Heat hardening capacity in Drosophila melanogaster is life stage specific and juveniles show the highest plasticity

Variations in stress resistance and adaptive plastic responses during ontogeny have rarely been addressed, despite the possibility that differences between life stages can affect species' range margins and thermal tolerance. Here, we assessed the thermal sensitivity and hardening capacity of Drosophila melanogaster across developmental stages from larval to the adult stage. We observed strong differences between life stages in heat resistance, with adults being most heat resistant followed by puparia, pupae and larvae. The impact of heat hardening (1 h at 35°C) on heat resistance changed during ontogeny, with the highest positive effect of hardening observed in puparia and pupae and the lowest in adults. These results suggest that immobile life stages (puparia and pupae) have evolved high plasticity in upper thermal limits whereas adults and larvae rely more on behavioural responses to heat stress allowing them to escape from extreme high temperatures. While most studies on the plastici...尽管生命阶段间的差异可能影响物种的分布范围边界与耐热性，但个体发育过程中的抗逆性及适应性塑性响应变异仍鲜有研究涉及。本研究针对黑腹果蝇（Drosophila melanogaster）从幼虫至成虫的各发育阶段，评估了其热敏感性与热硬化能力。研究观测到不同生命阶段的耐热性存在显著差异：成虫耐热性最强，其次依次为围蛹、蛹与幼虫。热硬化处理（35℃下持续1小时）对耐热性的影响随个体发育进程发生变化，其中围蛹与蛹的硬化正向效应最高，成虫则最低。上述结果表明，静止生命阶段（围蛹与蛹）已演化出较高的高温耐受上限塑性，而成虫与幼虫则更多依赖行为响应应对热胁迫，借此逃离极端高温环境。尽管目前多数针对适应性塑性的研究……