Blue Light and Phytochrome-Mediated Stomatal Opening in the npq1 and phot1 phot2 Mutants of Arabidopsis1
AUTOR(ES)
Talbott, Lawrence D.
FONTE
The American Society for Plant Biologists
RESUMO
Recent studies have shown that blue light-specific stomatal opening is reversed by green light and that far-red light can be used to probe phytochrome-dependent stomatal movements. Here, blue-green reversibility and far-red light were used to probe the stomatal responses of the npq1 mutant and the phot1 phot2 double mutant of Arabidopsis. In plants grown at 50 μmol m-2 s-1, red light (photosynthetic)-mediated opening in isolated stomata from wild type (WT) and both mutants saturated at 100 μmol m-2 s-1. Higher fluence rates caused stomatal closing, most likely due to photo-inhibition. Blue light-specific opening, probed by adding blue light (10 μmol m-2 s-1) to a 100 μmol m-2 s-1 red background, was found in WT, but not in npq1 or phot1 phot2 double mutant stomata. Under 50 μmol m-2 s-1 red light, 10 μmol m-2 s-1 blue light opened stomata in both WT and npq1 mutant stomata but not in the phot1 phot2 double mutant. In npq1, blue light-stimulated opening was reversed by far-red but not green light, indicating that npq1 has a phytochrome-mediated response and lacks a blue light-specific response. Stomata of the phot1 phot2 double mutant opened in response to 20 to 50 μmol m-2 s-1 blue light. This opening was green light reversible and far-red light insensitive, indicating that stomata of the phot1 phot2 double mutant have a detectable blue light-specific response.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=300709Documentos Relacionados
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