The Effect Of UVA Radiation On The Cu/ZnSOD,MnSOD And GST Gene Expression Of Helicoverpa Armigera

Phototaxis is a one of the main tendency for many nocturnal insects, and it has been investigated by a large number of researchers at home and abroad, but there is no reazonable explanation accepted for phototaxis at present. Thus, reveal the internal mechanism of phototaxis is conducive to guide the agricultural practices and improve the light trapping effect of the pest. The cotton bollworm, Helicoverpa armigera, is a serious crop pest in China and neighboring countries, and this nocturnal insect display a conspicuous positive phototactic behavior to light stimuli, especially sensitive to UV light. It has reported that it can cause oxidative stress when the insects was stimulated by UV light, and direct effects of UV upon insect behavior and biochemistry have been reported. According to the characteristicsof this study, partical Cu/ZnSOD gene sequence of Helicoverpa armigera was cloned by PCR amplification, and the sequence was analysised. By semi-quantitative PCR, the effect of UVA stimuli to Helicoverpa armigera at different times, the different expression of Cu/ZnSOD,MnSOD and GST gene was investigated, the main results are as follows:(1) This experiment cloned partical of Helicoverpa armigera Cu/ZnSOD gene cDNA sequence by RT-PCR firstly. Compared with other species, this gene shows conserved structural features. The evolutionary analysis shows that homology identities between Spodoptera exigua,Antheraea pernyi,Hyphantria cunea,Bombyx mori,Drosophila melanogaster and Aedes aeqypti are 79%,75%,74%,74%,72%,70%, respectively.(2) The expression of Cu/ZnSOD gene after 15min of UVA radiation was significant higher than control level. Grayscale value analysis showed that treatment group of male 2.52 times the control group, and female 2.93 times the control group. It is indicated that UVAcan cause the Cu/ZnSOD gene upregulated in response to oxidative stress generated by excesssive free radicals.(3) There is no significant difference of MnSOD gene expression between the treatment group and control group after the UVA radiation stimulated different times on male and female. Grayscale value analysis showed that treatment group of male 0.97 times the control group, and female 1.13 times the control group. So MnSOD is not response to oxidative stress.(4) The expression of GST gene after 15min of UVA radiation was significant higher than control level. Grayscale value analysis showed that treatment group of male 1.74 times the control group, and female 3.10 times the control group. It is indicated that GST can play a significant role in the process of oxidative stress, and the level of GST gene expression in females Helicoverpa armigera adult is higher than males.