Regulation of growth in peach roots by exogenous hydrogen sulfide based on RNA-Seq.

Hydrogen sulfide (HS) has been shown to regulate many physiological processes of plants. In this study, we observed that 0.2 mM sodium hydrosulfide (NaHS), a donor of HS, can regulate the root architecture of peach seedlings, increasing the number of lateral roots by 40.63%. To investigate the specific mechanisms by which HS regulates root growth in peach, we used RNA sequencing and heterologous expression technology. Our results showed that exogenous HS led to a 44.50% increase in the concentration of endogenous auxin. Analyses of differentially expressed genes (DEGs) revealed that 963 and 1113 genes responded to HS on days one and five of treatment, respectively. Among the DEGs, 26 genes were involved in auxin biosynthesis, transport, and signal transduction. Using weighted correlation network analysis, we found that the auxin-related genes in the HS-specific gene module were disproportionately involved in polar transport, which may play an important role in HS-induced root growth. In addition, we observed that the expression of LATERAL ORGAN BOUNDARIES DOMAIN 16 (PpLBD16) was significantly up-regulated by exogenous application of HS in peach. Overexpression of PpLBD16 in an Arabidopsis system yielded a 66.83% increase in the number of lateral roots. Under exposure to exogenous HS, there was also increased expression of genes related to cell proliferation, indicating that HS regulates the growth of peach roots. Our work represents the first comprehensive transcriptomic analysis of the effects of exogenous application of HS on the roots of peach, and provides new insights into the mechanisms underlying HS-induced root growth.