Cloning and functional analysis of the Hyphantria cunea glutathione-S-transferase gene, HcGST-E1
Author of the article:GAO Lin-Na, CHEN Qi-Yu, MENG Xiang, CHEN Min
Author's Workplace：Beijing Key Laboratory of Forest Prepest Control, Beijing Forestry University, Beijing 100083, China
Key Words：Hyphantria cunea; glutathione-S-transferase; HcGST-E1; RNAi; quercetin
Abstract：
[Objectives] To clone the Hyphantria cunea glutathione S-transferases (GST) gene (HcGST-E1 ) and verify the role of this gene in the response of H. cunea to quercetin, a common secondary substance in host plants. [Methods] HcGST-E1 was cloned based on the quercetin-induced midgut transcriptome of H. cunea and real-time, quantitative PCR results. The gene was then silenced using RNAi technology and the effect of this on the weight and survival of quercetin-treated 4th instar larvae investigated. [Results] The HcGST-E1 was successfully cloned and silenced. dsHcGST-E1 effectively inhibited the expression of HcGST-E1 with a maximum silencing efficiency of 62.3%. Over the same period of time, 1 000 ng of dsHcGST-E1 was more effective than 500 ng dsHcGST-E1. The survival rates of HcGST-E1 silenced larvae that had been fed an artificial diet containing either 0.5% or 1.0% quercetin were 40.00% and 33.33%, respectively, significantly lower than their respective control groups（73.33% and 66.67%; P < 0.05）or blank control groups（86.67% and 80.00%; P < 0.05）. The body weight of HcGST-E1 silenced H. cunea larvae did not fluctuate significantly, and their weight was lower than that of larvae in both respective, and blank, control groups. Larvae in the 5% quercetin treatment group were not significantly lighter than those in the respective control group, but were significantly lighter than those in the blank control groups on day 6 (P < 0.01). Similarly, larvae in the 1.0% quercetin treatment group were not significantly lighter than those in the respective control group, but were significantly lighter than those in the blank control groups on days 4 and 6 (P <0.05). [Conclusion] Silencing the HcGST-E1 gene increased the susceptibility of H. cunea larvae to quercetin, retarding their growth and development. This indicates that HcGST-E1 plays a role in the detoxification and metabolization of quercetin. These results provide a basis for further research on the role of GST genes in the resistance of H. cunea to plant secondary compounds.