Project description:Light and temperature variations are inescapable in nature, providing many types of information and influencing development and physiology. PHOTOTROPIN (PHOT) blue light receptor-kinases play well-characterized roles in multiple processes in short time scales, but functions over days, weeks, or seasons have rarely been explored. Here we show that PHOT2 integrates blue light and low temperature signals to control leaf number at flowering. Plants lacking PHOT2 show delayed flowering, specifically when grown in low temperature. This effect is blocked by loss of NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3), and can be phenocopied by reduced blue light intensity, and by removal of CAMTA2. PHOT2 and CAMTA2 show non-additive genetic interactions, and a deep RNA-sequencing time course reveals highly overlapping phot2- and camta2-dependent effects on gene expression patterns across the day. Network-based co-expression analysis indicates system-level up-regulation of key growth modules in phot2 and camta2 mutants. Temperature- and genotype-dependent modulation of florigen-anti-florigen balance in phot2 and camta2 mutants is consistent with the phenotype. Together these data establish PHOT2 and NPH3 as a light-temperature coincidence detection module, operating with CAMTA2 as a downstream or parallel regulator of PHOT2-dependent gene expression.
Project description:Light and temperature variations are inescapable in nature, providing many types of information and influencing development and physiology. PHOTOTROPIN (PHOT) blue light receptor-kinases play well-characterized roles in multiple processes in short time scales, but functions over days, weeks, or seasons have rarely been explored. Here we show that PHOT2 integrates blue light and low temperature signals to control leaf number at flowering. Plants lacking PHOT2 show delayed flowering, specifically when grown in low temperature. This effect is blocked by loss of NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3), and can be phenocopied by reduced blue light intensity, and by removal of CAMTA2. PHOT2 and CAMTA2 show non-additive genetic interactions, and a deep RNA-sequencing time course reveals highly overlapping phot2- and camta2-dependent effects on gene expression patterns across the day. Network-based co-expression analysis indicates system-level up-regulation of key growth modules in phot2 and camta2 mutants. Temperature- and genotype-dependent modulation of florigen-anti-florigen balance in phot2 and camta2 mutants is consistent with the phenotype. Together these data establish PHOT2 and NPH3 as a light-temperature coincidence detection module, operating with CAMTA2 as a downstream or parallel regulator of PHOT2-dependent gene expression.
Project description:Flavonoid biosynthesis in grape berry skin is affected by environmental factors such as light and temperature. However, the components of the light-signaling and low-temperature-induced ABA signaling networks related to flavonoid accumulation in grape berry skin have not been fully elucidated. To clarify details of the possible light- and ABA-related signal transduction networks, we performed comprehensive transcriptome analysis using grape berries cultured under different light and temperature conditions. We identified 40 light-inducible genes, 55 low-temperature-inducible genes, and 34 genes induced by light plus low temperature.
Project description:Most organisms have an endogenous circadian clock that is synchronized to environmental signals such as light and temperature. Although circadian rhythms have been described in the nematode C. elegans at the behavioral level, these rhythms appear to be relatively non-robust. Moreover, in contrast to other animal models, no circadian transcriptional rhythms have been identified. Thus, whether this simple nematode contains a bona fide circadian clock remains an open question. We used microarray experiments to identify light- and temperature-regulated transcriptional rhythms in C. elegans, and show that subsets of these transcripts are regulated in a circadian manner. In addition, we find that light and temperature also globally drive the expression of many genes, indicating that C. elegans exhibits systemic responses to these stimuli.