GhSERAT1 enhanced the resistance of cotton to cadmium by maintaining the microscopic integrity of chloroplasts in cotton

Abstract

Cysteine metabolism is essential for plants to alleviate cadmium (Cd²⁺) stress. Investigating the function of serine acetyltransferase (SAT), the pivotal enzyme in cysteine synthesis, in combating Cd²⁺ stress is highly significant. This study conducted a bioinformatics analysis of the SAT gene family and identified key candidate genes, GhSERAT1;1 and GhSERAT1;2, that respond to Cd²⁺ stress. Plants subjected to gene silencing of GhSERAT1;1 and GhSERAT1;2 through virus-induced gene silencing exhibited a notable reduction in cysteine and glutathione levels, an increase in intracellular malondialdehyde content, and heightened sensitivity to Cd²⁺ stress. Compared with non-silenced plants, those with silenced genes displayed poorer growth conditions, decreased biomass, and more pronounced damage to chloroplast and leaf structures when exposed to Cd²⁺ stress. This study integrated the primary enzyme involved in cysteine synthesis with Cd²⁺ stress, elucidating the relationship between Cd²⁺ and cysteine. These findings significantly enhance our understanding of cysteine synthesis genes and contribute to developing Cd²⁺-resistant plant breeding strategies.