Stimulation of the blue light phototropic receptor NPH1 causes a transient increase in cytosolic Ca2+
AUTOR(ES)
Baum, Gideon
FONTE
The National Academy of Sciences
RESUMO
Blue light regulates plant growth and development, and three photoreceptors, CRY1, CRY2, and NPH1, have been identified. The transduction pathways of these receptors are poorly understood. Transgenic plants containing aequorin have been used to dissect the involvement of these three receptors in the regulation of intracellular Ca2+. Pulses of blue light induce cytosolic Ca2+ transients lasting about 80 s in Arabidopsis and tobacco seedlings. Use of organelle-targeted aequorins shows that Ca2+ increases are limited to the cytoplasm. Blue light treatment of cry1, cry2, and nph1 mutants showed that NPH1, which regulates phototropism, is largely responsible for the Ca2+ transient. The spectral response of the Ca2+ transient is similar to that of phototropism, supporting NPH1 involvement. Furthermore, known interactions between red and blue light and between successive blue light pulses on phototropic sensitivity are mirrored in the blue light control of cytosolic Ca2+ in these seedlings. Our observations raise the possibility that physiological responses regulated by NPH1, such as phototropism, may be transduced through cytosolic Ca2+.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=23986Documentos Relacionados
- phot1 and phot2 mediate blue light-induced transient increases in cytosolic Ca2+ differently in Arabidopsis leaves
- Mutations in the NPH1 locus of Arabidopsis disrupt the perception of phototropic stimuli.
- Arabidopsis nph1 and npl1: Blue light receptors that mediate both phototropism and chloroplast relocation
- Sarcoplasmic reticulum Ca2+ content, L-type Ca2+ current and the Ca2+ transient in rat myocytes during beta-adrenergic stimulation.
- Monitoring of cytosolic free Ca2+ in C5a-stimulated neutrophils: loss of receptor-modulated Ca2+ stores and Ca2+ uptake in granule-free cytoplasts.