Role of calcium in signal transduction of Commelina guard cells

Journal article

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.

Authors: Gilroy, S; Fricker, M; Read, N; Trewavas, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Society of Plant Biologists
• Journal: Plant Cell
• Volume: 3
• Issue: 4
• Pages: 333-344
• Publication date: 1991-04-01
• DOI: 10.1105/tpc.3.4.333
• EISSN: 1532-298X
• ISSN: 1040-4651
• Language: English