Molecular identification of a thioredoxin-like gene in Helicoverpa armigera and its expression following different kinds of stress

Author of the article:ZHANG Song-Dou** ZHANG Bo-Yu SHEN Zhong-Jian LIU Yan-Jun LI Zhen ZHANG Qing-Wen LIU Xiao-Xia***

Author's Workplace：Department of Entomology, China Agricultural University, Beijing 100193, China

Key Words：Helicoverpa armigera, thioredoxin-like, molecular cloning, temporal-spatial expression, adversity treatment

Abstract：To clone the full-length cDNA of a thioredoxin-like (HaTrx-like) gene in Helicoverpa armigera, to analyze its spatio-temporal distribution in different developmental stages and different tissues, and to determine its expression patterns following mechanical injury, exposure to UV radiation and extreme temperatures. [Methods]  The full-length cDNA of HaTrx-like gene was amplified using the RT-PCR method and further validated by sequencing. The gene and protein sequences of HaTrx-like were analyzed with several kinds of bioinformatics software. The spatio-temporal distribution of HaTrx-like and its expression patterns after the different stress treatments were determined by qRT-PCR. [Results]  The full-length cDNA of HaTrx-like was 526 bp and contained a 381 bp ORF encoding a 126-residue amino acid sequence. Sequence analysis indicates that HaTrx-like shares high sequence identity with its counterpart in other insects and contains a highly conserved CXXC active site in the N-terminal. The results of temporal transcript profiling indicate that HaTrx-like was more highly expressed in the 0 h and 96 h of the 5th instar, on the first and fifth day of the pupal, and on the first day of the adult, life stages. Spatial expression profiling shows that the gene was mainly expressed in the midgut and malpighian tubules of larvae, and in the muscles of adults. Meanwhile, the transcription of HaTrx-like was obviously induced by mechanical injury, ultraviolet light, cold (0°C), or high (37°C), temperatures. [Conclusion]  The full-length cDNA of HaTrx-like gene was successfully cloned and preliminarily identified as a member of the thioredoxin family. Its expression is significantly upregulated by different kinds of stress. These results will contribute to further studies on the features and functions of insect thioredoxin.