The Molecular Mechanisms Of Jinggangmycin Stimulated The Reproduction Of Nilaparvata Lugens(St(?)l) But Suppressed The Reproduction Of Sogatella Furcifera (Horváth)

Guild is a hot topic in modern ecology study. Planthopper guild in rice field, including the brown planthopper (BPH), the white-backed planthopper (WBPH) and the small brown planthopper (SBPH), is major devastating pests, and also is tipical resurgent pests, their resurgence mechanisms are worthy to be further studied. Many researchers only study one species of planthoppers, their guild is few studied. Our lab studied effect of pesticides on planthopper guild, and found a phenomenon:jinggangmycin (JGM) stimulated the reproduction of BPH but suppressed the reproduction of WBPH. To explain the phenomenon, we will select one key gene associated with reproduction and metabolism and study the gene function by RNAi based on the analysis of gene expression profiles of pesticide-treated BPH and transcriptome of treated WBPH. The objective is to understand the molecular mechanisms of the inverse effect of pesticide-induced of reproduction of palnthopper guild. 1 Analysis of JGM-treated BPH’s gene expression profiles and JGM-treated WBPHs transcriptome and the influence of ATGL on BPH reproductive.Brown planthopper have a high reproductive capacity. They are also typical resurgent pests induced by pesticide. Most studies show that planthopper outbreak is associated with the use of pesticides. The antibiotic jinggangmycin (JGM) is an agrochemical product widely used in China for controlling rice sheath blight, Rhizoctonia solani. Unexpectedly, our recent study found an important and interesting phenomenon:JGM stimulated the reproduction of BPH but suppressed the reproduction of WBPH. However, the underlying molecular mechanisms of the stimulation or suppression are unclear. We have select one key genes associated with lipolysis from analysis of pathway of gene expression profiles of pesticide-treated BPH and transcriptome of treated WBPH. We finally selected adipose triglyceride lipase (ATGL) gene in BPH, carboxylesterase precursor (CES) gene in WBPH for RNAi test, which the two genes are in the same position of pathway. Silence of ATGL in JGM-treated (JGM+dsATGL) females eliminated JGM-stimulated increase in fecundity of BPH females. In addition, the protein contents by JGM+dsATGL females was significantly lower than those of JGM-treated (without ATGL silencing), with the protein contents decreasing by 40.10% and 33.80%, respectively. The glycerin contents and the number of eggs laid per female by JGM+dsATGL females were significantly lower than those of JGM-treated (without ATGL silencing), which decreasing by 35.0% and 30.61%, respectively. We conclude that ATGL is one of the key enzymes responsible for JGM-stimulated reproduction of BPH.2 Carboxylesterase precursor (CES) gene cloning and its influence on WBPH reproductiveWBPH is one of the major pests on rice. Previous studies have found JGM suppressed the reproduction of WBPH, and we select CES gene based on the analysis of the transcriptome of pesticide-treated WBPH for RNAi test. Because of lacking of CES gene sequence, firstly, we cloned CES gene to get the complete sequence, then based on BlastP of the NCBI website, we find CES gene of WBPH is highly homologous with BPH, and confirmed that the gene is a gene that we need. Then we verified its function by RNAi. The results show that CES knockdown significantly reduced the protein and soluble sugar content required for reproduction in the ovaries of Control+dsCES females, The number of eggs laid per female by control+dsCES WBPH females was significantly lower than those of control-treated (without CES silencing) or control+dsGFP females (negative control), decreasing by 58.23%(from 233.78 to 93.67) and 58.09%(from 233.06 to 97.67), respectively. The oviposition period and the adult female longevity by control+dsCES females were significantly shorter than those of control-treated, decreasing by 37.61% and 37.83%, respectively. The protein and the soluble sugar contents in the ovaries by control+dsCES WBPH females were significantly lower than those of control-treated, decreasing by 43.86% and 20.41%, respectively. Thus, we considered that CES is one of the key enzymes responsible for JGM-suppressed reproduction of WBPH.