Cytosolic calcium ([Ca2+]cyt) elevation activates plasma membrane anion channels in guard cells, which is required for stomatal closure. However, involvement of the anion channels in the [Ca2+]cyt elevation remains unclear. We investigated the involvement using Arabidopsis thaliana anion channel mutants, slac1-4 slah3-3 and slac1-4 almt12-1. Extracellular calcium induced stomatal closure in the wild-type plants but not in the anion channel mutant plants whereas extracellular calcium induced [Ca2+]cyt elevation both in the wild-type guard cells and in the mutant guard cells. The peak height and the number of the [Ca2+]cyt spike were lower and larger in the slac1-4 slah3-3 than in the wild type and the height and the number in the slac1-4 almt12-1 were much lower and much larger than in the wild type. These results suggest that the anion channels are involved in the regulation of [Ca2+]cyt elevation in guard cells.

中文翻译：

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通过保卫细胞中的质膜阴离子通道调节细胞溶质钙尖峰的频率和高度。

细胞溶质钙 ([Ca2+]cyt) 升高会激活保卫细胞中的质膜阴离子通道，这是气孔关闭所必需的。然而，阴离子通道参与[Ca2+]cyt 升高仍不清楚。我们使用拟南芥阴离子通道突变体 slac1-4 slah3-3 和 slac1-4 almt12-1 研究了参与。细胞外钙在野生型植物中诱导气孔关闭，但在阴离子通道突变植物中没有，而在野生型保卫细胞和突变型保卫细胞中，细胞外钙诱导[Ca2+]cyt升高。与野生型相比，slac1-4 slah3-3 的峰高和[Ca2+]cyt 峰的数量比野生型低得多，而slah3-3 的峰高和数量要低得多，而且数量多得多。比野生型。