摘要
【目的】研究苹果枝条节间长度与内源激素赤霉素(GA)水平及GA合成关键酶基因序列和表达之间的关系,为进一步探索苹果短枝型芽变形成机理及选育新的短枝型苹果品种奠定基础。【方法】以‘长富2号’苹果及其短枝型芽变‘龙富短枝’的枝条和叶片为试材,通过对花后4个时期GA含量的测定及GA合成途径中关键基因的克隆及表达,研究枝条生长过程中GA与枝条节间长度的关系。【结果】在花后80 d,GA含量在非短枝型苹果及其短枝型芽变中差异显著,短枝型芽变品种中GA含量低于非短枝型品种。序列分析表明,GA合成关键酶基因GA20-氧化酶(GA20ox)和贝壳杉烯氧化酶(KO)的cDNA序列在‘龙富短枝’和‘长富2号’中完全一致,无碱基的突变、插入或缺失现象发生。实时荧光定量PCR分析表明,在花后20 d和80 d,GA20ox和KO的相对表达量在‘龙富短枝’和‘长富2号’之间差异显著,短枝型芽变品种中的相对表达量显著低于非短枝型苹果。【结论】GA含量差异和GA合成关键酶基因差异表达与短枝型苹果枝条节间长度相关联,低GA含量和GA合成关键酶基因的下调表达抑制了苹果枝条的伸长。
[ Objective ] The relationship between internode length of shoots, endogenous hormones gibberellic acid （GA） and the structure and expression of genes related to GA synthesis in apple （Malus domestica Borkh.） is a basis for further exploration of the spur type development mechanism and breeding of cultivars of spur type apple. [ Method ] The shoots and leaves of ＇Changfu 2＇ and its spur sport ＇Longfuduanzhi＇ were used as experimental materials for measuring the content of GA and cloning the genes which involved in the GA synthesis pathway at the four time points days after flowering and researching the relationship between GA and the internode length of shoots at shoot development stage. [ Result] The GA content was significantly different between the spur type apple and non-spur type apple on 80th day after flowering. The GA content was lower in spur type sport compared with in non-spur type apple varieties on 80th day after flowering. The sequences analysis showed that the cDNA sequences of GA2Oox and KO, key genes involved in GA synthesis, were the same between ＇Longfuduanzhi＇ and ＇Changfu 2＇. The mutation, insertion and deletion were not appeared in GA2Oox and KO. The real-time quantitative PCR analysis showed that the relative expression of GA2Oox and KO were significantly different between ＇Longfuduanzhi＇ and ＇Changfu 2＇ on 20th and 80th day after flowering. The relative expression of GA2Oox and KO was lower in spur type apple compared with non-spur type apple on 20th and 80th day after flowering. [ Conclusion ] The research results showed that the difference of GA content and key genes expression of GA synthesis pathway were related to shoot intemode length of spur sport apple. The lower GA content and genes involved in GA synthesis pathway were down-regulated expression which inhibited the normal development of spur sport al：ple shoots. This study has provided basic information for further exploration of the spur type development mechanism.
出处
《中国农业科学》
CAS
CSCD
北大核心
2012年第13期2668-2675,共8页
Scientia Agricultura Sinica
基金
国家自然科学基金项目(31171932)
国家重点基础研究发展计划项目(2011CB100606)
