Identification and functional characterization of a cystathionine β-lyase (CBL) enzyme for H2S production in Arabidopsis thaliana
2022
Wang, Zhiqing | He, Feng | Muyao, | Zhang, Liping | Liu, Zhiqiang | Liu, Danmei | Yang, Jinbao | Jin, Zhuping | Pei, Yanxi
Sulfide or sulfur metabolism plays an important role in the growth and development of plants. Cystathionine β-lyase (CBL) is an important enzyme in methionine synthesis, but a comprehensive understanding of CBL functions is limited. As the third gasotransmitter, hydrogen sulfide (H₂S) plays important physiological roles in plants. In this study, we found that the endogenous H₂S content in Arabidopsis thaliana cbl mutants was lower than that in the wild type. Under PEG-based osmotic stress conditions, the H₂S contents of CBL-overexpression (OE-CBL) plants increased significantly compared with the wild type. Additionally, the OE-CBL plants increased their tolerance to osmotic stress by increasing the transcription levels of drought-related genes and their relative water-loss rates. Compared with cbl and wild type, OE-CBL plants resisted drought stress by significantly closing their stomata, resulting in improved survival rates. Root tip-bending experiments showed that CBL overexpression relieved osmotic, heavy metal and cold stresses in Arabidopsis. The recombinant CBL activity in vitro revealed that CBL produced H₂S using L-cysteine as a substrate. Thus, CBL had a very strong cysteine desulfhydrase activity that could produce endogenous H₂S using L-cysteine as a substrate, and it played an important role in plant abiotic stress resistance.
显示更多 [+] 显示较少 [-]