Physiological Responses Reveal the Adaptability of Different Body Colors in Tuss Ah (antheraea Pernyi ) under Extreme Heat Stress

Abstract Background The tussah (Antheraea pernyi ) is an important silk-producing economic insect that needs to be reared in the wild. High temperature is a severe environmental factor affecting growth and reducing yield. Differentbody color species of A. pernyi present latitudinal distribution, and the reasons are still poorly understood. Therefore, this study was undertaken on the adaptability of different body colors of A. pernyi in response to extreme thermal temperatures, by detecting the expression of heat shock protein 70 (HSP70) and level of Superoxide dismutase (SOD) and (Catalase) CAT enzyme activities could display differences in different body color species. Results This study revealed that 1. The highest SOD enzyme activity was observed in green-yellow species(Liao Can 527), and the enzyme activity was relatively lowest in yellow species (Fang shan huang). The SOD enzyme activities of the three species revealed remarkable differences after 1 h of heat shock(p<0.05). 2. The highest CAT enzyme activity was observed in green species(Ji qing), three species exhibited significant differences in CAT enzyme activity at 3 h(p<0.05), but the CAT enzyme activity was relatively low in the hemolymph. 3. The mRNA expression levels of HSP70 in the three species elevated to a maximum after 1 h of treatment and then gradually down-regulated. The HSP70 expression of green species was lowest and yellow species was highest in response to exposure to the thermal environment. The expression levels of HSP70 were significantly different among the three species at 2 h after treatment. The findings trending towards that SOD and CAT enzyme activities both showed an increasing trend followed by a decrease were subjected to acute thermal challenge and levels of HSP70 expression presented a decreasing pattern. Correlation analysis revealed that SOD activity was negatively correlated with time, and HSP70 expression presented species dependence. Conclusion These achievements provide evidence that differences in heat resistance of different body colors A. pernyi. Yellow body color is more heat resistant and conforms to low-latitude adaptability, other body colors are relatively weak. In addition, the SOD enzyme activity and HSP70 gene expression of A. pernyiare advantageous in assessing the resistance of species.