Role of Calcium in Signal Transduction of Commelina Guard Cells.

作者：Simon Gilroy, Mark D. Fricker, Nick D. Read, ANTHONY J. TREWAVAS · 发表于：The Plant Cell · 年份：1991 · DOI：10.1105/tpc.3.4.333 · 被引用次数：331 · 研究领域：Plant Stress Responses and Tolerance、Medicinal Plants and Neuroprotection、Allelopathy and phytotoxic interactions

The role of cytosolic Ca2+ in signal transduction in stomatal guard cells of Commelina communis was investigated using fluorescence ratio imaging and photometry. By changing extracellular K+, extracellular Ca2+, or treatment with Br-A23187, substantive increases in cytosolic Ca2+ to over 1 micromolar accompanied stomatal closure. The increase in Ca2+ was highest in the cytoplasm around the vacuole and the nucleus. Similar increases were observed when the cells were pretreated with ethyleneglycol-bis-(o-aminoethyl)tetraacetic acid or the channel blocker La3+, together with the closing stimuli. This suggests that a second messenger system operates between the plasma membrane and Ca2+-sequestering organelle(s). The endogenous growth regulator abscisic acid elevated cytosolic Ca2+ levels in a minority of cells investigated, even though stomatal closure always occurred. Ca2+-dependent and Ca2+-independent transduction pathways linking abscisic acid perception to stomatal closure are thus indicated.