Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
J Plant Physiol. 2012 Jul 1;169(10):979-86. doi: 10.1016/j.jplph.2012.02.007. Epub 2012 Mar 19.
Methylglyoxal (MG) is an oxygenated short aldehyde and a glycolytic intermediate that accumulates in plants under environmental stresses. Being a reactive α-oxoaldehyde, MG may act as a signaling molecule in plants during stresses. We investigated whether MG induces stomatal closure, reactive oxygen species (ROS) production, and cytosolic free calcium concentration (Ca²⁺) to clarify roles of MG in Arabidopsis guard cells. MG induced production of ROS and Ca²⁺ oscillations, leading to stomatal closure. The MG-induced stomatal closure and ROS production were completely inhibited by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), but were not affected by an NAD(P)H oxidase mutation, atrbohD atrbohF. Furthermore, the MG-elicited Ca²⁺ oscillations were significantly suppressed by SHAM but not by the atrbohD atrbohF mutation. Neither endogenous abscisic acid nor endogenous methyl jasmonate was involved in MG-induced stomatal closure. These results suggest that intrinsic metabolite MG can induce stomatal closure in Arabidopsis accompanied by extracellular ROS production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and Ca²⁺ oscillations.
甲基乙二醛 (MG) 是一种含氧的短醛和糖酵解中间体，在环境胁迫下在植物中积累。作为一种反应性的α-氧代醛，MG 可能在植物受到胁迫时作为一种信号分子发挥作用。我们研究了 MG 是否诱导气孔关闭、活性氧 (ROS) 产生和细胞质游离钙浓度 (Ca²⁺)，以阐明 MG 在拟南芥保卫细胞中的作用。MG 诱导 ROS 和 Ca²⁺ 振荡产生，导致气孔关闭。MG 诱导的气孔关闭和 ROS 产生被过氧化物酶抑制剂水杨基羟肟酸 (SHAM) 完全抑制，但不受 NAD(P)H 氧化酶突变 atrbohD atrbohF 的影响。此外，MG 诱导的 Ca²⁺ 振荡被 SHAM 显著抑制，但不受 atrbohD atrbohF 突变的影响。内源性脱落酸和内源性茉莉酸甲酯均不参与 MG 诱导的气孔关闭。这些结果表明，内源性代谢物 MG 可以诱导拟南芥的气孔关闭，同时伴有 SHAM 敏感过氧化物酶介导的细胞外 ROS 产生、细胞内 ROS 积累和 Ca²⁺ 振荡。
