Jinggangmycin increases fecundity of the brown planthopper, Nilaparvata lugens (Stal), via fatty acid synthase gene expression

Authors: LI, LEI - Yangzhou University; JIANG, YIPING - Yangzhou University; LIU, ZONGYU - Yangzhou University; WU, YOU - Yangzhou University; XU, BING - Yangzhou University; WU, JIN-CAI - Yangzhou University; Stanley, David; SONG, QISHENG - University Of Missouri

Submitted to: Journal of Proteomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2015
Publication Date: 1/1/2016
Citation: Li, L., Jiang, Y., Liu, Z., Wu, Y., Xu, B., Wu, J., Stanley, D.W., Song, Q. 2016. Jinggangmycin increases fecundity of the brown planthopper, Nilaparvata lugens (Stal), via fatty acid synthase gene expression. Journal of Proteomics. 130(2016)140-149.

Interpretive Summary: Long-term agricultural sustainability is severely threatened by widespread use of classical insecticides. Threats include increasing resistance to insecticides and sharply decreasing environmental quality. These issues drive research into alternatives to classical insecticides. One potential alternative is based on applying molecular tools to inhibit expression of genes that are crucial to insect pest biology. In this paper, we examined the impact of inhibiting genes responsible for production of fatty acids in a pest insect species. We found that inhibiting fatty acid production by the pest led to retarded development, reduced adult weights and reduced fecundity. These findings demonstrate that fatty acid production may be a novel target for developing insect pest control technologies. This research will influence scientists working to develop novel pest control technologies and, ultimately, will benefit farmers who produce food crops and the people who consume them.

Technical Abstract: The antibiotic jinggangmycin (JGM) is mainly used in controlling the rice sheath blight, Rhizoctonia solani, in China. JGM also enhances reproduction of the brown planthopper (BPH), Nilaparvata lugens (Stål). To date, however, molecular mechanisms of the enhancement are unclear. Our related report documented the influence of foliar JGM sprays on ovarian protein content. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) protocols to analyze ovarian proteins of BPH females following JGM spray (JGM-S) and topical application (JGM-T). We recorded changes in expression of 284 proteins (142 up-regulated and 142 down-regulated) in JGM-S compared to the JGM-S control group (S-control); 267 proteins were differentially expressed (130 up and 137 down) in JGM-T compared to the JGM-T control group (T-control), of which, 22 proteins were up-regulated in both groups. Comparing the JGM-S to the JGM-T group, 114 proteins were differentially expressed (62 up and 52 down). Based on the biological significance of fatty acids, pathway annotation and enrichment analysis, we designed a dsRNA construct to silence a gene encoding fatty acid synthase (FAS). FAS was more highly expressed in JGM-S vs S-control and JGM-S vs JGM-T groups. The dsFAS treatment reduced fecundity by about 46% and reduced ovarian and fat body fatty acid concentrations in JGM-S-treated females relative to controls. We infer FAS provides critically needed fatty acids to support JGM-enhanced fecundity in BPH.