|ZHANG, YI-XIN - Yangzhou University|
|JIANG, YI-PING - Yangzhou University|
|LU, XIU-LI - Yangzhou University|
|LI, XIN - Yangzhou University|
|GE, LIN-QUAN - Yangzhou University|
|SONG, QI-SHENG - University Of Missouri|
|WU, JIN-CAI - Yangzhou University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2015
Publication Date: 10/20/2015
Citation: Zhang, Y., Jiang, Y., Lu, X., Li, X., Ge, L., Stanley, D.W., Song, Q., Wu, J. 2015. RNAi knockdown of acetyl-CoA gene eliminates jinggangmycin-enhanced reproduction and population growth in the brown planthopper, Nilaparfata lugens. Scientific Reports. 5:15360.
Interpretive Summary: Some crops are regularly attacked by fungal plant pathogens. Rice blight is a fungal disease that is controlled by applying a fungicide. Here we investigated the influence of a fungicide on insect pests of rice, the brown planthopper and the white-backed planthopper, both serious rice pests. The fungicide stimulated reproduction of the brown planthopper and suppressed it in the white-backed planthopper. We found that silencing expression of an enzyme that acts in fat biosynthesis eliminated the fungicide-induced increases in reproduction in the brown planthopper but not the white-backed planthopper. This explains how two very similar species can co-exist, that is, they have evolved different reactions to an agricultural chemical. The significance of this finding is that it provides important information on the timing of fungicide applications. In rice, a global crop, the recommendation would be to apply the fungicide early in the growing season, when the white-backed planthopper, but not the brown planthopper is present. This work will be of use to agricultural advisors, to growers and to consumers.
Technical Abstract: A major challenge in ecology lies in understanding the coexistence of intraguild species, well documented at the organismal level, but not at the molecular level. This study focused on the effects of the antibiotic, jinggangmycin (JGM), a fungicide widely used in Asian rice agroecosystems, on reproduction within the planthopper guild, including the brown planthopper (BPH) Nilaparvata lugens, the white-backed planthopper (WBPH) Sogatella furcifera, both serious resurgence rice pests. JGM exposure significantly increased BPH fecundity and population growth, but suppressed both parameters in laboratory and field WBPH populations. RNAi silencing of Acetyl Co-A carboxylase (Acc), highly expressed in JGM-treated BPH, reduced Acc expression (by > 60%) and eliminated JGM-induced fecundity increases in BPH, but not in EBPH. These findings support our hypothesis that differences in Acc expression separates intraguild species at the molecular level.