巨桉C2H2锌指蛋白基因家族EgrZFP-EARs鉴定及其在非生物逆境下的表达模式分析OA北大核心CSTPCD

Eucalyptus spp.are widely planted in south of China as a fast-growing timber species.However,the resistance to abiotic stresses such as low temperature,drought,and salinity of them is very poor.Zinc finger protein(ZPF)transcription factor members containing the ethylene-responsive element binding factor-associated amphiphilic repression(EAR)motif have been shown to be extensively involved in plant responses to abiotic stresses such as cold,high temperature,drought and salinity.Based on the genome-wide identification of Eucalyptus grandis C2H2-type ZFP,the EgrZFP-EAR genes with EAR motif was screened.The evolutionary relationships of EgrZFP-EAR,the types,numbers and distributions of EAR motifs in their proteins,chromosome localization and gene replication of them,as well as gene and protein sequence structure and the cis-elements on their promoters were analyzed.In addition,transcriptome data and qRT-PCR were used to analyze the expression patterns of EgrZFP-EAR in different tissues and 4℃,high temperature(42℃),drought,NaCl(300 mmol/L),ABA(100 μmol/L)and MeJA(100 μmol/L)treatments of E.grandis seedlings.The results showed that there were 118 C2H2-type ZFP in E.grandis,57 of which were EgrZFP-EAR members,and 54 of these members encoded ZFP proteins containing Q-type sequence(QALGGH).They contained 3 types of EAR motifs:LxLxL,DLNx(x)p,and their overlap.The LxLxL type had the largest number of them,with a total of 98.Evolutionarily,genome-wide replication,tandem duplication and segment duplication all played roles in the expansion of these genes.Stress responsive elements such as DRE,MBS,LTR and STRE,and hormone responsive elements including ABRE and CGTCA-motif were distributed on the EgrZFP-EAR promoters.Tissue expression patterns were divided into 4 types:high expression in shoot tips and young leaves;high expression in phloem;high expression in mature xylem;and high expression in phloem,immature and mature xylem.The expression patterns of EgrZFP-EAR gene in leaves of E.grandis seedlings treated with 4℃for different time(2,6,12,24,48 h)were classified into 3 types.Genes in the first type were induced persistently;the expression of genes in the second type ascended firstly and then descended;and in the third type,genes'expression was mainly inhibited.The selected 12 genes from different EgrZFP-EAR subgroup were also responsive differently to high temperature,drought,NaCl,ABA and MeJA treatments,implicating the complex function of EgrZFP-EAR gene under abiotic stresses.The results provide an foundation for further revealing the molecular mechanism of stress resistance,the exploitation of stress-resistant gene resources and molecular-assisted stress resistance breeding of Eucalyptus.