The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature.Plasma membrane proteins,fatty acids and carotenoids profiles of Antarctic psychrophilc y...The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature.Plasma membrane proteins,fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp.NJ298 were investigated at-3 ℃,0 ℃ and 8 ℃.The results showed that plasma membrane protein content was greater at-3 ℃ than that at 8 ℃,and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis;GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids(C18:1 and C18:2) and shorter chain saturated fatty acid(C10:0) increased along with the decrease of the culture temperature from 8 ℃ to-3 ℃;HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane,percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at-3 ℃.However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at-3 ℃,0 ℃ and 8 ℃.Hence these changes in plasma membrane’s characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.展开更多
Rice(Oryza sativa L.),a thermophilic crop,is highly sensitive to cold stress,particularly during the seedling stage.Developing cold-tolerant rice varieties is a possible strategy to mitigate yield losses caused by low...Rice(Oryza sativa L.),a thermophilic crop,is highly sensitive to cold stress,particularly during the seedling stage.Developing cold-tolerant rice varieties is a possible strategy to mitigate yield losses caused by low temperatures.However,few genes for cold tolerance have been identified.In this study,we identified OsALA4(Aminophospholipid ATPase 4),encoding a plasma membrane-localized P4-ATPase,from a chromosomal segment substitution line(CSSL-K2832-2)harboring cold-tolerance QTL qLTS5(Low Temperature Sensitive 5).Genetic and subcellular localization analyses revealed that OsALA4 regulates cold tolerance by maintaining plasma membrane fluidity and cellular homeostasis.Physiological assessments showed that OsALA4 reduces malondialdehyde(MDA),electrolyte leakage,reactive oxygen species(ROS),and cell death under cold stress.Promoter activity assays indicated that stronger OsALA4 expression in Nipponbare(OsALA4Nip)correlated with enhanced cold tolerance.Further experiments demonstrated that SNP sites within the promoter regions(-1500 bp to-700 bp)of OsALA4Nipand OsALA49311influenced their activity.This study highlights Os ALA4 as a valuable genetic target for breeding cold tolerant rice.展开更多
文摘The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature.Plasma membrane proteins,fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp.NJ298 were investigated at-3 ℃,0 ℃ and 8 ℃.The results showed that plasma membrane protein content was greater at-3 ℃ than that at 8 ℃,and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis;GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids(C18:1 and C18:2) and shorter chain saturated fatty acid(C10:0) increased along with the decrease of the culture temperature from 8 ℃ to-3 ℃;HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane,percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at-3 ℃.However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at-3 ℃,0 ℃ and 8 ℃.Hence these changes in plasma membrane’s characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.
基金supported by grants from the National Natural Science Foundation of China(32121003,32325038)Key Research and Development Projects of Sichuan(2021YFYZ0016)Open Project Program(SKL-ZD202207)of State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China。
文摘Rice(Oryza sativa L.),a thermophilic crop,is highly sensitive to cold stress,particularly during the seedling stage.Developing cold-tolerant rice varieties is a possible strategy to mitigate yield losses caused by low temperatures.However,few genes for cold tolerance have been identified.In this study,we identified OsALA4(Aminophospholipid ATPase 4),encoding a plasma membrane-localized P4-ATPase,from a chromosomal segment substitution line(CSSL-K2832-2)harboring cold-tolerance QTL qLTS5(Low Temperature Sensitive 5).Genetic and subcellular localization analyses revealed that OsALA4 regulates cold tolerance by maintaining plasma membrane fluidity and cellular homeostasis.Physiological assessments showed that OsALA4 reduces malondialdehyde(MDA),electrolyte leakage,reactive oxygen species(ROS),and cell death under cold stress.Promoter activity assays indicated that stronger OsALA4 expression in Nipponbare(OsALA4Nip)correlated with enhanced cold tolerance.Further experiments demonstrated that SNP sites within the promoter regions(-1500 bp to-700 bp)of OsALA4Nipand OsALA49311influenced their activity.This study highlights Os ALA4 as a valuable genetic target for breeding cold tolerant rice.
