Light and brassinosteroids (BRs) have been proved to be crucial in regulating plant growth and development, however, the mechanism of how they synergistically function is still largely unknown. To explore the underlying mechanisms in photomorphogenesis, genome-wide analyses were carried out through examining the gene expressions of the dark-grown WT or BR biosynthesis-defective mutant det2 seedlings in presence of light stimuli, or exogenous Brassinolide (BL). Results showed that BR deficiency stimulates, while BL treatment suppresses, the expressions of light responsive genes and photomorphogenesis, revealing the negative effects of BR in photomorphogenesis. This is consistent with that genes involved in cell wall modification and cellular metabolism were specifically modulated by BL during dark-light transition, and altered expressions of genes related to energy utilization. Further analysis revealed that hormone biosynthesis and signaling related genes, especially those of auxin, were altered under BL treatment or light stimuli, indicating that BR may modulate photomorphogenesis through synergetic regulation with other hormones. Additionally, suppressed ubiquitin-cycle pathway during light-dark transition hinted the presence of a complicated network among light, hormone and protein degradation. The study provides the direct evidence of BR effects in photomorphogenesis and identified the genes involved in BR and light signaling pathway, which will help to elucidate the molecular mechanism of plant photomorphogenesis.
Genome-wide analysis revealed the complex regulatory network of brassinosteroid effects in photomorphogenesis.
Age, Treatment
View SamplesHybrid weakness is a type of reproductive barrier found in many plant species and is important to plant evolution. Compared with heterosis, hybrid weakness has received less attention in evolutionary genetics studies. In rice, the hybrid weakness of the F1 progenies between the Jamaica- and temperate Japonica-types has been intensively genetically surveyed, and it has been found to be controlled by two complementary genes, Hwc1 and Hwc2. The defective development of the hybrid F1 seedlings was found to be mainly due to abnormal root growth, resulting in non-continuous growth and the eventual lethality of the plants. Detailed genome-wide analyses using the hybrid F1 plant and parents showed that, in contrast to heterosis, in which photosynthesis- and starch metabolism-related genes are preferentially expressed, the abscisic acid (ABA)-response and abiotic-/biotic- and defense-related genes were significantly up-regulated in the roots of the hybrid F1, resulting in suppressed growth of the whole plant. This indicates that the mechanisms of heterosis and hybrid weakness differ and provides informative clues to facilitate the understanding of the mechanisms controlling the reproductive isolation and hybrid weakness.
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Age, Specimen part
View SamplesThe angle of rice leaf inclination is an important agronomic trait and closely related to the yield and architecture of crops. Through genetic screening, a rice gain-of-function mutant leaf inclination1, lc1, was identified . Phenotypic analysis confirmed the exaggerated leaf angels of lc1 due to the stimulated cell elongation at the collar.In this series, we compare the transcriptome of zhonghua11 and lc1 collar.
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Specimen part
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