Cloning and characterization of an up-regulated GA 20-oxidase gene in hybrid maize  

作　　者：Jinkun Du Yingyin Yao Zhongfu Ni Qixin Sun 

机构地区：[1]Department of Plant Genetics ＆ Breeding and State Key Laboratory for Agrobiotechnology, Key Laboratory of Crop Genomics and Genetie Improvement, Ministry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100094, China

出　　处：《Progress in Natural Science:Materials International》2009年第2期161-166,共6页自然科学进展·国际材料（英文版）

基　　金：This work was supported by National Basic Research Program of China (2007CB109000);National Natural Science Foundation of China (30771324).

摘　　要：Previous studies revealed that GA content and metabolism are positively correlated with a faster shoot growth rate of hybrid, and recently, genes participating in both GA biosynthesis and GA response pathways were also found to be differentially expressed between wheat hybrid and its parental inbreds. In this study, an up-regulated GA 20-oxidase gene in a maize hybrid, designated ZmGA20, was cloned. ZmGA20 contains an open reading frame （ORF） encoding 391 amino acid residues. BLASTX searches in GenBank revealed that the ZmGA20 is homologous to the sequences of GA20ox proteins from different species, and analysis also indicated that ZmGA20 had typical features of GA 20-oxidase proteins, including a ＂LPWKET＂ sequence. Semi-quantitative RT-PCR analysis showed that ZmGA20 was expressed in different tissues and/or organs. The expression level of ZmGA20 in the hybrid was higher than that in two parents （in roots, leaves, stems and embryo, and ears）. The abundance of ZmGA20 transcript was equal to that of the highly expressed parents, which provided molecular evidence for the observed GA content heterosis in maize hybrids. 2008 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.Previous studies revealed that GA content and metabolism are positively correlated with a faster shoot growth rate of hybrid,and recently,genes participating in both GA biosynthesis and GA response pathways were also found to be differentially expressed between wheat hybrid and its parental inbreds. In this study,an up-regulated GA 20-oxidase gene in a maize hybrid,designated ZmGA20,was cloned. ZmGA20 contains an open reading frame (ORF) encoding 391 amino acid residues. BLASTX searches in GenBank revealed that the ZmGA20 is homologous to the sequences of GA20ox proteins from different species,and analysis also indicated that ZmGA20 had typical features of GA 20-oxidase proteins,including a "LPWKET" sequence. Semi-quantitative RT-PCR analysis showed that ZmGA20 was expressed in different tissues and/or organs. The expression level of ZmGA20 in the hybrid was higher than that in two parents (in roots,leaves,stems and embryo,and ears). The abundance of ZmGA20 transcript was equal to that of the highly expressed parents,which provided molecular evidence for the observed GA content heterosis in maize hybrids.

关 键 词：GA 20-oxidase Gene expression MAIZE HETEROSIS 

分 类 号：S513[农业科学—作物学]