Effects of chemical inhibitors and apyrase enzyme further document a role for apyrases and extracellular ATP in the opening and closing of stomates in Arabidopsis
Effects of chemical inhibitors and apyrase enzyme further document a role for apyrases and extracellular ATP in the opening and closing of stomates in Arabidopsis
复制标题
DOI：
10.4161/psb.26093
复制
发表时间：
2013-01-01
影响因子：
2.9
通讯作者：
Roux, Stanley
中科院分区：
文献类型：
--
作者：
Clark, Greg;Darwin, Cameron;Roux, Stanley
在拟南芥叶片中，对施加的核苷酸存在双相剂量-反应，即低浓度诱导气孔打开，而高浓度诱导关闭。哺乳动物的两种嘌呤受体拮抗剂PPADS和RB2可以阻断核苷酸诱导的气孔开放和关闭。这些拮抗剂还部分阻断了ABA诱导的气孔关闭和光诱导的气孔开放。拟南芥有两个密切相关的apyrase，AtAPY1和AtAPY2，它们都在保卫细胞中表达。在这里，我们报道了低水平的apyrase化学抑制剂可以在黑暗中诱导气孔开放，而apyrase酶则阻断ABA诱导的气孔关闭。我们还证明了高浓度的三磷酸腺苷在光照下诱导气孔关闭。在不影响气孔关闭的浓度下，应用AT、P、伽玛、S和化学APYRase抑制剂可以降低ABA诱导气孔关闭的阈值。在gpa1-3功能缺失突变体中，未观察到三磷酸腺苷γ-S诱导的关闭。这些结果进一步证实了细胞外ATP在调节气孔开度中的作用。
In Arabidopsis leaves there is a bi-phasic dose-response to applied nucleotides; i.e., lower concentrations induce stomatal opening, while higher concentrations induce closure. Two mammalian purinoceptor antagonists, PPADS and RB2, block both nucleotide-induced stomatal opening and closing. These antagonists also partially block ABA-induced stomatal closure and light-induced stomatal opening. There are two closely related Arabidopsis apyrases, AtAPY1 and AtAPY2, which are both expressed in guard cells. Here we report that low levels of apyrase chemical inhibitors can induce stomatal opening in the dark, while apyrase enzyme blocks ABA-induced stomatal closure. We also demonstrate that high concentrations of ATP induce stomatal closure in the light. Application of AT P gamma S and chemical apyrase inhibitors at concentrations that have no effect on stomatal closure can lower the threshold for ABA-induced closure. The closure induced by ATP gamma S was not observed in gpa1-3 loss-of-function mutants. These results further confirm the role of extracellular ATP in regulating stomatal apertures.