两型粘虫飞行力分化的线粒体脂肪代谢能力基础及其调控机制

The oriental armyworms, Mythimna separate (Walker), as an important agricultural pest, have the migrant and resident phases. We could inhibit the occurrence, as well as the flight capacity of the migrant phase, to control the diffusion and break-out of this pest. This strategy dependent on the understating of bioenergetics mechanism for divergence of these two phases, which with very few reports. According to our previous comparisons of the mitochondrial morphology and function, as well as the transcription profiles in the flight muscles between two phases, we proved that the mitochondrial fatty acid metabolism, which critical for the bioenergy supply in flight muscle, correlated closely to the divergence of the flight capacity between two phases. For the purpose of discovering the regulation mechanism of the mitochondrial fatty acid metabolism on the alteration of this armyworms’ flight ability, the oxidative phosphorylation function and the critical enzymes of fatty acid metabolism in mitochondria will be compared. Afterward, to find the genes for regulating the alteration of the mitochondrial fatty acid metabolism between two phases, the transcription profiles of different development stages of flight muscle in two phases will be compared. At last, the regulatory functions of the selected critical genes for the mitochondrial fatty acid metabolism will be tested by RNA interference (RNAi) and pharmacological interference experiments. Our study is of great significance in practice and theory, not only supplying the target genes and theory foundation for the new strategy of predicting and controlling the oriental armyworms, which basing on controlling the migrant phase of this pest, but also strengthening our knowledge of the bioenergetics mechanism for insect migration ability.

重大农业害虫粘虫存在迁飞型和居留型两种生态型，可通过抑制迁飞型的发生或其飞行能力控制粘虫的扩散、爆发。这依赖于对两型粘虫飞行力分化过程的能量供应机制的深入了解，但少有报道。根据两型粘虫的线粒体形态和功能、飞行肌转录谱的前期比较，我们发现能量供应的关键部分，即飞行肌线粒体脂肪代谢能力的变化与两型粘虫飞行力的分化密切相关。为了进一步揭示两型粘虫飞行力分化的线粒体脂肪代谢能力基础及其调控机制，本项目拟从线粒体氧化磷酸化过程和脂肪代谢重要酶系活性两个层面阐释粘虫两型在飞行肌线粒体脂肪代谢能力上的差异特征；然后，通过对不同发育时期的粘虫两型飞行肌转录谱的比较，鉴定与线粒体脂肪代谢功能及其调控相关的基因，最后筛选关键调控基因，并通过RNAi和药物干扰方法验证其对粘虫飞行能力的调控功能。本研究可为基于迁飞型粘虫控制的预测预警和防控新思路提供靶标基因和理论依据，也将促进对迁飞昆虫飞行能量供应机制的深入了解

重大农业害虫粘虫存在迁飞型和居留型两种生态型，可通过抑制迁飞型的发生或其飞行能力控制粘虫的扩散、爆发。这依赖于对两型粘虫飞行力分化过程的能量供应机制的深入了解，但少有报道。本项目在建立典型而稳定的迁飞型和居留型粘虫品系基础上，明确其生理和飞行能力方面的分化特征，并进一步比较分析了两型粘虫在飞行肌的超微结构、线粒体形态、脂肪代谢功能、关键酶活等特征，结果表明皆无显著差异，说明线粒体的脂肪代谢功能未参与调控两型粘虫飞行能力的分化。另一方面，通过脂肪含量的比较，发现在粘虫发育过程中，迁飞型粘虫脂肪含量显著高于居留型。进一步比较了粘虫不同幼虫龄期的肠道微生物种群结构特征，结果表明3,4龄幼虫期在多样性、种群结构、主要组成菌群上具有显著的差异，表明3,4龄幼虫期可能是两型粘虫分化的关键时期；而功能预测分析也证明两型粘虫幼虫期肠道微生物的脂肪代谢功能相关菌群百分占比具有明显差异，预示着肠道微生物群落的差异可能参与了两型粘虫脂肪积累能力分化的调控。最后，在粘虫肠道微生物中分离得到一株木质纤维素分解菌，具有极高的木聚糖分解和中等的纤维素分解活性，鉴定命名为Bacillus velezensis ZY-1-1，并进一步获得完整基因组序列，预测了木质纤维素分解关键酶活基因。以上结果明确了飞行肌能量供应特征未参与调控迁飞型和居留型粘虫飞行能力的分化，同时预示肠道微生物参与了两型粘虫脂肪积累能力的分化，并获得一株优良的木质纤维素分解菌。这些发现不仅有利于深入了解迁飞昆虫飞行能量供应机制，也从肠道微生物角度为迁飞型粘虫的预防提供了新思路。