Extracellular malate induces stomatal closure via direct
activation of guard-cell anion channel SLAC1 and stimulation
of Ca2+ signalling

编号 040036205

推送时间 20220926

研究领域 森林培育 

年份 2022 

类型 期刊 

语种 英语

标题 Extracellular malate induces stomatal closure via direct
activation of guard-cell anion channel SLAC1 and stimulation
of Ca2+ signalling

来源期刊 New Phytologist

期 第362期

发表时间 20220725

关键词 Arabidopsis;  Ca2+ signalling;  malate;  SLAC1;  stomata.; 

摘要 Plants secrete malate from guard cells to apoplast under stress conditions and exogenous
malate induces stomatal closure. Malate is considered an extracellular chemical signal of stomatal
closure. However, the molecular mechanism of malate-induced stomatal closure is not
fully elucidated.
We investigated responses of stomatal aperture, ion channels, and cytosolic Ca2+ to malate.
A treatment with malate induced stomatal closure in Arabidopsis thaliana wild-type plants,
but not in the mutants deficient in the slow (S-type) anion channel gene SLOW ANION
CHANNEL-ASSOCIATED 1 (SLAC1). The treatment with malate increased S-type anion currents
in guard-cell protoplasts of wild-type plants but not in the slac1 mutant. In addition,
extracellular rather than intracellular application of malate increased the S-type currents of
constitutively active mutants of SLAC1, which have kinase-independent activities, in a
heterologous expression system using Xenopus oocytes. The treatment with malate transiently
increased cytosolic Ca2+ concentration in the wild-type Arabidopsis guard cells and the
malate-induced stomatal closure was inhibited by the Ca2+ channel blocker and the Ca2+
chelator.
These results indicate that extracellular malate directly activates SLAC1 and simultaneously
stimulates Ca2+ signalling in guard cells, resulting in steady and solid activation of SLAC1 for
stomatal closure.

服务人员 孙小满

服务院士 尹伟伦

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