title: Heat shock-induced biphasic Ca(2+) signature and OsCaM1-1 nuclear localization mediate downstream signalling in acquisition of thermotolerance in rice (Oryza sativa L.).
abstract: We investigated heat shock (HS)-triggered Ca(2+) signalling transduced by a Ca(2+) sensor, calmodulin (CaM), linked to early transcriptome changes of HS-responsive genes in rice. We observed a biphasic [Ca(2+) ](cyt) signature in root cells that was distinct from that in epicotyl and leaf cells, which showed a monophasic response after HS. Treatment with Ca(2+) and A23187 generated an intense and sustained increase in [Ca(2+) ](cyt) in response to HS. Conversely, treatment with Ca(2+) chelator, L-type Ca(2+) channel blocker and CaM antagonist, but not intracellular Ca(2+) release inhibitor, strongly inhibited the increased [Ca(2+) ](cyt) . HS combined with Ca(2+) and A23187 accelerated the expression of OsCaM1-1 and sHSPC/N genes, which suggests that the HS-induced apoplastic Ca(2+) influx is responsible for the [Ca(2+) ](cyt) response and downstream HS signalling. In addition, the biphasic response of OsCaM1-1 in the nucleus followed the Ca(2+) signature, which may provide the information necessary to direct HS-related gene expression. Overexpression of OsCaM1-1 induced the expression of Ca(2+) /HS-related AtCBK3, AtPP7, AtHSF and AtHSP at a non-inducing temperature and enhanced intrinsic thermotolerance in transgenic Arabidopsis. Therefore, HS-triggered rapid increases in [Ca(2+) ](cyt) , together with OsCaM1-1 expression and its nuclear localization, are important in mediating downstream HS-related gene expression for the acquisition of thermotolerance in rice.
authors.affiliation: Institute of Plant Biology & Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Wu
authors.forename: Dan-Li
authors.initials: DL
authors.lastname: Luo
authors.forename: Florence
authors.initials: F
authors.lastname: Vignols
authors.forename: Tsung-Luo
authors.initials: TL
authors.lastname: Jinn
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002122:Calcium Chloride / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects / Q000235:genetics; D002147:Calmodulin / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D018869:Heat-Shock Response / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D059828:Plant Cells / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013696:Temperature
chemical_list: D002121:Calcium Channel Blockers; D002147:Calmodulin; D010940:Plant Proteins; D012333:RNA, Messenger; D000001:Calcimycin; D002122:Calcium Chloride; D002118:Calcium