Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata - CONICET, CC1245 (7600) Mar del Plata, Argentina.
New Phytol. 2010 Dec;188(4):977-84. doi: 10.1111/j.1469-8137.2010.03465.x. Epub 2010 Sep 9.
Hydrogen sulphide (H(2) S) has been proposed as the third gasotransmitter. In animal cells, H(2) S has been implicated in several physiological processes. H(2) S is endogenously synthesized in both animals and plants by enzymes with l-Cys desulphydrase activity in the conversion of l-Cys to H(2) S, pyruvate and ammonia. The participation of H(2) S in both stomatal movement regulation and abscisic acid (ABA)-dependent induction of stomatal closure was studied in epidermal strips of three plant species (Vicia faba, Arabidopsis thaliana and Impatiens walleriana). The effect of H(2) S on stomatal movement was contrasted with leaf relative water content (RWC) measurements of whole plants subjected to water stress. In this work we report that exogenous H(2) S induces stomatal closure and this effect is impaired by the ATP-binding cassette (ABC) transporter inhibitor glibenclamide; scavenging H(2) S or inhibition of the enzyme responsible for endogenous H(2) S synthesis partially blocks ABA-dependent stomatal closure; and H(2) S treatment increases RWC and protects plants against drought stress. Our results indicate that H(2) S induces stomatal closure and participates in ABA-dependent signalling, possibly through the regulation of ABC transporters in guard cells.
硫化氢（H2S）被认为是第三种气体递质。在动物细胞中，H2S 参与了几种生理过程。H2S 在动物和植物中都是由具有 l-Cys 脱硫酶活性的酶通过将 l-Cys 转化为 H2S、丙酮酸和氨来内源性合成的。在三种植物（蚕豆、拟南芥和凤仙花）的表皮条中研究了 H2S 在气孔运动调节和 ABA 依赖性诱导气孔关闭中的参与。H2S 对气孔运动的影响与受到水分胁迫的整个植物的叶片相对含水量（RWC）测量进行了对比。在这项工作中，我们报告外源性 H2S 诱导气孔关闭，并且这种效应被 ATP 结合盒（ABC）转运蛋白抑制剂格列本脲削弱；清除 H2S 或抑制负责内源性 H2S 合成的酶部分阻断 ABA 依赖性气孔关闭；H2S 处理增加 RWC 并保护植物免受干旱胁迫。我们的结果表明，H2S 诱导气孔关闭，并参与 ABA 依赖性信号转导，可能通过调节保卫细胞中的 ABC 转运蛋白。
