柿性器官败育及相关基因的表达

Expression analysis for abortion of sex organs and related-genes in persimmon(Diospyros kaki)

为描述柿Diospyros kaki性器官败育现象,以中国林业科学研究院经济林研究开发中心原阳试验基地10年生的雌雄同株柿品种‘禅寺丸’‘Zenjimaru’为研究对象,通过制作石蜡切片结合外部形态变化,同时利用实时定量聚合酶链式反应(qRT-PCR)技术对6个性别分化相关基因进行表达模式分析,对柿花芽分化过程中的性器官败育的关键时期及分子调控机制进行了研究。结果表明:柿雌花中的雄蕊原基和雄花中的雌蕊原基均在4月中旬发生败育。此时,顶端着生雌花的枝条长为5.0～6.0 cm,着生雄花的枝条长为6.0～8.0 cm,雌花芽长约1.0 cm,雄花芽长为1.0～2.0 cm。除了4月5日和4月8日外, ANT和LYK3基因在其他发育阶段均差异显著(P<0.05)且在雌花芽中的表达量明显高于雄花芽,而AP2和ABCC10基因则是在雄花芽中的表达水平显著高于雌花芽(P<0.05)。在4月5日和4月14日(性器官败育关键时期),基因BI-1在雌花芽中的表达量分别是雄花芽的1.5倍和2.0倍,而在其余阶段,其表达量分别是雄花芽的97.5%, 89.2%和83.9%,推测BI-1作为一种雄性器官细胞凋亡抑制基因,间接促进柿雄花芽的发育。建议对树体进行正常的修剪、施肥等常规处理的同时,在4月中旬花器官原基败育之前对树体进行相应激素的喷施,以调控柿花性别,培育雄性种质。

The abortion of sex organs in Diospyros kaki(persimmon)has not yet been clearly elucidated.To investigate the key period for expression patterns dealing with abortion of sex organs and related-genes in persimmon,paraffin section method and morphology changes,as well as a qRT-PCR analysis of six floral sex differentiation-related genes,were conducted with a 10-year-old monoecious persimmon cultivar‘Zenjimaru’in the Yuanyang Practice Base belonging to the Non-timber Forestry Research&Development Center,Chinese Academy of Forestry.Results showed that stamen primordium in female flowers and pistil primordium in male flowers both aborted in mid-April with the female branch 5.0-6.0 cm in length,the male branch 6.0-8.0 cm in length,the female floral bud 1.0 cm in length,and the male floral bud 1.0-2.0 cm in length.In addition,during differentiation,excluding the April 5th and April 8th stages,ANT and LYK3 genes were significantly higher(P<0.05)in female floral buds than male;whereas,AP2 and ABCC10 genes in male floral buds were significantly higher than female(P<0.05).The BI-1 level in female floral buds was 1.5 to 2.0 times greater than those in male buds in April 5th and April 14th(the key period for abortion of sex organs),respectively,but it was 97.5%,89.2%,and 83.9%in the other stages.Thus,the BI-1 gene may act as an apoptosis-inhibiter and may be indirectly related to development of stamen primordia.Exogenous phytohormones,that regulate the sex of flower buds and cultivate male persimmon germplasm resources,should be considered along with conventional management before abortion of corresponding sexual organs in mid-April.[Ch,3 fig.1 tab.39 ref.]