中文摘要：

在本实验室前期研究的干旱胁迫相关的抑制差减文库（SSH）中,发现一个玉米干旱胁迫诱导表达的EST序列,与拟南芥AtCKS2和AtCKS1基因有较高的同源性。应用生物信息学手段和同源克隆的方法,分离得到该基因,命名为ZmCKS2。序列分析表明该基因开放阅读框区267bp,编码88个氨基酸。ZmCKS2蛋白含有真核生物中高度保守的CKS（cyclin-dependent kinase regulatory subunit）结构域。应用在线分析软件预测该基因上游2kb序列表明,该序列具有启动子的核心序列和增强子序列,同时还具有与干旱等多种逆境胁迫相关的调控序列。应用实时荧光定量PCR分析表明该基因在幼穗中表达量最高,且受干旱和MeJA诱导上调表达,受低温和外源ABA诱导下调表达。

英文摘要：

Plants respond to abiotic and biotic stresses through a number of biochemical and physiological reactions.Stresses inducible genes can be classified into two groups,i.e.functional genes that directly protect against stresses and regulator genes that regulate gene expression and signal transduction in the stress response.In our previous study,an EST from a drought related SSH（suppression subtractive hybridization） library was obtained,which had a high similarity to AtCKS2 in Arabidopsis.In the present study we cloned the cDNA homologous to CKS2,named ZmCKS2,using in silico and homology-based cloning techniques.ZmCKS2 had an ORF of 267 bp and encoded 88 amino acids.The deduced protein of ZmCKS2 was predicted to contain a CKS（cyclin-dependent kinase regulatory subunit） structural domain,which was highly conserved in eukaryotes kingdom.The promoter of ZmCKS2（about 2 kb upstream of ZmCKS2） was predicted to contain important regulatory elements including core promoter elements and drought,high salt,coldness,ABA,light regulation,copper,and oxygen responsive elements.Real-time quantitative PCR（qRT-PCR） analysis revealed that ZmCKS2 had different expression patterns in different organs.It was highly expressed in ears while its expression was very low in roots and leaves at seedling stage.qRT-PCR was also performed to investigate the expression profiles of the ZmCKS2 under different abiotic stresses such as drought,low temperature,high salt,MeJA（methyl jasmonate）,and exogenous ABA（abscisic acid）.Under drought or MeJA treatment,ZmCKS2 showed an up-regulated expression pattern.However,under cold or ABA treatment,this gene showed a down-regulation expression pattern.Under NaCl stress ZmCKS2 showed no obvious change.These results revealed that ZmCKS2 might be involved in multiple pathways of plants responding to different environmental conditions.