抗南方根结线虫新疆野生樱桃李巨细胞的发育及CCS52B基因的作用  

Development of Giant Cells and Roles of CCS52B Gene Work in Meloidogyne incognita Resistant Prunus sogdiana

作　　者：陈雪峰[1] 肖坤[1] 朱翔[1] 陈伟阳[1] 杨颖[1] 胡建芳[1] 

机构地区：[1]中国农业大学农学与生物技术学院,北京100193

出　　处：《园艺学报》2015年第5期843-852,共10页Acta Horticulturae Sinica

基　　金：国家自然科学基金项目(31471842)

摘　　要：以对南方根结线虫(Meloidogyne incognita)表现感病和抗病的新疆野生樱桃李(Prunus sogdiana Vassilcz.)绿枝扦插苗为材料,观察接种南方根结线虫(Meloidogyne incognita)后在侵染数量、巨细胞发育以及CCS52B基因表达方面的差异。结果显示:在感病植株中南方根结线虫的侵染数量明显高于抗病植株。感病植株接种5 d时已可观察到大量线虫建立了取食位点,到21 d线虫已经成熟、产卵并完成其生活史。而在抗病植株中,接种7 d后仅在少数植株中观察到线虫建立了取食位点,到21 d时观察到大量线虫发育停滞,个别线虫到接种后35 d才发育成雌虫。感病植株的巨细胞面积和细胞核面积明显大于抗病植株。CCS52是一类核内周期激活因子,对于核内复制以及依赖于染色体加倍的细胞膨大至关重要。在樱桃李中,CCS52B基因在感病和抗病植株中都只在巨细胞中表达,并且感病植株中早期表达强于抗病植株,说明在感病植株中线虫容易建立取食位点并完成生活史,是由于CCS52B基因参与了巨细胞形成与发育,其早期的高表达提高了巨细胞中的核内复制,促进了细胞核倍性增加,进而促进巨细胞发育从而有利于线虫发育,导致植株感病。Used the Meloidogyne incognita susceptible and resistant Xinjiang wild cherry plum's greenwood cutting seedlings as the materials,the diversity of nematode infection amount,giant cell's development and CCS52 B expression between susceptible and resistant plants were observed. The results show that the number of M. incognita infected into susceptible plants is significantly higher than resistant ones. In susceptible plants,a large number of nematodes had established feeding sites 5 days after inoculation. After 21 days,these nematodes matured and completed its life cycle. But in resistant plants,only a small number of feeding sites were observed 7 days after inoculation. Twenty-one days after inoculation,most nematodes' development were arrested,few can develop into adults 35 days after inoculation. The area of gaint cell and nuclei surface in susceptible plants are significantly larger than resistant plants'. CCS52 is a family of endocycle activator genes,essential for endore-duplication and ploidy-dependent cell enlargement. CCS52 B is gaint cell-specific expression in Xinjiang wild cherry plum. Besides,its expression in susceptible plants is stronger than in resistant ones,indicating the involvement of CCS52 B in the gaint cell's formation and development. Such involvement benefits nematodes to establish feeding sites and to complete its life cycle much easier in susceptible plants than in resistant ones. Its high expression in susceptible plants enhanced endoreduplication and increased the giant cell nucleus ploidy,both of which contributing to the development of giant cells and therefore leading the plants susceptible.

关 键 词：樱桃李 根结线虫 巨细胞 CCS52B基因 

分 类 号：S662.3[农业科学—果树学]