College of Agriculture, Shanxi Agricultural University, Taigu, China.
College of Horticulture, Shanxi Agricultural University, Taigu, China.
J Econ Entomol. 2020 Aug 13;113(4):1972-1981. doi: 10.1093/jee/toaa105.
Insects are ecotothermic organisms. Their development, survival, reproduction as well as distribution and abundance are affected by temperature. Heat shock protein (HSP) gene expression is closely associated with temperature variation and influences the adaptation of organisms to adverse environments. The beetle Agasicles hygrophila has successfully been used for biological control of the invasive plant alligator weed (Alternanthera philoxeroides). As A. hygrophila populations are substantially inhibited by high temperatures in the summer, increasing global temperatures may limit the efficacy of this control agent. We previously established that A. hygrophila eggs have low tolerance to heat and this factored into the decreased numbers of A. hygrophila beetles at temperatures of 37.5°C and above. Here, we identified 26 HSP genes in A. hygrophila and examined the relationship between the transcript levels of these genes and heat tolerance. The temperature at which the expression of these 21 HSP genes peaked (Tpeak) was 37.5°C, which is in line with the limit of the high temperatures that A. hygrophila eggs tolerate. Therefore, we speculate that the Tpeak of HSP gene expression in eggs indicates the upper limit of temperatures that A. hygrophila eggs tolerate. This study identifies HSP genes as potential robust biomarkers and emphasizes that determining species' heat tolerance in their natural habitats remains an important consideration for biocontrol. HSP gene expression data provide information about a species' heat tolerance and may be used to predict its geographical distribution.
昆虫是变温动物。它们的发育、生存、繁殖以及分布和丰度都受到温度的影响。热休克蛋白（HSP）基因表达与温度变化密切相关，影响生物对不利环境的适应。水旱轮作害虫小花蝽（Agasicles hygrophila）已成功用于生物防治入侵植物空心莲子草（Alternanthera philoxeroides）。由于小花蝽种群在夏季会受到高温的严重抑制，全球气温升高可能会限制这种控制剂的效果。我们之前已经确定，小花蝽的卵对热的耐受性较低，这也是在 37.5°C 及以上温度下小花蝽数量减少的原因。在这里，我们在小花蝽中鉴定出 26 个 HSP 基因，并研究了这些基因的转录水平与耐热性之间的关系。这些 21 个 HSP 基因表达的温度峰值（Tpeak）为 37.5°C，这与小花蝽卵能耐受的高温极限一致。因此，我们推测卵中 HSP 基因表达的 Tpeak 表明了小花蝽卵能耐受的温度上限。本研究将 HSP 基因鉴定为潜在的稳健生物标志物，并强调在其自然栖息地确定物种的耐热性仍然是生物防治的一个重要考虑因素。HSP 基因表达数据提供了有关物种耐热性的信息，可用于预测其地理分布。
