Xia Wen-Kai, Shen Xiao-Min, Ding Tian-Bo, Niu Jin-Zhi, Zhong Rui, Liao Chong-Yu, Feng Ying-Cai, Dou Wei, Wang Jin-Jun
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400716, China.
Exp Appl Acarol. 2016 Sep;70(1):1-15. doi: 10.1007/s10493-016-0063-0. Epub 2016 Jul 7.
Chitinases are hydrolytic enzymes that are required for chitin degradation and reconstruction in arthropods. In this study, we report a cDNA sequence encoding a putative chitinase (PcCht1) from the citrus red mite, Panonychus citri. The PcCht1 (564 aa) possessed a signal peptide, a conserver domain, and a chitin-binding domain. Structural and phylogenetic analyses found that PcCht1 had high sequence similarity to chitinases in Tetranychus urticae. Real-time quantitative PCR analyses showed that the transcript levels of PcCht1 peaked periodically in larval and nymph stages. Moreover, significant increase of PcCht1 transcript level in the larvae was observed upon the exposure of diflubenzuron. In contrast, exposures of the larvae to diflubenzuron resulted in the decreased chitin content. Furthermore, through a feeding-based RNA interference approach, we were able to reduce the PcCht1 transcript level by 59.7 % in the larvae, and consequently the treated larvae showed a very low molting rate compared with the control. Our results expanded the understanding of the important role of PcCht1 in the growth and development of P. citri.
几丁质酶是节肢动物中几丁质降解和重建所必需的水解酶。在本研究中，我们报道了一条来自柑橘全爪螨的编码假定几丁质酶（PcCht1）的cDNA序列。PcCht1（564个氨基酸）具有一个信号肽、一个保守结构域和一个几丁质结合结构域。结构和系统发育分析发现，PcCht1与二斑叶螨中的几丁质酶具有高度的序列相似性。实时定量PCR分析表明，PcCht1的转录水平在幼虫和若虫阶段呈周期性峰值。此外，在接触除虫脲后，观察到幼虫中PcCht1转录水平显著增加。相反，幼虫接触除虫脲导致几丁质含量降低。此外，通过基于喂食的RNA干扰方法，我们能够将幼虫中PcCht1的转录水平降低59.7%，因此与对照相比，处理后的幼虫蜕皮率非常低。我们的结果扩展了对PcCht1在柑橘全爪螨生长发育中重要作用的理解。
