Mao Hude, Yu Lijuan, Li Zhanjie, Liu Hui, Han Ran
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China.
College of Life Sciences, Northwest A&F University, Yangling, 712100, Shanxi, China.
Genetica. 2016 Apr;144(2):243-57. doi: 10.1007/s10709-016-9896-z. Epub 2016 Mar 15.
Homeodomain-leucine zipper (HD-Zip) transcription factors regulate developmental processes and stress responses in plants, and they vary widely in gene number and family structure. In this study, 55 predicted maize HD-Zip genes were systematically analyzed with respect to their phylogenetic relationships, molecular evolution, and gene expression in order to understand the functional diversification within the family. Phylogenetic analysis of HD-Zip proteins from Zea mays, Oryza sativa, Arabidopsis thaliana, Vitis vinifera, and Physcomitrella patens showed that they group into four classes. We inferred that the copy numbers of classes I and III genes were relatively conserved in all five species. The 55 maize HD-Zip genes are distributed randomly on the ten chromosomes, with 15 segmental duplication and 4 tandem duplication events, suggesting that segmental duplications were the major contributors in the expansion of the maize HD-Zip gene family. Expression analysis of the 55 maize HD-Zip genes in different tissues and drought conditions revealed differences in the expression levels and patterns between the four classes. Promoter analysis revealed that a number of stress response-, hormone response-, light response-, and development-related cis-acting elements were present in their promoters. Our results provide novel insights into the molecular evolution and gene expression within the HD-Zip gene family in maize, and provide a solid foundation for future functional study of the HD-Zip genes in maize.
同源异型域-亮氨酸拉链（HD-Zip）转录因子调控植物的发育过程和应激反应，并且它们在基因数量和家族结构上差异很大。在本研究中，对55个预测的玉米HD-Zip基因进行了系统分析，涉及它们的系统发育关系、分子进化和基因表达，以了解该家族内的功能多样化。对来自玉米、水稻、拟南芥、葡萄和小立碗藓的HD-Zip蛋白进行系统发育分析表明，它们分为四类。我们推断，I类和III类基因的拷贝数在所有五个物种中相对保守。55个玉米HD-Zip基因随机分布在十条染色体上，有15个片段重复和4个串联重复事件，这表明片段重复是玉米HD-Zip基因家族扩张的主要因素。对55个玉米HD-Zip基因在不同组织和干旱条件下的表达分析揭示了四类基因在表达水平和模式上的差异。启动子分析表明，它们的启动子中存在许多与应激反应、激素反应、光反应和发育相关的顺式作用元件。我们的结果为玉米HD-Zip基因家族的分子进化和基因表达提供了新的见解，并为未来玉米HD-Zip基因的功能研究奠定了坚实的基础。
