Locusts increase carbohydrate consumption to protect against a fungal biopesticide
Locusts increase carbohydrate consumption to protect against a fungal biopesticide
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DOI：
10.1016/j.jinsphys.2014.05.015
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发表时间：
2014-10-01
影响因子：
2.2
通讯作者：
Wilson, Kenneth
中科院分区：
文献类型：
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作者：
Graham, Robert I.;Deacutis, Juliane M.;Wilson, Kenneth
越来越多的证据表明，宿主可以改变其饮食摄入量，以收回对寄生虫和病原体产生有效抵抗力的特定资源。我们研究了大量营养素的摄入和抗病性在澳大利亚蝗灾（Chortoicumberterminifera），挑战与真菌病原体（绿僵菌acridum）的饮食制度不同的蛋白质和可消化的碳水化合物的相对量。膳食蛋白质对免疫功能的影响比碳水化合物更大，表明免疫防御的蛋白质成本高于碳水化合物或总能量成本。然而，由于摄入更多的蛋白质而增加的免疫功能似乎不足以保护蝗虫免受真菌疾病的侵害。我们发现，蝗虫限制饮食高蛋白质（P）和低碳水化合物（C）更容易死于真菌感染比那些限制饮食与低P：C比例。我们假设真菌在利用昆虫血淋巴中的蛋白质方面比宿主在产生免疫效应物方面更有效，从而在高蛋白饮食中有利于病原体的平衡。当允许自由选择时，真菌挑战的幸存者选择了比那些死于感染和那些没有受到真菌蝗虫挑战的人更少的蛋白质丰富的饮食。这些结果是相反的，以前的研究中的毛虫属Spodoptera挑战与细菌和杆状病毒病原体，表明营养摄入和病原体抗性可能是一个复杂的相互作用，具体到不同的宿主物种和疾病的代理。(C)2014爱思唯尔有限公司版权所有。
There is growing evidence to suggest that hosts can alter their dietary intake to recoup the specific resources involved in mounting effective resistance against parasites and pathogens. We examined macronutrient ingestion and disease-resistance in the Australian plague locust (Chortoicetes terminifera), challenged with a fungal pathogen (Metarhizium acridum) under dietary regimes varying in their relative amounts of protein and digestible carbohydrate. Dietary protein influenced constitutive immune function to a greater extent than did carbohydrate, indicating higher protein costs of mounting an immune defence than carbohydrate or overall energy costs. However, it appears that increased immune function, as a result of greater protein ingestion, was not sufficient to protect locusts from fungal disease. We found that locusts restricted to diets high in protein (P) and low in carbohydrate (C) were more likely to die of a fungal infection than those restricted to diets with a low P:C ratio. We hypothesise that the fungus is more efficient at exploiting protein in the insect's haemolymph than the host is at producing immune effectors, tipping the balance in favour of the pathogen on high-protein diets. When allowed free-choice, survivors of a fungus-challenge chose a less-protein-rich diet than those succumbing to infection and those not challenged with fungus locusts. These results are contrary to previous studies on caterpillars in the genus Spodoptera challenged with bacterial and baculoviral pathogens, indicating that nutrient ingestion and pathogen resistance may be a complex interaction specific to different host species and disease agents. (C) 2014 Elsevier Ltd. All rights reserved.