Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we rep...Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we report that T. salsuginea also shows greater heat tolerance than Arabidopsis. We identified T. salsuginea HsfAld （TsHsfAld） as a gene that can confer marked heat tolerance on Arabidopsis. TsHsfAld was identified via Full-length cDNA Over-eXpressing gene （FOX） hunt-ing from among a collection of heat-stress-related T. salsuginea cDNAs. Transgenic Arabidopsis overexpressing TsHsfAld showed constitutive up-regulation of many genes in the Arabidopsis AtHsfA1 regulon under normal growth tempera-ture. in Arabidopsis mesophyll protoplasts, TsHsfAld was localized in both the nucleus and the cytoplasm. TsHsfAld also interacted with AtHSP90, which negatively regulates AtHsfAls by forming HsfA1-HSP90 complexes in the cytoplasm. It is likely that the partial nuclear localization of TsHsfAld induced the expression of the AtHsfAld regulon in the transgenic plants at normal temperature. We also discovered that transgenic Arabidopsis plants overexpressing AtHsfAldwere more heat-tolerant than wild-type plants and up-regulated the expression of the HsfAld regulon, as was observed in TsHsfAld-overexpressing plants. We propose that the products of both TsHsfAld and AtHsfAld function as positive regulators of Arabidopsis heat-stress response and would be useful for the improvement of heat-stress tolerance in other plants.展开更多
Thermomorphogenesis and the heat shock(HS)response are distinct thermal responses in plants that are regulated by PHYTOCHROME-INTERACTING FACTOR 4(PIF4)and HEAT SHOCK FACTOR A1s(HSFA1s),respectively.Little is known ab...Thermomorphogenesis and the heat shock(HS)response are distinct thermal responses in plants that are regulated by PHYTOCHROME-INTERACTING FACTOR 4(PIF4)and HEAT SHOCK FACTOR A1s(HSFA1s),respectively.Little is known about whether these responses are interconnected and whether they are activated by similar mechanisms.An analysis of transcriptome dynamics in response to warm temperature(28℃)treatment revealed that 30 min of exposure activated the expression of a subset of HSFA1 target genes in Arabidopsis thaliana.Meanwhile,a loss-of-function HSFA1 quadruple mutant(hsfa1-cq)was insensitive to warm temperature-induced hypocotyl growth.In hsfa1-cq plants grown at 28℃,the protein and transcript levels of PIF4 were greatly reduced,and the circadian rhythm of many thermomorphogenesis-related genes(including PIF4)was disturbed.Additionally,the nuclear localization of HSFA1s and the binding of HSFA1d to the PIF4 promoter increased following warm temperature exposure,whereas PIF4 overexpression in hsfa1-cq partially rescued the altered warm temperature-induced hypocotyl growth of the mutant.Taken together,these results suggest that HSFA1s are required for PIF4 accumulation at a warm temperature,and they establish a central role for HSFA1s in regulating both thermomorphogenesis and HS responses in Arabidopsis.展开更多
High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlyi...High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlying mechanisms remain obscure.Here,we demonstrate that the glycogen synthase kinase 3(GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2(BIN2),a negative component in the BR signaling pathway,interacts with the master heat-responsive transcription factors CLASS A1 HEAT SHOCK TRANSCRIPTION FACTORS(HsfA1s).Furthermore,BIN2 phosphorylates HsfA1d on T263 and S56 to suppress its nuclear localization and inhibit its DNA-binding ability,respectively.BR signaling promotes plant thermotolerance by releasing the BIN2 suppression of HsfA1d to facilitate its nuclear localization and DNA binding.Our study provides insights into the molecular mechanisms by which BRs promote plant thermotolerance by strongly regulating HsfA1d through BIN2 and suggests potential ways to improve crop yield under extreme high temperatures.展开更多
文摘Thellungiella salsuginea （formerly T. halophila）, a species closely related to Arabidopsis （Arabidopsis thali-ana）, is tolerant not only to high salt levels, but also to chilling, freezing, and ozone. Here, we report that T. salsuginea also shows greater heat tolerance than Arabidopsis. We identified T. salsuginea HsfAld （TsHsfAld） as a gene that can confer marked heat tolerance on Arabidopsis. TsHsfAld was identified via Full-length cDNA Over-eXpressing gene （FOX） hunt-ing from among a collection of heat-stress-related T. salsuginea cDNAs. Transgenic Arabidopsis overexpressing TsHsfAld showed constitutive up-regulation of many genes in the Arabidopsis AtHsfA1 regulon under normal growth tempera-ture. in Arabidopsis mesophyll protoplasts, TsHsfAld was localized in both the nucleus and the cytoplasm. TsHsfAld also interacted with AtHSP90, which negatively regulates AtHsfAls by forming HsfA1-HSP90 complexes in the cytoplasm. It is likely that the partial nuclear localization of TsHsfAld induced the expression of the AtHsfAld regulon in the transgenic plants at normal temperature. We also discovered that transgenic Arabidopsis plants overexpressing AtHsfAldwere more heat-tolerant than wild-type plants and up-regulated the expression of the HsfAld regulon, as was observed in TsHsfAld-overexpressing plants. We propose that the products of both TsHsfAld and AtHsfAld function as positive regulators of Arabidopsis heat-stress response and would be useful for the improvement of heat-stress tolerance in other plants.
基金supported by grants from the National Natural Science Foundation of China(32070293)the Natural Science Foundation of Hebei Province(C2020205028,C2021205013,C2021205009)High-Level Talent Team Construction Project of Hebei Province(225A2902D).
文摘Thermomorphogenesis and the heat shock(HS)response are distinct thermal responses in plants that are regulated by PHYTOCHROME-INTERACTING FACTOR 4(PIF4)and HEAT SHOCK FACTOR A1s(HSFA1s),respectively.Little is known about whether these responses are interconnected and whether they are activated by similar mechanisms.An analysis of transcriptome dynamics in response to warm temperature(28℃)treatment revealed that 30 min of exposure activated the expression of a subset of HSFA1 target genes in Arabidopsis thaliana.Meanwhile,a loss-of-function HSFA1 quadruple mutant(hsfa1-cq)was insensitive to warm temperature-induced hypocotyl growth.In hsfa1-cq plants grown at 28℃,the protein and transcript levels of PIF4 were greatly reduced,and the circadian rhythm of many thermomorphogenesis-related genes(including PIF4)was disturbed.Additionally,the nuclear localization of HSFA1s and the binding of HSFA1d to the PIF4 promoter increased following warm temperature exposure,whereas PIF4 overexpression in hsfa1-cq partially rescued the altered warm temperature-induced hypocotyl growth of the mutant.Taken together,these results suggest that HSFA1s are required for PIF4 accumulation at a warm temperature,and they establish a central role for HSFA1s in regulating both thermomorphogenesis and HS responses in Arabidopsis.
基金supported by grant 31661143024 from the National Natural Science Foundation of China(to X.W.)grant 0120150092 from the Agricultural Research Outstanding Talents and Innovation Team of the Ministry of Agriculture(to X.W.).
文摘High temperature adversely affects plant growth and development.The steroid phytohormones brassinosteroids(BRs)are recognized to play important roles in plant heat stress responses and thermotolerance,but the underlying mechanisms remain obscure.Here,we demonstrate that the glycogen synthase kinase 3(GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2(BIN2),a negative component in the BR signaling pathway,interacts with the master heat-responsive transcription factors CLASS A1 HEAT SHOCK TRANSCRIPTION FACTORS(HsfA1s).Furthermore,BIN2 phosphorylates HsfA1d on T263 and S56 to suppress its nuclear localization and inhibit its DNA-binding ability,respectively.BR signaling promotes plant thermotolerance by releasing the BIN2 suppression of HsfA1d to facilitate its nuclear localization and DNA binding.Our study provides insights into the molecular mechanisms by which BRs promote plant thermotolerance by strongly regulating HsfA1d through BIN2 and suggests potential ways to improve crop yield under extreme high temperatures.
文摘以构建的表达拟南芥热激因子HsfA1 a C端氨基酸331到氨基酸486(简称ΔHsfA1 a)的大肠杆菌E coliM15为材料,用异丙基硫代-β-D-半乳糖苷(IPTG)诱导表达ΔHsfA1 a,再通过N i-NTA-Agarose亲和层析纯化表达的ΔHsfA1 a,通过SDS-PAGE电泳分析表达蛋白和纯化蛋白,获得了表达纯化的ΔHsfA1 a.
