Os-GIGANTEA Confers Robust Diurnal Rhythms on the Global Transcriptome of Rice in the Field    

Abstract

The circadian clock controls physiological traits such as flowering time, photosynthesis, and growth in plants under laboratory conditions. Under natural field conditions, however, little is known about the significance of the circadian clock in plants. By time-course transcriptome analyses of rice (Oryza sativa) leaves, using a newly isolated rice circadian clockrelated mutant carrying a null mutation in Os-GIGANTEA (Os-GI), we show here that Os-GI controlled 75% (false discovery rate = 0.05) of genes among 27,201 genes tested and was required for strong amplitudes and fine-tuning of the diurnal rhythm phases of global gene expression in the field. However, transcripts involved in primary metabolism were not greatly affected by osgi. Time-course metabolome analyses of leaves revealed no trends of change in primary metabolites in osgi plants, and net photosynthetic rates and grain yields were not affected. By contrast, some transcripts and metabolites in the phenylpropanoid metabolite pathway were consistently affected. Thus, net primary assimilation of rice was still robust in the face of such osgi mutation-related circadian clock defects in the field, unlike the case with defects caused by Arabidopsis thaliana toc1 and ztl mutations in the laboratory.

Natural diversity in daily rhythms of gene expression contributes to phenotypic variation

“…Temporal rhythms of expression control plant traits of ecological and agricultural importance (12)(13)(14)(15)(16), and understanding how precisely these rhythms vary and how this variation influences phenotypes has broad implications for plant biology.…”

Molecular Regulation of Flowering Time in Grasses

“…The plant circadian system consists of biochemical timing mechanisms that temporarily modulate the function of several signalling pathways to measures changes in day-length and promote suitable timing of flowering to maximize reproductive success [2,3,6,7,9,10,[13][14][15]21,24,26,28,29,31,36,38,41,42,46,48,49,[56][57][58][59][60][61][62][63][64][65][66]. The photoperiod response on flowering time varies among grasses.…”

Caracterização do relógio biológico e seu impacto no metabolismo da cana-de-açúcar

“…Componentes do loop central, as PRRs e componentes do loop noturno possuem ortólogos em espécies como milho (Khan et al, 2010), arroz (Murakami et al, 2007;Izawa et al, 2011), cevada (Calixto et al, 2015), trigo (Mizuno et al, 2012;Gawronsk et al, 2014), sorgo (Murphy et al, 2011) e cana-de-açúcar Endo et al (2014).…”

“…Por isso, é possível afirmar que buscar compreender o mecanismo de funcionamento do relógio biológico na cana-de-açúcar cultivada em seu ambiente natural, o campo, possa ter um impacto real no desenvolvimento de alternativas para o aumento da produtividade desta espécie. Além disso, estudos associando genes do relógio biológico a características associadas à produtividade foram publicados em outras espécies de gramíneas de interesse agroeconômico, caso do trigo (Beales et al, 2007), cevada Campoli et al, 2012;Calixto et al, 2015), sorgo (Murphy et al, 2011) e arroz (Izawa et al, 2002;Izawa et al, 2011;Koo et al, 2013).…”

“…Experimentos conduzidos em campo com arroz focados na análise do relógio biológico mostraram que o relógio biológico não 41 só é ativo, mas atua, de fato, conjuntamente com as variações ambientais (Izawa et al, 2011;Sato et al, 2011;Nagano et al, 2012). O padrão de expressão dos transcritos de arroz associados às vias reguladas pelo relógio biológico é bastante influenciado por componentes ambientais, como temperatura e luz solar (Nagano et al, 2012).…”