leguminosae-gain orthologous groups by conducting phylogenomic analysis of 48 Leguminosae and non-Leguminosae species.

They found that the Leguminosae-gained genes acquired by duplication were enriched in flavonoid pathways. Among them, Leguminosae-gain duplicated CHI genes experienced significantly structural divergence.

Further systemic investigation demonstrated that CHI1B but not its duplicated gene CHI1A enhanced nodulation in Leguminosae.

Their study revealed that duplication and sub-functionalization of flavonoid biosynthesis genes play important role in Leguminosae root nodule symbiosis.

These findings provide functional insights into Leguminosae-gain genetic innovation and sub-functionalization after gene duplication that contribute to the evolution and adaptation of RNS in Leguminosae.

This work was funded by the National Natural Science Foundation of China, “Strategic Priority Research Program” of the Chinese Academy of Sciences, CAS Project for Young Scientists in Basic Research, and the Xplorer Prize.

Their findings were published in J. Integr. Plant Biol..