Abstract:

Hydrogen sulfide (H₂S) is a newly-discovered signaling molecule in plants and has caused increasing attention in recent years, but its function in stomatal movement is unclear. In plants, H₂S is synthesized via cysteine degradation catalyzed by D-/L-cysteine desulfhydrase (D-/L-CDes). AtD-/L-CDes::GUS transgenic Arabidopsis thaliana (L.) Heynh. plants were generated and used to investigate gene expression patterns, and results showed that AtD-/L-CDes can be expressed in guard cells. We also determined the subcellular localization of AtD-/L-CDes using transgenic plants of AtD-/L-CDes::GFP, and the results showed that AtD-CDes and AtL-CDes are located in the chloroplast and in the cytoplasm, respectively. The transcript levels of AtD-CDes and AtL-CDes were affected by the chemicals that cause stomatal closure. Among these factors, ACC, a precursor of ethylene, has the most significant effect, which indicates that the H₂S generated from D-/L-CDes may play an important role in ethylene-induced stomatal closure. Meanwhile, H₂S synthetic inhibitors significantly inhibited ethylene-induced stomatal closure in Arabidopsis. Ethylene treatment caused an increase of H₂S production and of AtD-/L-CDes activity in Arabidopsis leaves. AtD-/L-CDes over-expressing plants exhibited enhanced induction of stomatal closure compared to the wild-type after ethylene treatment; however, the effect was not observed in the Atd-cdes and Atl-cdes mutants. In conclusion, our results suggest that the D-/L-CDes-generated H₂S is involved in the regulation of ethylene-induced stomatal closure in Arabidopsis thaliana.

Hou Z, Wang L, Liu J, Hou L, Liu X (2013) Hydrogen sulfide regulates ethylene-induced stomatal closure in Arabidopsis thaliana. J. Integr. Plant Biol. 55(3), 277–289.

Key words: Desulfhydrase, D-/L-cysteine, ethylene, hydrogen sulfide, stomatal closure