In agricultural systems, crops equipped with host-plant resistance (HPR) have enhanced protection against pests, and are used as a safe and sustainable tool in pest management. In soybean, HPR can control the soybean aphid (Aphis glycines), but certain aphid populations have overcome this resistance (i.e., virulence). The molecular mechanisms underlying aphid virulence to HPR are unknown, but likely involve effector proteins that are secreted by aphids to modulate plant defenses. Another mechanism to facilitate adaptation is through the activity of transposable elements, which can become activated by stress. In this study, we performed RNA sequencing of virulent and avirulent soybean aphids fed susceptible or resistant (Rag1 + Rag2) soybean. Our goal was to better understand the molecular mechanisms underlying soybean aphid virulence. Our data showed that virulent aphids mostly down regulate putative effector genes relative to avirulent aphids, especially when aphids were fed susceptible soybean. Decreased expression of effectors may help evade HPR plant defenses. Virulent aphids also transcriptionally up regulate a diverse set of transposable elements and nearby genes, which is consistent with stress adaptation. Our work demonstrates two mechanisms of pest adaptation to resistance, and identifies effector gene targets for future functional testing.

中文翻译：

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大豆蚜虫通过下调假定效应子和上调转座因子而适应宿主植物的抗性。

在农业系统中，具有寄主植物抗性（HPR）的农作物增强了对害虫的保护，并被用作害虫管理中的安全且可持续的工具。在大豆中，HPR可以控制大豆蚜虫（Aphis甘氨酸），但是某些蚜虫种群已经克服了这种抗性（即毒力）。蚜虫致HPR毒力的分子机制尚不清楚，但可能涉及由蚜虫分泌的效应蛋白来调节植物防御能力。促进适应的另一种机制是通过转座因子的活动，该活动可因压力而激活。在这项研究中，我们对饲喂敏感或抗性（Rag1 + Rag2）大豆的有毒和无毒大豆蚜虫进行了RNA测序。我们的目标是更好地了解大豆蚜虫毒力的分子机制。我们的数据显示，与无毒蚜虫相比，有毒蚜虫大多下调假定的效应基因，尤其是当蚜虫饲喂易感大豆时。效应子表达的减少可能有助于逃避HPR植物防御。毒性蚜虫还通过转录上调多种转座因子和附近基因，这与胁迫适应性一致。我们的工作证明了有害生物适应抗性的两种机制，并确定了效应基因的目标，以进行未来的功能测试。这与压力适应一致。我们的工作证明了有害生物适应抗性的两种机制，并确定了效应基因的目标，以进行未来的功能测试。这与压力适应一致。我们的工作证明了有害生物适应抗性的两种机制，并确定了效应基因的目标，以进行未来的功能测试。