Host-mediated attenuation of gut sucrase in mustard aphid Lipaphis erysimi impaired its parthenogenetic reproduction on Indian mustard Brassica juncea
Host-mediated attenuation of gut sucrase in mustard aphid Lipaphis erysimi impaired its parthenogenetic reproduction on Indian mustard Brassica juncea
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DOI：
10.1002/ps.6694
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发表时间：
2021-11-12
影响因子：
4.1
通讯作者：
Bhattacharya, Ramcharan
中科院分区：
文献类型：
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作者：
Dhatwalia, Deepa;Aminedi, Raghavendra;Bhattacharya, Ramcharan
有害的半翅目芥菜蚜虫（Lipaphis erysimi）对包括印度芥菜（Brassica juncea）在内的芸苔属作物造成巨大的产量损失。缺乏可获得的抗性来源一直是培育抗蚜虫品种的主要障碍。近年来，rnai介导的植物抗性已在模式植物中被证明是一种潜在的保护害虫的工具。然而，在作物品种上的转化应用是至关重要的，以便对该技术在育种有效抗性方面进行关键评估。结果蔗糖酶1 （su1）在L. erysimi中的表达模式证实了其在减轻昆虫肠道内富含蔗糖的韧皮部汁液施加的渗透压中的重要作用。建立了表达su1发夹RNA的印度芥菜转基因株系，使其能够通过寄主介导传递到侵染蚜虫体内。通过定量反转录(RT)-PCR、茎环RT-PCR和Northern杂交验证转基因芥菜系中dsRNA编码盒的表达和siRNA分子的产生。在转基因品系上饲养，蚜虫的繁殖力降低22 ~ 40%。蚜虫繁殖迟缓的观察结果与供食转基因系的L. erysimi中su1特异性siRNA分子的检测和su1转录物水平的降低是一致的。结论增强品种抗性可显著减少有毒农药在作物保护中的使用。这一尝试是第一次在任何芸苔作物中成功展示宿主介导的蚜虫基因RNAi。这为在芸苔属作物中更严格地进行基于rnai的抗蚜工程研究铺平了道路。
BACKGROUND The nefarious hemipteran mustard aphid (Lipaphis erysimi) inflicts colossal yield losses in Brassica crops including Indian mustard (Brassica juncea). Lack of an accessible resistance source has been the primary impediment in breeding varietal resistance against aphids. In recent years, in planta RNAi-mediated resistance has been demonstrated in model plants as a potential tool for protection against insect pests. However, translational application in crop species is imperative for critical assessment of this technology in breeding effective resistance. RESULTS The essential role of sucrase 1 (SUC1) in mitigating osmotic pressure imposed by sucrose-rich phloem sap inside the insect gut is corroborated by its expression pattern in L. erysimi. Transgenic lines of Indian mustard were developed expressing SUC1 hairpin RNA for its host-mediated delivery into the infesting aphids. The expression of the dsRNA encoding cassette, and generation of siRNA molecules in transgenic B. juncea lines were verified by quantitative reverse transcription (RT)-PCR, stem-loop RT-PCR and Northern hybridization. Rearing of L. erysimi on the transgenic lines resulted in 22-40% reduction in aphid fecundity. The observed retardation in aphid reproduction was coherent with the detection of SUC1-specific siRNA molecules and attenuation of the SUC1 transcript level in L. erysimi fed on the transgenic lines. CONCLUSION Augmenting varietal resistance can substantially reduce usage of toxic agrochemicals in crop protection. This attempt was the first successful demonstration of host-mediated RNAi of an aphid gene in any Brassica crop. It paves the way for more rigorous attempt of engineering RNAi-based resistance against aphids in Brassica crops.