Intertissue Signal Transfer of Abscisic Acid from Vascular Cells to Guard Cells
Intertissue Signal Transfer of Abscisic Acid from Vascular Cells to Guard Cells
复制标题
DOI：
10.1104/pp.114.235556
复制
发表时间：
2014-04-01
期刊：
影响因子：
7.4
通讯作者：
Shinozaki, Kazuo
中科院分区：
文献类型：
--
作者：
Kuromori, Takashi;Sugimoto, Eriko;Shinozaki, Kazuo
脱落酸(ABA)是一种对环境胁迫(如缺水)做出反应的植物激素。最近的研究表明，ABA生物合成酶在非胁迫和水分胁迫生长条件下的维管区都有表达。然而，参与ABA生物合成的维管系统中的特定细胞尚未被鉴定。在这里，我们检测了两个编码ABA生物合成酶的基因在维管组织的韧皮部伴生细胞中的表达，即脱落酸脱氢酶2和脱落酸脱氢酶3。此外，我们还鉴定了一个三磷酸腺苷结合盒转运蛋白，拟南芥ABCG25(AtABCG25)，在相同的细胞中表达。此外，表达ATABCG25的果蝇培养细胞具有ABA外排功能。最后，我们观察到，即使在正常生长条件下，韧皮部伴生细胞中ABA生物合成的增强也会引发保卫细胞反应。这些结果表明，ABA是在特定的细胞中合成的，并可以转运到不同组织中的靶细胞。
Abscisic acid (ABA) is a phytohormone that responds to environmental stresses, such as water deficiency. Recent studies have shown that ABA biosynthetic enzymes are expressed in the vascular area under both nonstressed and water-stressed growth conditions. However, specific cells in the vasculature involved in ABA biosynthesis have not been identified. Here, we detected the expression of two genes encoding ABA biosynthetic enzymes, ABSCISIC ACID DEFICIENT2 and ABSCISIC ALDEHYDE OXIDASE3, in phloem companion cells in vascular tissues. Furthermore, we identified an ATP-binding cassette transporter, Arabidopsis thaliana ABCG25 (AtABCG25), expressed in the same cells. Additionally, AtABCG25-expressing Spodoptera frugiperda9 culture cells showed an ABA efflux function. Finally, we observed that enhancement of ABA biosynthesis in phloem companion cells induced guard cell responses, even under normal growth conditions. These results show that ABA is synthesized in specific cells and can be transported to target cells in different tissues.