Henosepilachna vigintioctopunctata is a major pest of solanaceous crops. Matrix metalloproteinase 2 (MMP2) is a zinc ion-dependent endopeptidase that plays a crucial role in the remodeling process of the extracellular matrix (ECM) within cells. However, the function of HvMMP2 in H. vigintioctopunctata remains unknown. In this study, we cloned and characterized the HvMMP2 gene in H. vigintioctopunctata and investigated its function using RNA interference (RNAi). HvMMP2 exists as two transcript variants that differ at the 5′ end. HvMMP2 is highly expressed in the prepupal stage, the pupal stage and the intestine. Silencing HvMMP2 expression in fourth-instar larvae led to approximately 54% mortality at the prepupal stage, with the remaining larvae dying after pupation. RNAi with HvMMP2 in third-instar larvae did not affect their development to the fourth instar, but caused mortality in the majority of larvae during the prepupal and pupal stages, and most of these pupae exhibited wing deformities. Examination of these stunted larvae by dissection showed that their fat bodies were abnormally shaped and that yellow uric acid crystals had accumulated in the Malpighian tubules. Collectively, our findings indicate that HvMMP2 plays a critical role in pupation and eclosion in H. vigintioctopunctata and support HvMMP2 as a potential molecular target for further RNAi-based control studies.
Wu et al. (Wed,) studied this question.