Abstract:

Hydrogen sulfide (H₂S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H₂S donor (sodium hydrosulfide, NaHS) and H₂S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H₂S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H₂S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H₂S level and decreased stress resistance. Moreover, H₂S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H₂S, and was related with H₂S-induced antibacterial resistance. Moreover, H₂S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H₂S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.

Shi H, Ye T, Han N, Bian H, Liu X, Chan Z (2015) Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis. J Integr Plant Biol 57: 628–640. doi: 10.1111/jipb.12302

Key words: Abiotic stress, auxin receptor, biotic stress, cysteine desulfhydrase, hydrogen sulfide, MIR393