The results showed that NlugOBP11 was expressed in all stages, and more highly expressed in salivary glands than in other tissues ( Figure 1b,c). To explore the functions of NlugOBP11, mRNA levels were analyzed in different tissues of BPH at different developmental stages by qPCR. Amino acid sequence alignment followed by phylogenetic tree analysis revealed that NlugOBP11 is homologous to other insect OBPs ( Supplementary Figures S1 and S2) NlugOBP11 shared the highest homology (100%) with OBP from delphacidae (Laodelphax striatellus, AGZ04923 Sogatella furcifera, AHB59655) followed by that from Aphididae ( Myzus persicae ACI30682 (66%)) and Acrididae ( Locusta migratoria ACI30696 (58%)). The protein possessed a secretory signal peptide (first 20 amino acids) and has no transmembrane domains, indicating potential secretion. The cDNA contained an ORF of 540 bp encoding a polypeptide of 179 amino acid residues ( Figure 1a). We obtained a full-length cDNA of the NlugOBP11 gene by PCR based on the BPH salivary gland transcriptome. There are numerous proteins in insect saliva, but their functions remain poorly understood. found that Endo-b-1,4-glucanase (an endoglucanase present in BPH watery saliva that is secreted into host plants during feeding) is an effector that helps BPH to circumvent plant defenses. lugens-secreted mucin-like protein (NLMLP) is required for BPH feeding and can induce plant cell death and transcription of pathogen-responsive genes. In recent years, several saliva proteins have been studied in brown planthopper (BPH, Nilaparvata lugens), a devastating rice pest that causes serious economic losses throughout Asia. Similarly, MpMIF (a migration inhibitory factor (MIF) in Myzus percicae) in aphid watery saliva is secreted into plants, where it can affect JA and SA signaling pathways. In Myzus persicae, the MP10 protein suppresses oxidative bursts. In vetch aphid ( Megoura viciae), the saliva contains calcium-binding proteins that induce dispersed forisomes to revert back to the nonplugging contracted state and promote aphid feeding. Numerous effectors have been identified in saliva. For example, the C002 protein (expressed in saliva, and secreted into host plants during feeding) is indispensable for feeding by the pea aphid ( Acyrthosiphon pisum), and overexpression of C002 in Nicotiana benthamiana increases the fecundity of green peach aphid ( Myzus persicae). Insect saliva contains elicitors that induce plant resistance and effectors that inhibit plant defenses. The results demonstrate that NlugOBP11 is not only essential for BPH feeding, but also acts as an effector that inhibits plant defense. Moreover, overexpression of NlugOBP11 in rice protoplasts or Nicotiana benthamiana leaves inhibited the production of defense-related signaling molecule salicylic acid in rice plant. lugens saliva revealed that silencing this gene by RNA interference decreased the BPH stylet performance in the phloem of rice plants, reduced sap sucking, and ultimately led to insect death.

Real-time quantitative PCR and Western blotting analysis results showed that NlugOBP11 was highly expressed in salivary glands and secreted into rice plant during feeding, suggesting that it assists in BPH feeding on rice. Here, we identified an OBP in brown planthopper (BPH) Nilaparvata lugens salivary glands via transcriptome sequencing. Odorant-binding proteins (OBPs) typically act as transporters of odor molecules and play an important role in insect host location.

Plant protoplast transfection midikit