# Genome-Wide Analysis of the RbcS Gene Family and Expression Analysis Under Light Response in Brassica napus L

## TL;DR

This study explores the RbcS gene family in Brassica napus to understand its role in photosynthesis and how it responds to light, aiming to improve crop yield.

## Contribution

The study provides a comprehensive genome-wide analysis of RbcS genes in Brassica species and identifies potential targets for improving photosynthetic efficiency.

## Key findings

- 61 RbcS genes were identified across multiple Brassica species and their diploid progenitors.
- Promoter analysis suggests RbcS genes may be regulated by light-inducible promoters.
- Haplotype variations offer insights for selecting germplasm with high photosynthetic potential.

## Abstract

Enhancing photosynthetic efficiency represents a key approach for improving crop biomass, with its translation into higher grain yield being contingent upon the efficiency of photosynthate partitioning toward harvestable organs. The Rubisco small subunit (RbcS) gene family plays an essential role in this process by stabilizing and regulating Rubisco assembly and activity during photosynthesis. In this study, we identified 61 RbcS genes across B. napus, B. juncea, and B. carinata, and their diploid progenitors B. rapa, B. nigra, and B. oleracea by genome-wide screening and bioinformatic approaches. Phylogenetic relationships, gene structures, conserved domains, collinearity, cis-regulatory elements, expression profiles, and haplotype variations were systematically investigated, revealing the potential functional role significance and regulatory complexity of RbcS genes in photosynthesis. The results imply that the promoter type of this gene family may belong to light-inducible promoters. Furthermore, while a haplotype analysis provided valuable insights for selecting germplasm with potentially high photosynthetic efficiency, definitive confirmation of their effects requires functional validation. Collectively, our results establish a theoretical foundation for understanding the molecular mechanisms of BnRbcS genes and propose candidate genetic targets for further exploration to enhance photosynthetic performance in rapeseed breeding.