The responses of three cultivars of Chinese cabbage (Brassica chmensis L.), one of the main vegetable crops in China, to different ratios of NH4+-N/NO3--N was investigated to find the optimal ratio of ammonium to nitr...The responses of three cultivars of Chinese cabbage (Brassica chmensis L.), one of the main vegetable crops in China, to different ratios of NH4+-N/NO3--N was investigated to find the optimal ratio of ammonium to nitrate for maximal growth and to explore ways of decreasing the nitrate content, increasing nitrogen use efficiency of Chinese cabbage, and determining distributions of nitrogen and carbon. Three cultivars of Chinese cabbage were hydroponically grown with three different NH4+-N/NO3--N ratios (0:10…展开更多
The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of mo...The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of molecules,including the natural auxin indole-3-acetic acid(IAA),as well as other phytoregulators.However,several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria.The effects of A.brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction.The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure,accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots.An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants.However,after five days of bacterization,the response disappeared in the primary root meristems.The role of polar auxin transport(PAT)in auxins relocation involved the PGP1,AXR4-1,and BEN2 proteins,which apparently mediated A.brasilense-induced root branching of Arabidopsis seedlings.展开更多
On the basis of two types of calcium transport system detected in the barley root plasma membrane,the mechanisms of the calcium transport have been further studied.Ionophore CCCP has been found to inhibit Mg^(2+) -dep...On the basis of two types of calcium transport system detected in the barley root plasma membrane,the mechanisms of the calcium transport have been further studied.Ionophore CCCP has been found to inhibit Mg^(2+) -dependent calcium transport by 20%.In contrast,Mg^(2+) -independent calcium trans- port is insensitive to CCCP.The Mg^(2+) -dependent calcium transport following the collapse of H^+ gradient across the plasma membrane could be driven by the H^+ gradient either set up by ATP or imposed artificially. Any relation between Mg^(2+) -independent calcium transport and H^+ gradient has not been observed.These results indicate that Mg^(2+) -dependent calcium transport is accompanied by the decrease of H^+ gradient,and Mg^(2+) -independent calcium transport has nothing to do with the H^+ gradient.It is therefore suggested that the calcium transport across the barley root plasma membrane is driven by ATPase that is independent of Mg^(2+),and H^+/Ca^(2+) antiporter that is dependent on Mg^(2+).展开更多
基金1 Project supported by the National Natural Science Foundation of China (No. 30270790).
文摘The responses of three cultivars of Chinese cabbage (Brassica chmensis L.), one of the main vegetable crops in China, to different ratios of NH4+-N/NO3--N was investigated to find the optimal ratio of ammonium to nitrate for maximal growth and to explore ways of decreasing the nitrate content, increasing nitrogen use efficiency of Chinese cabbage, and determining distributions of nitrogen and carbon. Three cultivars of Chinese cabbage were hydroponically grown with three different NH4+-N/NO3--N ratios (0:10…
基金supported by the Coordinación de la Investigación Científica UMSNH.E.C.-F.and J.A.-R.were fellows of CONACYT-México.
文摘The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of molecules,including the natural auxin indole-3-acetic acid(IAA),as well as other phytoregulators.However,several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria.The effects of A.brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction.The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure,accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots.An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants.However,after five days of bacterization,the response disappeared in the primary root meristems.The role of polar auxin transport(PAT)in auxins relocation involved the PGP1,AXR4-1,and BEN2 proteins,which apparently mediated A.brasilense-induced root branching of Arabidopsis seedlings.
文摘On the basis of two types of calcium transport system detected in the barley root plasma membrane,the mechanisms of the calcium transport have been further studied.Ionophore CCCP has been found to inhibit Mg^(2+) -dependent calcium transport by 20%.In contrast,Mg^(2+) -independent calcium trans- port is insensitive to CCCP.The Mg^(2+) -dependent calcium transport following the collapse of H^+ gradient across the plasma membrane could be driven by the H^+ gradient either set up by ATP or imposed artificially. Any relation between Mg^(2+) -independent calcium transport and H^+ gradient has not been observed.These results indicate that Mg^(2+) -dependent calcium transport is accompanied by the decrease of H^+ gradient,and Mg^(2+) -independent calcium transport has nothing to do with the H^+ gradient.It is therefore suggested that the calcium transport across the barley root plasma membrane is driven by ATPase that is independent of Mg^(2+),and H^+/Ca^(2+) antiporter that is dependent on Mg^(2+).
