Sequence analysis, expression profiles and function of thioredoxin 2 and thioredoxin reductase 1 in resistance to nucleopolyhedrovirus in Helicoverpa armigera

Abstract

The thioredoxin system, including NADPH, thioredoxin (Trx), and thioredoxin reductase (TrxR), plays significant roles in maintaining intracellular redox homeostasis and protecting organisms against oxidative damage. In this study, the characteristics and functions of H. armigera HaTrx2 and HaTrxR1 were identified. Sequence analysis showed that HaTrx2 and HaTrxR1 were both highly conserved and shared high sequence identity with other insect counterparts. The mRNA of HaTrx2 was expressed the highest in 5th instar 96 h and was mainly detected in heads and epidermis. The expression of HaTrxR1 was highly concentrated in 5th instar 72 h and 96 h, and higher in malpighian tube, midgut and hemocyte than other examined tissues. HaTrx2 and HaTrxR1 were markedly induced by various types of stress. HaTrx2- or HaTrxR1-knockdown increased ROS production in hemocytes and also increased the lipid damage in NPV infected H. armigera larvae. Furthermore, interference with expression of HaTrx2 or HaTrxR1 transcripts in H. armigera larvae resulted in increased sensitivity to NPV infection and shortened LT50 values. Our findings indicated that HaTrx2 and HaTrxR1 contribute to the susceptibility of H. armigera to NPV and also provided the theoretical basis for the in-depth study of insect thioredoxin system.

TIGAR knockdown radiosensitizes TrxR1-overexpressing glioma in vitro and in vivo via inhibiting Trx1 nuclear transport

“…The dithiol moieties of Trx1 are reduced by receiving electrons from NADPH in the presence of TrxR15. Reduced Trx1 in turn reduces downstream proteins and plays vital roles in regulating cellular redox state, inhibiting apoptosis and increasing the resistance of cancer cells to cytotoxic drugs67. Nevertheless, when Trx1 becomes over-oxidized, the cellular conditions may become more sensitive to oxidative stress and more inclined to apoptosis8.…”

Molecular Identification of Two Thioredoxin Genes From Grapholita molesta and Their Function in Resistance to Emamectin Benzoate

“…Our transcriptional analysis revealed that the GmTrx2 and GmTrx-like1 were expressed at higher levels in the head and salivary glands than other larval tissues. In other insects, BmTrx exhibited higher expression in the fat body and silk gland ( Kim et al, 2007 ); AccTrx1 was mainly expressed in the epidermis ( Yao et al, 2014 ); HaTrx2 gene was expressed at higher levels in the head and epidermis ( Zhang et al, 2015 ). It revealed that the expression of Trx exhibits a tissue-specific pattern.…”

“…The AccTrx1 and AccTrx2 from A. cerana cerana were upregulated by low or high temperatures, H 2 O 2 , and pesticides (acaricide, paraquat, cyhalothrin, and phoxime) treatments ( Yao et al, 2013 , 2014 ). In H. armigera , the transcript of HaTrx2 was significantly stimulated by low or high temperatures, UV light, mechanical injury, microorganism [ E. coli , M. anisopliae , and nucleopolyhedrovirus (NPV)] ( Zhang et al, 2015 ). In this study, GmTrx2 and GmTrx-like1 were obviously induced by 15 and 35°C, E. coli , M. anisopliae , H 2 O 2 , and pesticides-emamectin benzoate treatments, suggesting that GmTrx2 and GmTrx-like1 may play critical roles in resisting oxidative stress caused by these adverse conditions.…”

“…In A. cerana cerana , some Trxs, including AccTrx-like1 , AccTrx1 , and AccTrx2 have been demonstrated to participate in antioxidant defense ( Lu et al, 2012 ; Yao et al, 2013 , 2014 ). In Lepidoptera, SlTrx1 and SlTrx2 from Spodoptera litura and HaTrx2 from Helicoverpa armigera have been identified and demonstrated to participate in antioxidant defense ( Kang et al, 2015 ; Zhang et al, 2015 ). These studies suggested that Trxs play important roles in maintaining redox homeostasis and resisting adverse circumstances in insects.…”

Host miRNAs are involved in hormonal regulation of HaSNPV‐triggered climbing behaviour in Helicoverpa armigera

“…Mock‐infected larvae were fed with an equal amount of sterile water (0 OBs/ml) on artificial diet. Larvae were reared individually in a single glass tube, and after 48 hr, untreated diet was replenished as needed (Zhang, Li et al., ).…”