title: Melatonin-induced CBF/DREB1s are essential for diurnal change of disease resistance and CCA1 expression in Arabidopsis.
abstract: Melatonin (N-acetyl-5-methoxytryptamine) is an important regulator of circadian rhythms and immunity in animals. However, the diurnal changes of endogenous melatonin and melatonin-mediated diurnal change of downstream responses remain unclear in Arabidopsis. Using the publicly available microarray data, we found that the transcript levels of two melatonin synthesis genes (serotonin N-acetyltransferase (SNAT) and caffeate O-methyltransferase (COMT)) and endogenous melatonin level were regulated by diurnal cycles, with different magnitudes of change. Moreover, the transcripts of C-repeat-binding factors (CBFs)/Drought response element Binding 1 factors (DREB1s) were co-regulated by exogenous melatonin and diurnal changes, indicating the possible correlation among clock, endogenous melatonin level and AtCBFs expressions. Interestingly, diurnal change of plant immunity against Pst DC3000 and CIRCADIANCLOCK ASSOCIATED 1 (CCA1) expression were largely lost in AtCBFs knockdown line-amiR-1. Taken together, this study identifies the molecular pathway underlying the diurnal changes of immunity in Arabidopsis. Notably, the diurnal changes of endogenous melatonin may regulate corresponding changes of AtCBF/DREB1s expression and their underlying diurnal cycle of plant immunity and AtCCA1.
authors.affiliation: Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou 570228, China. Electronic address: haitaoshi@wbgcas.cn.
authors.forename: Haitao
authors.initials: H
authors.lastname: Shi
authors.affiliation: Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou 570228, China.
authors.forename: Yunxie
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou 570228, China. Electronic address: czhe@hainu.edu.cn.
authors.forename: Chaozu
authors.initials: C
authors.lastname: He
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D060467:Disease Resistance / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D008550:Melatonin / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C114425:CCA1 protein, Arabidopsis; C114578:DREB1A protein, Arabidopsis; D014157:Transcription Factors; D008550:Melatonin
keywords: Arabidopsis; CBF/DREB1s; CCA1; Diurnal change; Melatonin; Plant immunity