State Key Laboratory of Rice Biology, Institute of Insect Science, Zhejiang University, Hangzhou 310058, China.
Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Neuchâtel 2000, Switzerland.
Int J Mol Sci. 2019 Mar 19;20(6):1369. doi: 10.3390/ijms20061369.
Desaturases are essentially required for unsaturated fatty acid (UFA) biosynthesis. We identified 10 genes encoding putative desaturases in the transcriptome database of the brown planthopper (BPH), . These include eight First Desaturase family genes, one cytochrome b5 fused desaturase gene () and one Sphingolipid Desaturase gene (). Transcript level profiling revealed significant variation in the expression patterns of these genes across tissues and developmental stages, which occur in a gene-specific manner. Interestingly, their expression was also modulated by the insect food source: the mRNA levels of and were down-regulated, but the expression level of and were elevated in the BPH fed on the resistant rice variety Babawee as compared to the non-resistant variety Taichun Native 1 (TN1). Silencing , , or reduced fatty acid composition and abundance in female BPH 1-d-old-adults compared to controls. Whereas, single knockdown of all ten desaturase genes significantly increased mortality of BPH nymphs compared with controls. Of the ten desaturase genes, knockdown of and caused the highest mortality in BPH (91% and 97%, respectively). Our findings offer a base for expression and functional characterization of newly identified desaturase genes in BPH, and may contribute to RNA interference-based pest management strategies.
去饱和酶对于不饱和脂肪酸（UFA）的生物合成是必不可少的。我们在褐飞虱转录组数据库中鉴定了 10 个编码假定去饱和酶的基因。这些基因包括 8 个第一去饱和酶家族基因、1 个细胞色素 b5 融合去饱和酶基因（）和 1 个鞘脂去饱和酶基因（）。转录水平分析显示，这些基因在不同组织和发育阶段的表达模式存在显著差异，且具有基因特异性。有趣的是，它们的表达也受到昆虫食物源的调节：与非抗性品种 Taichun Native 1（TN1）相比，在抗褐飞虱品种 Babawee 上喂食的褐飞虱中，和的 mRNA 水平下调，但和的表达水平上调。与对照相比，沉默、或导致雌褐飞虱 1 日龄成虫的脂肪酸组成和丰度降低。然而，与对照相比，单独敲低这 10 个去饱和酶基因显著增加了褐飞虱若虫的死亡率。在这 10 个去饱和酶基因中，和的敲低导致褐飞虱的死亡率最高（分别为 91%和 97%）。我们的研究结果为褐飞虱新鉴定的去饱和酶基因的表达和功能特征提供了基础，并可能有助于基于 RNA 干扰的害虫管理策略。
