玉米ZmNAC99基因的克隆及干旱诱导表达分析

Isolation and Drought Induced Expression Characterization of ZmNAC99 Gene from Maize

以不同抗旱性玉米自交系为材料,克隆得到玉米ZmNAC99基因的gDNA序列和cDNA序列,并对其进行了初步的生物信息学分析,同时结合RT-PCR和qRT-PCR技术对其在不同干旱程度下的表达模式进行了分析。结果显示:(1)ZmNAC99基因的gDNA长1 892~1 908bp,cDNA长1 188bp,共编码395个氨基酸,其N-端具有保守的NAM结构域;系统进化分析表明推断的ZmNAC99蛋白属于NAC家族中的OsNAC3亚类。(2)RT-PCR和qRT-PCR分析表明,干旱胁迫诱导下ZmNAC99表达上调;顺式元件分析进一步揭示了ZmNAC99基因的推断启动子包含2个干旱应答顺式元件MBS和1个低温应答元件LTR。(3)不同抗旱性玉米自交系来源的ZmNAC99推断氨基酸序列存在4个氨基酸突变,推测其结构差异对玉米抗旱性可能产生一定影响。研究表明,ZmNAC99可能在植物的抗逆过程发挥作用。

The gDNA sequence and cDNA sequence of the ZmNAC99 gene were cloned from maize（Zea mays）inbred lines with differentially drought resistance.We carried on the preliminary bioinformatics analysis,and RT-PCR and qRT-PCR techniques were used to analyze the gene expression patterns under drought stress.The results indicated that：（1）the gDNA of ZmNAC99 were 1 892~1 908 bp and cDNA was 1 188 bp,encoding 395 amino acids,the N-terminal of ZmNAC99 has a typical NAM domain.Phylogenetic analysis showed that ZmNAC99 belonged to the OsNAC3 subfamily of the NAC family;（2）RTPCR and qRT-PCR analysis indicated that ZmNAC99 could be induced by drought stress treatment;The cis-element analysis further revealed that the putative promoter of the ZmNAC99 gene contained 2drought-responsive cis-elements MBS and 1low temperature responsive element LTR.（3）The amino acid sequence alignment analysis of ZmNAC99 from different drought-resistant maize inbred lines suggested that there were 4amino-acid mutation,and we speculated that the difference of the structure may have aneffect on the drought resistance of maize.These results suggest that ZmNAC99 may play an important role in the plant＇s resistance to stress.