牡丹SKP1基因功能研究

Recently, great progress has been made on molecular genetics of flower development, which laid theoretical base on the molecular breeding for ornamental plants. However, research innovation is limited to the modal plant, it is necessary to explore molecular mechanism on flower development and genetics for non-modal plant especially for flower plants including tree peony due to its industrialization. Tree peony (Paeonia suffruticosa) is an important resources plant with great values on the history, culture, ornament and medicine. Based on the former study and progress on molecular mechanism of tree peony flower shapes, in order to explore the stamen/carpel petaloid and solve the problem on the short flowering period of single flower, in this project, we attempt to screen the cDNA library of flower bud from tree peony to obtain the SKP1 homologus gene, then transfer it to the Arabidopsis plant through overexpression, by analysis on the phenotypes of flower development to characterize its function, and deduced its function on the flower development of tree peony. We will study the way for SKP1 performing its function by yeast two-hybrid analysis on the interaction between SKP1 and F-box proteins. This study will help to explain its funtion in flower development and other developmental process in tree penoy.It will provide theoretical base and functional gene for flower development regulation and molecular breeding of tree peony.

近年来，模式植物花器官进化发育遗传学领域取得了许多重要的研究进展，为花卉分子育种奠定了理论基础，花卉产业的快速发展迫切需要在牡丹等非模式植物的传统名花中探讨其花发育分子机制。牡丹集历史、文化、观赏和药用价值于一身，其花发育过程中存在雄蕊/心皮瓣化现象和单花花期短等问题，本研究拟通过筛选牡丹花芽cDNA文库，获得SKP1基因，并将其转入拟南芥，验证SKP1在花发育等过程中的功能；通过酵母双杂交研究牡丹SKP1与F-BOX蛋白的互作能力，以期揭示SKP1在牡丹花发育过程中的重要调控机制，为牡丹分子育种等提供功能基因和科学依据。

从牡丹中克隆得到了S期激酶关联蛋白1 ( SKP1) 同源基因将其命名为PSK1(Paeonia sufruticosa SKP1-like1)，其开放阅读框（ORF）长462bp，推测编码153个氨基酸，分子量17 kDa。其全长基因1634bp， 含有一个大的内含子长度为904bp。荧光定量分析结果表明，PSK1在所有检测组织中均表达，并且在萼片中表达量较高，其次是叶片中，在花发育的S3期表达量最高。亚细胞定位结果表明，其定位在细胞质尤其是内质网中。将PSK1过量表达在拟南芥中，盐胁迫下，转基因拟南芥株系表现出萌发率、绿色子叶数、鲜重均高于野生型对照植株。另外，转基因株系中的ASK1、 LEAFY、FT、 CO的表达量均显著高于野生型对照，这些基因表达对其生长和开花具有重要意义，并使得转基因株系提早开花1周左右；盐胁迫相关的基因包括P5CS，RAB18，DREB，SOD1-3等在转基因株系中的表达量较高，对增加其盐胁迫的耐受能力有重要意义。我们对牡丹中SKP1同源基因（PSK1）的研究对于丰富这一家族基因功能具有重要意义，并揭示了其在盐胁迫中发挥功能的可能机制，并为研究其在牡丹花发育中作用的分子机制提供了重要信息，为牡丹花期调控和盐胁迫耐受的机制研究奠定了基础。