Zhang Lingling, Zhang Xiaojuan, Batool Khadija, Hu Xiaohua, Chen Mingfeng, Xu Jin, Wang Junxiang, Pan Xiaohong, Huang Tianpei, Xu Lei, Yu Xiao-Qiang, Guan Xiong
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & School of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, People's Republic of China.
Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou 350002, Fujian, People's Republic of China.
J Med Entomol. 2018 Jan 10;55(1):210-216. doi: 10.1093/jme/tjx192.
Bacillus thuringiensis (Bt) is one of the most widely used and studied biopesticides. However, it is vulnerable to the influence of ultraviolet (UV) radiation, causing shorter persistence under field conditions. To obtain a high-active and effective Bt new product, the main objective of this study is to obtain a highly UV-resistant Bt mutant from the mosquitocidal Bt LLP29 through UV exposure. After 19 rounds of UV exposure, a Bt mutant named LLP29-M19 was obtained, showing resistance to UV radiation for up to 67 min. The mosquitocidal fatality rate of LLP29-M19 was 95%, which was slightly higher than that of LLP29 (90%). Comparative characterization showed that there were no substantial differences in morphology between LLP29-M19 and the original strain, LLP29. However, some changes were detected in physiological and biochemical characteristic reactions, including fructose, glucose, and xylose metabolism. Furthermore, although both LLP29-M19 and LLP29 showed negative zeta potentials, the surface charge of LLP29 was -28.1 mV and that of LLP29-M19 was -42.8 mV. The size distribution of LLP29-M19 was also slightly larger than that of LLP29. Fourier transform infrared analysis indicated that amide functional groups might be involved in the resistance mechanism of LLP29-M19. Quantitative analysis using inductive coupled plasma emission spectrometry showed that some elements increased greatly in LLP29-M19, such as K. All of these results will be highly valuable for better understanding the mechanism of Bt resistance. Explanations regarding the resistance mechanism of this novel Bt mutant may lead to the development of new biopesticides with high mosquitocidal activity and persistence.
苏云金芽孢杆菌（Bt）是使用最广泛且研究最多的生物农药之一。然而，它易受紫外线（UV）辐射的影响，导致其在田间条件下持效期较短。为获得一种高活性且有效的Bt新产品，本研究的主要目的是通过紫外线照射从杀蚊Bt LLP29中获得一种高度抗紫外线的Bt突变体。经过19轮紫外线照射后，获得了一个名为LLP29 - M19的Bt突变体，其对紫外线辐射的抗性长达67分钟。LLP29 - M19的杀蚊致死率为95%，略高于LLP29（90%）。比较特征表明，LLP29 - M19与原始菌株LLP29在形态上没有实质性差异。然而，在生理和生化特征反应中检测到了一些变化，包括果糖、葡萄糖和木糖代谢。此外，尽管LLP29 - M19和LLP29的ζ电位均为负，但LLP29的表面电荷为 - 28.1 mV，而LLP29 - M19的表面电荷为 - 42.8 mV。LLP29 - M19的粒径分布也略大于LLP29。傅里叶变换红外分析表明，酰胺官能团可能参与了LLP29 - M19的抗性机制。使用电感耦合等离子体发射光谱法进行的定量分析表明，LLP29 - M19中一些元素大幅增加，如钾。所有这些结果对于更好地理解Bt抗性机制具有很高的价值。关于这种新型Bt突变体抗性机制的解释可能会导致开发出具有高杀蚊活性和持效性的新型生物农药。
