Neuropeptides are endogenous active substances that widely exist in multicellular biological nerve tissue and participate in the function of the nervous system, and most of them act on neuropeptide receptors. In insects, neuropeptides and their receptors play important roles in controlling a multitude of physiological processes. In this project, we sequenced the transcriptome from twelve tissues of the Asian citrus psyllid, Diaphorina citri Kuwayama. A total of 40 candidate neuropeptide genes and 42 neuropeptide receptor genes were identified. Among the neuropeptide receptor genes, 35 of them belong to the A-family (or rhodopsin-like), four of them belong to the B-family (or secretin-like), and three of them are leucine-rich repeat-containing G-protein-coupled receptors. The expression profile of the 82 genes across developmental stages was determined by qRT-PCR. Our study provides the first investigation on the genes of neuropeptides and their receptors in D. citri, which may play key roles in regulating the physiology and behaviors of D. citri.
Argonaute (Ago) protein family plays a key role in the RNA interference (RNAi) process in different insects including Lepidopteran. However, the role of Ago proteins in the RNAi pathway of Plutella xylostella is still unknown. We cloned an Argonaute3 gene in P. xylostella (PxAgo3) with the complete coding sequence of 2832 bp. The encoded protein had 935 amino acids with an expected molecular weight of 108.9 kDa and an isoelectric point of 9.29. It contained a PAZ (PIWI/Argonaute/Zwile) domain and PIWI (P-element-induced whimpy testes) domain. PxAgo3 was classified into the Piwi subfamily of Ago proteins with a high similarity of 93.0% with Bombyx mori Ago3 (BmAgo3). The suppression of PxAgo3 by dsPxAgo3 was observed 3 h after treatment and was maintained until 24 h. Knockdown of PxAgo3 decreased the suppression level of PxActin by dsPxActin in P. xylostella cells, while overexpression of PxAgo3 increased the RNAi efficiency. Our results suggest that PxAgo3 play a key role in the double stranded RNA (dsRNA)-regulated RNAi pathway in P. xylostella.
| Pumpkin ( Cucurbita pepo : Cucurbitaceae ) is a heat-labile plant, having nutritional value containing large number of active compounds like carotenoids, alkaloids and flavonoids and necessary for food security against disease causing agents like bacteria, fungi etc. Black rot is a serious disease in pumpkin caused by fungus ( Didymella bryoniae ) and damaged fruit with the symptoms of dark brown lesions but causal organism identification through DNA is still unknown. We collected infected leaf from C. pepp from the vicinity of The University of Agriculture, Faisalabad and isolated D. bryoniae on the respective media. Then morphologically identification was observed through fungal growth pattern, growth color, spores shape, spores color, hyphal septation. For the confirmation of Koch’s postulates, the pathogenicity test was performed. CTAB method and Internal Transcribed Spacer region were applied to isolate and amplify the fungal genomic DNA respectively, by using universal primers ITS1/ITS4. The analysis of polygenetic of an amplified product revealed that black rot caused by D. bryoniae in pumpkin .