# Genome-Wide Identification of DnaJ Gene Family and VIGS Analysis Reveal the Function of GhDnaJ316 in Floral Development for Upland Cotton

## TL;DR

This study identifies DnaJ genes in cotton and shows that GhDnaJ316 speeds up flowering, offering insights for breeding early-maturing cotton.

## Contribution

The study provides the first genome-wide identification and functional analysis of DnaJ genes in cotton, revealing GhDnaJ316's role in floral development.

## Key findings

- 372 DnaJ genes were identified and classified into four clades in upland cotton.
- GhDnaJ316 was functionally validated as a negative regulator of floral transition, accelerating flowering in silenced plants.
- Transcriptomic analysis showed tissue-specific expression patterns of GhDnaJ316 in anthers and filaments.

## Abstract

DnaJ proteins are established regulators of multiple physiological processes in plants, but their systematic identification and functional characterization in cotton remains largely uncharacterized, particularly regarding their roles in floral developmental regulation. In this study, based on genome-wide analysis of Gossypium hirsutum L., 372 DnaJ genes were systematically identified and phylogenetically classified into four distinct clades (I–IV). These genes exhibited non-uniform chromosomal distribution. Structural analysis revealed clade-specific variations in intron numbers and conserved motifs. Cis-acting element profiling indicated the roles of DnaJs in modulating biosynthetic and metabolic regulation during both vegetative and reproductive development in cotton. Transcriptomic analysis highlighted tissue-specific expression patterns, with GhDnaJ316 showing preferential expression in anthers and filaments. Functional validation via VIGS-mediated silencing confirmed GhDnaJ316 as a negative regulator of floral transition, accelerating budding by 7.7 days and flowering by 9.7 days in silenced plants. This study elucidates the genomic architecture of GhDnaJs, demonstrates GhDnaJ316’s critical role in floral development and provides insights for molecular breeding in early-maturing cotton.