Plant metabolomics developed as a powerful tool to examine gene functions and to gain deeper insight into the physiology of the plant cell. In this study, we screened Arabidopsis lines overexpressing rice full-length ...Plant metabolomics developed as a powerful tool to examine gene functions and to gain deeper insight into the physiology of the plant cell. In this study, we screened Arabidopsis lines overexpressing rice full-length （FL） cDNAs （rice FOX Arabidopsis lines） using a gas chromatography-time-of-flight mass spectrometry （GC-TOF/MS）-based technique to identify rice genes that caused metabolic changes. This screening system allows fast and reliable identification of candi- date lines showing altered metabolite profiles. We performed metabolomic and transcriptomic analysis of a rice FOX Ara- bidopsis line that harbored the FL cDNA of the rice ortholog of the Lateral Organ Boundaries （LOB） Domain （LBD）/ Asymmetric Leaves2-1ike （ASL） gene of Arabidopsis, At-LBD37/ASL39. The investigated rice FOX Arabidopsis line showed prominent changes in the levels of metabolites related to nitrogen metabolism. The transcriptomic data as well as the results from the metabolite analysis of the Arabidopsis At-LBD37/ASL39-overexpressor plants were consistent with these findings. Furthermore, the metabolomic and transcriptomic analysis of the Os-LBD37/ASL39-overexpressing rice plants indicated that Os-LBD37/ASL39 is associated with processes related to nitrogen metabolism in rice. Thus, the combination of a metabolomics-based screening method and a gain-of-function approach is useful for rapid characterization of novel genes in both Arabidopsis and rice.展开更多
It is poorly understood how plants control their growth by cell division, elongation, and differentiation. We have characterized a seedling-lethal mutant segregation distortion 3 （sd3） that showed a very dwarf pheno...It is poorly understood how plants control their growth by cell division, elongation, and differentiation. We have characterized a seedling-lethal mutant segregation distortion 3 （sd3） that showed a very dwarf phenotype when grown in the light and, in the dark, had short hypocotyls with reduced ploidy levels. The corresponding gene of SD3 encodes a protein with high similarity to yeast translocase on the inner mitochondrial membrane 21 （TIM21）, which is a component of the TIM23 complex. Indeed, SD3 protein fused to GFP localized in the mitochondria. SD3 overexpression increased cotyledon size in the light and hypocotyl thickness in the dark. The expression of genes for several subunits of the respiratory-chain complexes III and IV was up-regulated in SD3-overexpressing plants. Furthermore, these plants showed high levels of ATP whereas those of sd3 were low. These results suggested that SD3 induced an increase in cell size by raising the expression of the respiratory-chain subunit genes and hence increased the intracellular ATP levels, We propose that intracellular ATP levels regulated by mitochondria control plant organ size.展开更多
文摘Plant metabolomics developed as a powerful tool to examine gene functions and to gain deeper insight into the physiology of the plant cell. In this study, we screened Arabidopsis lines overexpressing rice full-length （FL） cDNAs （rice FOX Arabidopsis lines） using a gas chromatography-time-of-flight mass spectrometry （GC-TOF/MS）-based technique to identify rice genes that caused metabolic changes. This screening system allows fast and reliable identification of candi- date lines showing altered metabolite profiles. We performed metabolomic and transcriptomic analysis of a rice FOX Ara- bidopsis line that harbored the FL cDNA of the rice ortholog of the Lateral Organ Boundaries （LOB） Domain （LBD）/ Asymmetric Leaves2-1ike （ASL） gene of Arabidopsis, At-LBD37/ASL39. The investigated rice FOX Arabidopsis line showed prominent changes in the levels of metabolites related to nitrogen metabolism. The transcriptomic data as well as the results from the metabolite analysis of the Arabidopsis At-LBD37/ASL39-overexpressor plants were consistent with these findings. Furthermore, the metabolomic and transcriptomic analysis of the Os-LBD37/ASL39-overexpressing rice plants indicated that Os-LBD37/ASL39 is associated with processes related to nitrogen metabolism in rice. Thus, the combination of a metabolomics-based screening method and a gain-of-function approach is useful for rapid characterization of novel genes in both Arabidopsis and rice.
文摘It is poorly understood how plants control their growth by cell division, elongation, and differentiation. We have characterized a seedling-lethal mutant segregation distortion 3 （sd3） that showed a very dwarf phenotype when grown in the light and, in the dark, had short hypocotyls with reduced ploidy levels. The corresponding gene of SD3 encodes a protein with high similarity to yeast translocase on the inner mitochondrial membrane 21 （TIM21）, which is a component of the TIM23 complex. Indeed, SD3 protein fused to GFP localized in the mitochondria. SD3 overexpression increased cotyledon size in the light and hypocotyl thickness in the dark. The expression of genes for several subunits of the respiratory-chain complexes III and IV was up-regulated in SD3-overexpressing plants. Furthermore, these plants showed high levels of ATP whereas those of sd3 were low. These results suggested that SD3 induced an increase in cell size by raising the expression of the respiratory-chain subunit genes and hence increased the intracellular ATP levels, We propose that intracellular ATP levels regulated by mitochondria control plant organ size.
