玫瑰β-l,3-葡聚糖合成酶基因和β-l,3-葡聚糖酶基因克隆与调控授粉亲和性的功能分析

The application of rugosa rose（Rosa rugosa）in the gardens was rare by reason of few variety, short florescence and single color. New varieties of rugosa rose with strong stress resistance and high aesthetic value could be bred by interspecific hybridization with Chinese rose（Rosa chinensis）.But because the mechanism of interspecific hybridization incompatibility between them was unknown, the breeding progress was all through very slow. The application of ornamental fruit rugosas in the gardens was restricted because of their completely self-incompatible, so overcoming their self-incompatibility was of prime importance. But the self-incompatibility mechanism was still unkown..Our studies suggested that the growth phenomena were extremely similar between interspecific pollinated pollen tubes and self-pollinated pollen tubes: The pollen tubes were arrested at the upper one third of the styles and a large amount of callose deposited in the pollen tubes apex and the styles. It maybe was the importance reason of interspecific hybridization incompatibility and self-incompatibility. But the related reports were not yet found..The synthesis and hydrolysis of β-l,3-glucan synthase and β-l,3-glucanase were catalyzed by β-l,3-glucan synthase gene and β-l,3-glucanase gene. So we intended to clone the two genes and discuss their mechanism of regulating pollination compatibility. It could provide theory evidence to overcome interspecific hybridization incompatibility and self-incompatibility, improve breeding and application efficiency of rugosa rose.

玫瑰（Rosa rugosa）因品种少、花期短、花色单调而在园林中应用较少，与月季进行种间杂交可培育出兼具高抗性和高观赏性的新品种。但因一直未搞清二者杂交不亲和机理而导致进展缓慢。观果玫瑰都具完全自交不亲和性，自交授粉不结果，为园林应用造成不便。所以，克服其自交不亲和性具有重要价值，但其自交不亲和机理还是个未知数。.根据我们多年研究发现，玫瑰种间杂交花粉管在花柱里的生长状态与自交花粉管极其相似，都是花粉管在花柱上部1/3处停止生长，且胼胝质在花粉管顶端和花柱内大量沉积。这可能是造成玫瑰种间杂交不亲和与自交不亲和的重要原因。但国内外未见其机理报道。.胼胝质合成与水解分别由β-l,3-葡聚糖合成酶和β-l,3-葡聚糖酶催化完成。所以，本项目拟克隆出这两个基因，并初步探讨其调控授粉亲和性的机理，为克服玫瑰种间杂交不亲和性与自交不亲和性、提高玫瑰育种和应用效率提供理论依据。

玫瑰（Rosa rugosa）种间杂交不亲和性和自交不亲和性严重阻碍了其育种进程和园林应用。根据我们多年研究发现，玫瑰种间杂交不亲和与自交不亲和可能与胼胝质有关。胼胝质合成与水解分别由β-l,3-葡聚糖合成酶和β-l,3-葡聚糖酶催化完成。所以，本项目从玫瑰花柱中克隆出了这两个基因，并初步探讨了其调控授粉亲和性的机理，为克服玫瑰种间杂交不亲和性与自交不亲和性、提高玫瑰育种和应用效率提供了理论依据。主要结论如下：. 1、玫瑰β-l,3-葡聚糖合成酶基因RrCalS（KU221264）全长5742 bp，编码1764个氨基酸，属于葡聚糖合成酶基因超家族；玫瑰β-l,3-葡聚糖酶基因RrGlu（KU144821）全长1380 bp，编码346个氨基酸，属于糖基水解酶基因第17家族。. 2、不同授粉方式均能够显著上调β-l,3-葡聚糖合成酶基因的表达，尤其是不亲和（自交和种间杂交）花柱中的β-l,3-葡聚糖合成酶基因的表达，同时显著抑制β-l,3-葡聚糖酶活性，尤其是不亲和（自交和种间杂交）花柱中的β-l,3-葡聚糖酶活性，使得不亲和（自交和种间杂交）花柱中的胼胝质含量显著大于亲和（品种间杂交）花柱中的胼胝质含量。. 3、胼胝质在花粉管和花柱中的沉积模式分析表明，胼胝质极有可能通过2种方式抑制自交和种间杂交花粉管生长：一是花粉管顶端过量沉积的胼胝质塞影响花粉管自身的极性生长；二是花柱通道细胞及间隙中沉积的胼胝质对花粉管生长产生机械阻碍作用。. 4、玫瑰β-l,3-葡聚糖酶基因在花烟草中的过量表达，降低了花烟草自交、品种间杂交和种间杂交花柱中的胼胝质含量，提高了花烟草自交、品种间杂交和种间杂交的结籽率，影响了花烟草的授粉亲和性。. 综上所述，玫瑰β-l,3-葡聚糖酶基因的确可以通过调控胼胝质的水解参与调控玫瑰授粉亲和性。但玫瑰β-l,3-葡聚糖合成酶基因是否具有授粉亲和性调控功能还需要进一步的转基因验证。