Related Experiment Video
Updated: Jun 18, 2025

Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean
Published on: December 23, 2017
Duplication and sub-functionalization of flavonoid biosynthesis genes plays important role in Leguminosae root nodule
Tengfei Liu1,2, Haiyue Liu2,3, Wenfei Xian4,5
1Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Abstract:
Gene innovation plays an essential role in trait evolution. Rhizobial symbioses, the most important N2-fixing agent in agricultural systems that exists mainly in Leguminosae, is one of the most attractive evolution events. However, the gene innovations underlying Leguminosae root nodule symbiosis (RNS) remain largely unknown. Here, we investigated the gene gain event in Leguminosae RNS evolution through comprehensive phylogenomic analyses. We revealed that Leguminosae-gain genes were acquired by gene duplication and underwent a strong purifying selection. Kyoto Encyclopedia of Genes and Genomes analyses showed that the innovated genes were enriched in flavonoid biosynthesis pathways, particular downstream of chalcone synthase (CHS). Among them, Leguminosae-gain type Ⅱ chalcone isomerase (CHI) could be further divided into CHI1A and CHI1B clades, which resulted from the products of tandem duplication. Furthermore, the duplicated CHI genes exhibited exon-intron structural divergences evolved through exon/intron gain/loss and insertion/deletion. Knocking down CHI1B significantly reduced nodulation in Glycine max (soybean) and Medicago truncatula; whereas, knocking down its duplication gene CHI1A had no effect on nodulation. Therefore, Leguminosae-gain type Ⅱ CHI participated in RNS and the duplicated CHI1A and CHI1B genes exhibited RNS functional divergence. This study provides functional insights into Leguminosae-gain genetic innovation and sub-functionalization after gene duplication that contribute to the evolution and adaptation of RNS in Leguminosae.
Related Concept Videos
Gene Duplication and Divergence
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are...
Gene Families
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
The Roles of Bacteria and Fungi in Plant Nutrition
Non-vascular Seedless Plants
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...

