Sun Qin-Zhe, Li Xiao-Lin, Shi Yu-Fei, Zhang Yan-Chun, Chai Wen-Jie, Chen Ruo-Yu, Niu Jinzhi, Wang Jin-Jun
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Academy of Agricultural Sciences, Southwest University, Chongqing, China.
Insect Sci. 2023 Oct;30(5):1337-1351. doi: 10.1111/1744-7917.13159. Epub 2023 Jan 6.
Spider mites (Tetranychidae) are destructive agricultural pests which have evolved strategies to overcome plant defenses, such as the ability to puncture the leaves of their hosts to feed. The expression of many genes with unknown functions is altered during feeding, but little is known about the role of these genes in plant-mite interactions. Here, we identified 3 novel gene families through analysis of genomic and transcriptomic data from 3 spider mite species. These GARP family genes encode glycine and alanine-rich proteins; they are present in mites (Acariformes) but absent in ticks (Parasitiformes) in the subclass Acari, indicating that these genes have undergone a significant expansion in spider mites and thus play important adaptive roles. Transcriptomic analysis revealed that the expression of GARP genes is strongly correlated with feeding and the transfer to new hosts. We used RNA interference to silence GARP1d in the two-spotted spider mite Tetranychus urticae, which inhibited feeding and egg laying and significantly increased mortality when the mites were transferred to soybean shoots; a similar effect was observed after TuVATPase was silenced. However, no changes in mite mortality were observed after TuGARP1d-silenced mites were placed on an artificial diet, which was different from the effect of TuVATPase silencing. Our results indicate that GARP family members play important roles in mite-plant interactions. Additional studies are needed to clarify the mechanisms underlying these interactions.
叶螨（叶螨科）是具有破坏性的农业害虫，它们已经进化出克服植物防御的策略，比如能够刺穿宿主叶片以取食。许多功能未知的基因在取食过程中表达会发生改变，但对于这些基因在植物 - 叶螨相互作用中的作用却知之甚少。在这里，我们通过分析三种叶螨物种的基因组和转录组数据，鉴定出了3个新的基因家族。这些GARP家族基因编码富含甘氨酸和丙氨酸的蛋白质；它们存在于螨类（真螨目）中，但在蜱螨亚纲的蜱类（寄螨目）中不存在，这表明这些基因在叶螨中经历了显著的扩增，因此发挥着重要的适应性作用。转录组分析表明，GARP基因的表达与取食以及转移到新宿主密切相关。我们利用RNA干扰技术使二斑叶螨Tetranychus urticae中的GARP1d基因沉默，这抑制了取食和产卵，并且当叶螨转移到大豆嫩枝上时显著增加了死亡率；在沉默TuVATPase后也观察到了类似的效果。然而，将沉默TuGARP1d的叶螨置于人工饲料上后，未观察到叶螨死亡率的变化，这与沉默TuVATPase的效果不同。我们的结果表明，GARP家族成员在叶螨 - 植物相互作用中发挥着重要作用。需要进一步的研究来阐明这些相互作用背后的机制。
