title: Melatonin induces class A1 heat-shock factors (HSFA1s) and their possible involvement of thermotolerance in Arabidopsis.
abstract: Melatonin (N-acetyl-5-methoxytryptamine) serves as an important signal molecule during plant developmental processes and multiple abiotic stress responses. However, the involvement of melatonin in thermotolerance and the underlying molecular mechanism in Arabidopsis were largely unknown. In this study, we found that the endogenous melatonin level in Arabidopsis leaves was significantly induced by heat stress treatment, and exogenous melatonin treatment conferred improved thermotolerance in Arabidopsis. The transcript levels of class A1 heat-shock factors (HSFA1s), which serve as the master regulators of heat stress responses, were significantly upregulated by heat stress and exogenous melatonin treatment in Arabidopsis. Notably, exogenous melatonin-enhanced thermotolerance was largely alleviated in HSFA1s quadruple knockout (QK) mutants, and HSFA1s-activated transcripts of heat-responsive genes (HSFA2, heat stress-associated 32 (HSA32), heat-shock protein 90 (HSP90), and 101 (HSP101)) might be contributed to melatonin-mediated thermotolerance. Taken together, this study provided direct link between melatonin and thermotolerance and indicated the involvement of HSFA1s-activated heat-responsive genes in melatonin-mediated thermotolerance in Arabidopsis.
authors.affiliation: Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou, China; Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Shi
authors.forename: Dun-Xian
authors.initials: DX
authors.lastname: Tan
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: Tiantian
authors.initials: T
authors.lastname: Ye
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Zhulong
authors.initials: Z
authors.lastname: Chan
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response / Q000187:drug effects*; D008550:Melatonin / Q000494:pharmacology*
chemical_list: D029681:Arabidopsis Proteins; D006360:Heat-Shock Proteins; D008550:Melatonin
keywords: Arabidopsis; class A1 heat-shock factors (HSFA1s); heat-responsive genes; melatonin; thermotolerance