Guangdong Provincial Key Laboratory of New High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
Insect Sci. 2021 Aug;28(4):1061-1075. doi: 10.1111/1744-7917.12848. Epub 2020 Aug 17.
Conopomorpha sinensis is the dominant borer pest of Litchi chinensis (litchi) and Euphoria longan (longan) in China. Control of C. sinensis is difficult because of its cryptic life habit; thus, an effective ovicide could be beneficial. The larvicidal effects of diflubenzuron (DFB) have been documented in many insect pest species. Therefore, DFB might be a useful ovicide to control C. sinensis. However, the detailed mode of action of DFB interference with insect molting and egg hatching is unclear. Thus, we studied alterations in expression of all genes potentially affected by DFB treatment using a transcriptome approach in 2-d-old C. sinensis eggs. Clean reads were assembled to generate 203 455 unigenes and 440 558 transcripts. A total of 4625 differently expressed genes, which included 2670 up-regulated and 1955 down-regulated unigenes, were identified. Chitin binding and chitin metabolic processes were among the most significant enriched pathways according to Gene Ontology analyses. Most of the genes that encode enzymes involved in the chitin biosynthesis pathway were unaffected, whereas genes that presumably encode cuticle proteins were up-regulated. Furthermore, altered expression patterns of 10 genes involved in the chitin biosynthesis pathway of C. sinensis embryos were observed in response to DFB treatment at different time points by quantitative reverse transcription polymerase chain reaction. We also observed abnormal development; there was reduced chitin content and modulated chitin distribution of newly hatched larvae, and altered egg hatching. Our findings illustrate an ovicidal effect of DFB on C. sinensis, and reveal more molecular consequences of DFB treatment on insects.
荔枝蝽和龙眼鸡在中国是荔枝和龙眼的主要蛀干害虫。由于其隐密的生活习性，防治荔枝蝽较为困难；因此，有效的杀卵剂可能会有所帮助。在许多昆虫害虫物种中都有记录到除虫脲（DFB）的杀虫效果。因此，DFB 可能是防治荔枝蝽的一种有用的杀卵剂。然而，DFB 干扰昆虫蜕皮和卵孵化的详细作用模式尚不清楚。因此，我们使用转录组学方法研究了 DFB 处理对 2 日龄荔枝蝽卵中所有可能受其影响的基因表达的改变。将清洁的读数组装起来，生成了 203455 个 unigenes 和 440558 个转录本。总共鉴定出 4625 个差异表达基因，其中包括 2670 个上调和 1955 个下调的 unigenes。根据基因本体分析，几丁质结合和几丁质代谢过程是最显著的富集途径之一。大多数编码参与几丁质生物合成途径的酶的基因没有受到影响，而推测编码表皮蛋白的基因则被上调。此外，通过定量逆转录聚合酶链反应观察到 DFB 处理在不同时间点对荔枝蝽胚胎几丁质生物合成途径的 10 个基因的表达模式发生了改变。我们还观察到异常发育；新孵化幼虫的几丁质含量降低，几丁质分布发生改变，卵孵化也受到影响。我们的研究结果表明 DFB 对荔枝蝽具有杀卵作用，并揭示了 DFB 处理对昆虫的更多分子后果。
