Effect of body lipid content is linked to nutritional adaptation in the acclimation responses of mesic-adapted Paederus to seasonal variations in desiccation stress
Effect of body lipid content is linked to nutritional adaptation in the acclimation responses of mesic-adapted Paederus to seasonal variations in desiccation stress
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DOI：
10.1016/j.jinsphys.2021.104226
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发表时间：
2021-03-24
影响因子：
2.2
通讯作者：
Neoh, Kok-Boon
中科院分区：
文献类型：
--
作者：
Bong, Lee-Jin;Wang, Chia-Yu;Neoh, Kok-Boon
干燥应激会导致适应中湿的节肢动物失去体内水分。然而，适应中等气候的隐翅虫可以在干燥的田地条件下存活很长时间，这表明这些甲虫采用了一系列的水源保护机制。我们在 14 个月的采样期内调查了现场采集的隐翅虫成虫的水平衡机制。我们还通过稳定同位素分析检查他们的饮食来评估他们的营养适应情况。甲虫的失水率（WLR）与水稻作物周期和饱和度赤字显着相关。成年甲虫的角质层通透性（CP）维持在<30μg·cm·2h(-1)mmHg(-1)；然而，CP随着WLR的增加而显着增加。这一结果表明 CP 可能在减少甲虫过度失水方面发挥次要作用。当 WLR 高时，甲虫的身体含水量和身体含水量百分比增加。海藻糖、葡萄糖和糖原似乎在增强昆虫的水分储备方面没有发挥核心作用。体内脂质含量范围为 0.22 +/- 0.06 至 0.87 +/- 0.07 mg，与 WLR 呈负相关。这种关联表明内部代谢水的增加是由脂质分解代谢介导的。稳定同位素分析结果表明，当饱和度赤字增加并且相关的 WLR 达到峰值时，隐翅虫将其饮食转向富含碳水化合物的植物。否则，它们会消耗大量缺乏主食碳水化合物的草食动物猎物。通过季节性饮食变化以脂质形式积累能量储备可能会对适应中度的隐翅虫的生存和种群成功产生重大影响。
Desiccation stress causes mesic-adapted arthropods to lose their body water content. However, mesic-adapted Paederus beetles can survive over prolonged periods under dry field conditions, suggesting that these beetles adopt an array of water conservation mechanisms. We investigated the water balance mechanisms of field-collected Paederus adults over a 14-month sampling period. We also assessed their nutritional adaptations by performing a stable isotope analysis to examine their diet. The water loss rate (WLR) of the beetles was significantly associated with the rice crop cycle and saturation deficit. The cuticular permeability (CP) of adult beetles was maintained at < 30 mu g cm 2h(-1) mmHg(-1); however, CP increased significantly with the WLR. This result indicates that CP might play a minor role in reducing excessive water loss in beetles. The beetles' body water content and percentage total body water content increased when the WLR was high. Trehalose, glucose, and glycogen did not appear to play a central role in enhancing the water reserves in the insects. The body lipid content ranged from 0.22 +/- 0.06 to 0.87 +/- 0.07 mg and was negatively associated with the WLR. This association indicates that the increase in internal metabolic water was mediated by lipid catabolism. Stable isotope analysis results revealed that the Paederus beetles shifted their diet to carbohydrate-rich plants when the saturation deficit increased and the associated WLR reached its peak; otherwise, they consumed a high amount of staple carbohydrate-poor herbivore prey. The accumulation of energy reserves in the form of lipids through seasonal dietary shifts may exert major effects on the survival and population success of mesic-adapted Paederus beetles.