Plants can sense the direction of gravity and orient their growth to ensure that roots are anchored in soil and that shoots grow upward. Gravitropism has been studied extensively using Arabidopsis genetics, but the ex...Plants can sense the direction of gravity and orient their growth to ensure that roots are anchored in soil and that shoots grow upward. Gravitropism has been studied extensively using Arabidopsis genetics, but the exact mecha- nisms for gravitropism are not fully understood. Here, we demonstrate that five NPY genes play a key role in Arabidopsis root gravitropism. NPYgenes were previously identified as regulators of auxin-mediated organogenesis in a genetic pathway with the AGC kinases PID, PID2, WAG1, and WAG2. We show that all five NPYgenes are highly expressed in primary root tips. The single npy mutants do not display obvious gravitropism defects, but the npyl npy2 npy3 npy4 npy5 quin- tuple mutants show dramatic gravitropic phenotypes. Systematic analysis of all the npy double, triple, and quadruple combinations demonstrates that the five NPY genes all contribute to gravitropism. Our work indicates that gravitropism, phototropism, and organogenesis use analogous mechanisms in which at least one AGC kinase, one NPH3/NPY gene, and one ARF are required.展开更多
A small solute has been obtained with column chromatography, which only exists and accumulates in the leaves of dune reed in northwest China’s desert region. Its unique polyamine and aromatic features are quite diffe...A small solute has been obtained with column chromatography, which only exists and accumulates in the leaves of dune reed in northwest China’s desert region. Its unique polyamine and aromatic features are quite different from those well-known ones accumulated under stresses. The natural quantity of the solute is strikingly proportional to the level of local high temperature, and a large section is distributed in the photosynthetic chloroplasts. Under lab conditions, we have proved that the solute plays a role in protecting or conserving chloroplasts under heat stress. So it is reasonable to suppose that the high resistance of dune reed to environmental high temperature and/or drought is at least partially due to the accumulation of this unique solute.展开更多
AGC protein kinases play important roles in plant growth and development.Several AGC kinases in Arabidopsis have been functionally characterized.However,the"AGC Other"subfamily,including IRE,IREH1,IRE3 and I...AGC protein kinases play important roles in plant growth and development.Several AGC kinases in Arabidopsis have been functionally characterized.However,the"AGC Other"subfamily,including IRE,IREH1,IRE3 and IRE4,has not been well understood.Here,we reported that ireh1 mutants displayed a root skewing phenotype,which can be enhanced by ire3 mutation.IREH1 and IRE3 were expressed in roots,consistent with their function in controlling root skewing.The fluorescence intensities of the microtubule marker KNpro:EGFP-MBD were decreased in ireh1,ire3 and ireh1 ire3 mutants compared to wild type.The microtubule arrangements in ireh1 and ireh1 ire3 mutants were also altered.IREH1 physically interacted with IRE3 in vitro and in planta.Thus,our findings demonstrate that IREH1 and IRE3 protein kinases play important roles in controlling root skewing,and maintaining microtubule network in Arabidopsis.展开更多
文摘Plants can sense the direction of gravity and orient their growth to ensure that roots are anchored in soil and that shoots grow upward. Gravitropism has been studied extensively using Arabidopsis genetics, but the exact mecha- nisms for gravitropism are not fully understood. Here, we demonstrate that five NPY genes play a key role in Arabidopsis root gravitropism. NPYgenes were previously identified as regulators of auxin-mediated organogenesis in a genetic pathway with the AGC kinases PID, PID2, WAG1, and WAG2. We show that all five NPYgenes are highly expressed in primary root tips. The single npy mutants do not display obvious gravitropism defects, but the npyl npy2 npy3 npy4 npy5 quin- tuple mutants show dramatic gravitropic phenotypes. Systematic analysis of all the npy double, triple, and quadruple combinations demonstrates that the five NPY genes all contribute to gravitropism. Our work indicates that gravitropism, phototropism, and organogenesis use analogous mechanisms in which at least one AGC kinase, one NPH3/NPY gene, and one ARF are required.
文摘A small solute has been obtained with column chromatography, which only exists and accumulates in the leaves of dune reed in northwest China’s desert region. Its unique polyamine and aromatic features are quite different from those well-known ones accumulated under stresses. The natural quantity of the solute is strikingly proportional to the level of local high temperature, and a large section is distributed in the photosynthetic chloroplasts. Under lab conditions, we have proved that the solute plays a role in protecting or conserving chloroplasts under heat stress. So it is reasonable to suppose that the high resistance of dune reed to environmental high temperature and/or drought is at least partially due to the accumulation of this unique solute.
基金supported by the grants from the National Natural Science Foundation of China (31270330, 91217310, 91017008 and 31171389)the National Basic Research Program of China (2014CB943400)+2 种基金the National Key Research and Development Program of China (2016YFD0100402)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA0801010402)the One-Hundred Talent Project of the Chinese Academy of Sciences to Y.C
文摘AGC protein kinases play important roles in plant growth and development.Several AGC kinases in Arabidopsis have been functionally characterized.However,the"AGC Other"subfamily,including IRE,IREH1,IRE3 and IRE4,has not been well understood.Here,we reported that ireh1 mutants displayed a root skewing phenotype,which can be enhanced by ire3 mutation.IREH1 and IRE3 were expressed in roots,consistent with their function in controlling root skewing.The fluorescence intensities of the microtubule marker KNpro:EGFP-MBD were decreased in ireh1,ire3 and ireh1 ire3 mutants compared to wild type.The microtubule arrangements in ireh1 and ireh1 ire3 mutants were also altered.IREH1 physically interacted with IRE3 in vitro and in planta.Thus,our findings demonstrate that IREH1 and IRE3 protein kinases play important roles in controlling root skewing,and maintaining microtubule network in Arabidopsis.
