School of Life Science, Shanxi University, Taiyuan 030006, China.
Biochem Biophys Res Commun. 2011 Oct 28;414(3):481-6. doi: 10.1016/j.bbrc.2011.09.090. Epub 2011 Oct 2.
Hydrogen sulfide (H(2)S) plays a crucial role in human and animal physiology. Its ubiquity and versatile properties have recently caught the attention of plant physiologists and biochemists. Two cysteine desulfhydrases (CDes), L-cysteine desulfhydrase and D-cysteine desulfhydrase, were identified as being mainly responsible for the degradation of cysteine in order to generate H(2)S. This study investigated the expression regulation of these genes and their relationship to drought tolerance in Arabidopsis. First, the expression pattern of CDes in Arabidopsis was investigated. The expression levels of CDes gradually increased in an age-dependent manner. The expression of CDes was significantly higher in stems and cauline leaves than in roots, rosette leaves and flowers. Second, the protective effect of H(2)S against drought was evaluated. The expression pattern of CDes was similar to the drought associated genes induced by dehydration, and H(2)S fumigation was found to stimulate further the expression of drought associated genes. Drought also significantly induced increased H(2)S production, a process that was reversed by re-watering. In addition, seedlings after treatment with NaHS (a H(2)S donor) showed a higher survival rate and displayed a significant reduction in the size of the stomatal aperture compared to the control. These findings provide evidence that H(2)S, as a gasotransmitter, improves drought resistance in Arabidopsis.
硫化氢 (H(2)S) 在人类和动物生理学中起着至关重要的作用。其无处不在和多功能的特性最近引起了植物生理学家和生物化学家的关注。两种半胱氨酸脱硫酶 (CDes)，L-半胱氨酸脱硫酶和 D-半胱氨酸脱硫酶，被确定为主要负责降解半胱氨酸以生成 H(2)S。本研究调查了这些基因的表达调控及其与拟南芥耐旱性的关系。首先，研究了 CDes 在拟南芥中的表达模式。CDes 的表达水平随年龄的增长呈逐渐增加的趋势。CDes 在茎和茎生叶中的表达明显高于根、莲座叶和花。其次，评估了 H(2)S 对干旱的保护作用。CDes 的表达模式与脱水诱导的干旱相关基因相似，并且发现 H(2)S 熏蒸进一步刺激了干旱相关基因的表达。干旱还显著诱导 H(2)S 产生增加，复水后这一过程得到逆转。此外，用 NaHS（H(2)S 供体）处理后的幼苗存活率更高，与对照相比，气孔开度明显减小。这些发现为 H(2)S 作为一种气体信号分子提高拟南芥耐旱性提供了证据。
