Vavasseur Alain, Raghavendra Agepati S
CEA/Cadarache-DSV-DEVM, Laboratoire des Echanges Membranaires et Signalisation, UMR 6191 CNRS-CEA-Aix-Marseille II. 13108 St Paul Lez-Durance Cedex, France.
New Phytol. 2005 Mar;165(3):665-82. doi: 10.1111/j.1469-8137.2004.01276.x.
In this review we concentrate on guard cell metabolism and CO2 sensing. Although a matter of some controversy, it is generally accepted that the Calvin cycle plays a minor role in stomatal movements. Recent data emphasise the importance of guard cell starch degradation and of carbon import from the guard cell apoplast in promoting and maintaining stomatal opening. Chloroplast maltose and glucose transporters appear to be crucial to the export of carbon from both guard and mesophyll cells. The way guard cells sense CO2 remains an unresolved question. However, a better understanding of the cellular events downstream from CO2 sensing is emerging. We now recognise that there are common as well as unique steps in abscisic acid (ABA) and CO2 signalling pathways. For example, while ABA and CO2 both trigger increases in cytoplasmic free calcium, unlike ABA, CO2 does not promote a cytoplasmic pH change. Future advances in this area are likely to result from the increased use of techniques and resources, such as, reverse genetics, novel mutants, confocal imaging, and microarray analyses of the guard cell transcriptome.
在本综述中，我们聚焦于保卫细胞代谢及二氧化碳感知。尽管存在一些争议，但人们普遍认为卡尔文循环在气孔运动中作用较小。近期数据强调了保卫细胞淀粉降解以及保卫细胞质外体碳输入在促进和维持气孔开放方面的重要性。叶绿体麦芽糖和葡萄糖转运蛋白似乎对碳从保卫细胞和叶肉细胞的输出至关重要。保卫细胞感知二氧化碳的方式仍是一个未解决的问题。然而，对二氧化碳感知下游细胞事件的更好理解正在浮现。我们现在认识到脱落酸（ABA）和二氧化碳信号通路既有共同步骤也有独特步骤。例如，虽然ABA和二氧化碳都能引发细胞质游离钙增加，但与ABA不同，二氧化碳不会促进细胞质pH变化。该领域未来的进展可能源于技术和资源使用的增加，如反向遗传学、新型突变体、共聚焦成像以及保卫细胞转录组的微阵列分析。
