A putative rice l-cysteine desulfhydrase encodes a true l-cysteine synthase that regulates plant cadmium tolerance
- 37 Downloads
Recent years have witnessed tremendous progress in understanding the biological relevance of hydrogen sulfide (H2S) as the third gasotransmitter for multiple signaling events in plants. l-Cys desulfhydrase (LCD) catalyzes the formation of H2S by using l-Cys as a substrate. In previous studies, we detected LCD activity in rice, but the corresponding genetic information and its biological function in the alleviation of plant Cd toxicity are still unknown. In this study, a putative LCD gene (OsLCD2) with high homology to Arabidopsis LCD has been cloned in rice. Surprisingly, the biochemical characterization of the recombinant OsLCD2 protein suggests that this protein predominantly possesses cysteine synthesis activity rather than the degradation of cysteine to produce H2S, and thus, the gene has been renamed OsCS1. OsCS1 localizes inside the nucleus in rice protoplasts. Molecular evidence shows that OsCS1 mRNA is ubiquitously expressed in rice, and up-regulated by cadmium. It has been further observed that over-expression of OsCS1 in Arabidopsis results in the enhanced glutathione biosynthesis, which allows plants to tolerate cadmium stress. Overall, the above findings provide evidence that OsCS1 is a potentially important enzyme responsible for the synthesis of cysteine, which could provide a new information about the metabolism of H2S in plants.
Keywordsl-cysteine desulfhydrase Cysteine synthase Hydrogen sulfide Cadmium Glutathione
This research was funded by National Natural Science Foundation of China (31670255), Fundamental Research Funds for the Central Universities (KYZ201859), Natural Science Foundation of Jiangsu Province (BK20161447). The authors sincerely thank Dr Cecilia Gotor from Instituto de Bioquímica Vegetal y Fotosíntesis, Spain and International Science Editing (http://www.internationalscienceediting.com) for kind help in editing the manuscript.
- Cui WT, Chen HP, Zhu KK, Jin QJ, Cui J, Xie YJ, Zhang J, Shen WB (2014) Cadmium-induced hydrogen sulfide synthesis is involved in cadmium tolerance in Medicago sativa by reestablishment of reduced homoglutathione and reactive oxygen species homeostases. PLoS ONE 9:e109669CrossRefPubMedPubMedCentralGoogle Scholar
- Droux M, Ruffet ML, Douce R, Job D (1998) Interactions between serine acetyltransferase and O-acetylserine (thiol) lyase in higher plants: structural and kinetic properties of the free and bound enzymes. Biochem 255:235–245Google Scholar
- Jin ZP, Pei YX (2015) Physiological implications of hydrogen sulfide in plants: pleasant exploration behind its unpleasant odour. Oxid Med Cell Longev 2015:1–6Google Scholar
- Kubo A, Sano T, Saji H, Tanaka K, Kondo N, Tanaka K (1993) Primary structure and properties of glutathione reductase from Arabidopsis thaliana. Plant Cell Physiol 34:59–1266Google Scholar
- Pei YX (2016) Gasotransmitter hydrogen sulfide in plants: stinking to high heaven, but refreshing to fine life. China J Biochem Mol Miol 32:721–733Google Scholar
- Shen J, Zhang J, Zhou C, Zhou M, Zhou H, Cui B, Gotor C, Romero LC, Foyer CH, Pan Q, Wu D, Yin X, Liu X, Shen W, Cui W, Xie Y (2019) A persulfidation-based protein modification controls guard cell ABA signaling. CELL-REPORTS-D-19-02762. Available at SSRN: https://ssrn.com/abstract=3424315 or https://doi.org/10.2139/ssrn.3424315