Salinity tissue tolerance is a key trait that confers adaptive potential in halophytic species.The aim of this study was to understand the mechanistic basis of salinity tissue tolerance in the Oryza coarctata,a haloph...Salinity tissue tolerance is a key trait that confers adaptive potential in halophytic species.The aim of this study was to understand the mechanistic basis of salinity tissue tolerance in the Oryza coarctata,a halophytic wild relative of cultivated rice Oryza sativa,to be then used as novel targets for improving salinity stress tolerance of O.sativa.Salinity led to ~80% decline in mesophyll cell viability in cultivated rice,whereas only 15% reduction was observed in the wild rice.In response to NaCl treatments,mesophyll cells of O.coarctata showed less Na^(+) uptake and better K^(+) retention than cultivated rice.Pharmacological experiments suggested that salinity-induced Na^(+) uptake and K^(+) loss in O.coarctata were mediated by non-selective cation channels(NSCCs) while K^(+) loss in cultivated rice was mediated predominantly by GORK(guard cell outward-rectifying K^(+)) channels.Salt treatment resulted in a depolarization of the plasma membrane(PM) in O.sativa.In contrast,O.coarctata had NaCl dose-dependent hyperpolarization in the mesophyll cells,due to its higher preference for Cl^(-)uptake.This difference in plant ionic relations was partially attributable to differences in transcriptional expression levels of Potassium transporter 1(AKT1),Salt overly sensitive 1(SOS1),Sodium transporter OsHKT1;4,and Chloride channel(OsCLC1).It is concluded that O.coarctata possesses a strong ability to discriminate between Cl^(-)and Na^(+) uptake(a trait lacking in cultivated rice) and use it to maintain negative membrane potential(MP) values without activating H^(+)-ATPase,thus enabling more efficient K^(+) retention in mesophyll with low energy costs.The above traits should be considered as potential targets in the rice breeding program for salt tolerance enhancement.展开更多
Salinity stress is a major environmental stress affecting crop productivity,and its negative impact on global food security is only going to increase,due to current climate trends.Salinity tolerance was present in wil...Salinity stress is a major environmental stress affecting crop productivity,and its negative impact on global food security is only going to increase,due to current climate trends.Salinity tolerance was present in wild crop relatives but significantly weakened during domestication.Regaining it back requires a good understanding of molecular mechanisms and traits involved in control of plant ionic and ROS homeostasis.This review summarizes our current knowledge on the role of major plant hormones(auxin,cytokinins,abscisic acid,salicylic acid,and jasmonate)in plants adaptation to soil salinity.We firstly discuss the role of hormones in controlling root tropisms,root growth and architecture(primary root elongation,meristematic activity,lateral root development,and root hairs formation).Hormone-mediated control of uptake and sequestration of key inorganic ions(sodium,potassium,and calcium)is then discussed followed by regulation of cell redox balance and ROS signaling in salt-stressed roots.Finally,the role of epigenetic alterations such as DNA methylation and histone modifications in control of plant ion and ROS homeostasis and signaling is discussed.This data may help develop novel strategies for breeding and cultivating salt-tolerant crops and improving agricultural productivity in saline regions.展开更多
基金supported by the Australian Department of Industry, Innovation and Science (Project AISRF48490) grantIndo-Australian Biotechnology Fund (BT/Indo-Aus/09/03/2015) provided by the Department of Biotechnology, Government of India。
文摘Salinity tissue tolerance is a key trait that confers adaptive potential in halophytic species.The aim of this study was to understand the mechanistic basis of salinity tissue tolerance in the Oryza coarctata,a halophytic wild relative of cultivated rice Oryza sativa,to be then used as novel targets for improving salinity stress tolerance of O.sativa.Salinity led to ~80% decline in mesophyll cell viability in cultivated rice,whereas only 15% reduction was observed in the wild rice.In response to NaCl treatments,mesophyll cells of O.coarctata showed less Na^(+) uptake and better K^(+) retention than cultivated rice.Pharmacological experiments suggested that salinity-induced Na^(+) uptake and K^(+) loss in O.coarctata were mediated by non-selective cation channels(NSCCs) while K^(+) loss in cultivated rice was mediated predominantly by GORK(guard cell outward-rectifying K^(+)) channels.Salt treatment resulted in a depolarization of the plasma membrane(PM) in O.sativa.In contrast,O.coarctata had NaCl dose-dependent hyperpolarization in the mesophyll cells,due to its higher preference for Cl^(-)uptake.This difference in plant ionic relations was partially attributable to differences in transcriptional expression levels of Potassium transporter 1(AKT1),Salt overly sensitive 1(SOS1),Sodium transporter OsHKT1;4,and Chloride channel(OsCLC1).It is concluded that O.coarctata possesses a strong ability to discriminate between Cl^(-)and Na^(+) uptake(a trait lacking in cultivated rice) and use it to maintain negative membrane potential(MP) values without activating H^(+)-ATPase,thus enabling more efficient K^(+) retention in mesophyll with low energy costs.The above traits should be considered as potential targets in the rice breeding program for salt tolerance enhancement.
基金supported by Australian Research Council and National Natural Science Foundation of China grants to Sergey Shabala。
文摘Salinity stress is a major environmental stress affecting crop productivity,and its negative impact on global food security is only going to increase,due to current climate trends.Salinity tolerance was present in wild crop relatives but significantly weakened during domestication.Regaining it back requires a good understanding of molecular mechanisms and traits involved in control of plant ionic and ROS homeostasis.This review summarizes our current knowledge on the role of major plant hormones(auxin,cytokinins,abscisic acid,salicylic acid,and jasmonate)in plants adaptation to soil salinity.We firstly discuss the role of hormones in controlling root tropisms,root growth and architecture(primary root elongation,meristematic activity,lateral root development,and root hairs formation).Hormone-mediated control of uptake and sequestration of key inorganic ions(sodium,potassium,and calcium)is then discussed followed by regulation of cell redox balance and ROS signaling in salt-stressed roots.Finally,the role of epigenetic alterations such as DNA methylation and histone modifications in control of plant ion and ROS homeostasis and signaling is discussed.This data may help develop novel strategies for breeding and cultivating salt-tolerant crops and improving agricultural productivity in saline regions.
