摘要： 为了丰富可利用的植物凝集素基因,获得具有较高抗蚜水平的小麦新种质,采用"Gene Shuffling"策略人工合成中国水仙凝集素基因(sNTL),并转化小麦以分析其抗蚜效果。结果表明:根据小麦遗传密码偏好性人工合成了植物凝集素sNTL基因,并构建了sNTL表达载体;用基因枪转化小麦品种中优9507和丰优6号的幼胚愈伤组织,经PPT筛选和分化后,获得T₀植株,对T₀植株进行PCR筛选而获得阳性植株28株。并经过连续PCR检测,表明sNTL基因已经初步与小麦基因组进行整合并且能够稳定表达。对T₂转基因株系进行室内离体叶片抗虫效果分析,结果表明,转sNTL株系使蚜虫致死率达到53.1%~59.4%,其中转基因株系zy9-4的蚜虫致死率最高,比其对照品种中优9507高24.8%,同时其蚜虫增长率最小为22.1%,比对照品种中优9507低了约49.6%;转基因株系fy4-2使蚜虫致死率比对照(丰优6号)高约14.1%,而其蚜虫增长率比对照降低达到33.4%。对T₃转基因株系田间鉴定结果显示,同对照中优9507相比,zy9-4、zy9-8单分蘖蚜虫发生量分别降低51.4%,45.1%,达到显著或极显著水平;fy4-2、fy4-4与对照丰优6号相比,单分蘖蚜虫发生量降低水平分别为58.7%,76.9%。综合室内与田间抗虫鉴定结果证明,利用人工合成的sNTL基因可以有效地提高小麦的抗蚜性。

关键词: sNTL 基因, 转基因小麦, 小麦蚜虫, 抗虫性

Abstract: Plant lectins have been shown to be toxic to sap-sucking pest such as wheat aphids.In order to obtain the potential lectin gene and aphid-resistant wheat germplasm,a sNTL (synthesized Narcissus tazetta lectin) gene was synthesized using the Gene Shuffling method and the transgenic wheat lines were produced to check the resistance to aphid.In this study,a sNTL gene encoding mannose binding lectins was synthesized according to the codon preferences of wheat genes,and driven by constitutive and phloem-specific rbcs promoter in the constructs.The sNTL gene was transferred into two wheat cultivars (Zhongyou 9507 and Fengyou 6) by particle bombardment transformation.After selected by BASTA and differentiation,twenty-eight T₀ transgenic plants were generated.The integration and transcription of the sNTL gene were confirmed by PCR and RT-PCR analysis respectively.Insect bioassay on detached leaf segments reveal:the aphid mortality of sNTL transgenic wheat lines ranged from 53.1% to 59.4%.The highest aphid mortality was found in sNTL transgenic line zy9-4,and the rate was 24.8% higher than that of the Zhongyou 9507 control,followed by fy4-2 with 14.1% higher aphid mortality and 33.4% lower aphid growth rate than that of the Fengyou 6 control.Insect bioassay in isolated field showed that aphids number per tiller of transgenic lines zy9-4,zy9-8,fy4-2 and fy4-4 were decreased by 51.4%,45.1%,58.7% and 76.9% respectively compared with corresponding control plants.The sNTL transgenic lines were found to be highly resistant to aphids compared to the corresponding control plants.Therefore,sNTL is a strong biotechnological candidate for use in efforts to produce aphid-resistant wheat using genetic modification approachs.

Key words: sNTL gene, Transgenic wheat, Wheat aphid, Insect resistance

中图分类号: 

• Q78

• S435.12