College of Life Sciences, China Jiliang University, 310018 Hangzhou, China;
College of Life Sciences, China Jiliang University, 310018 Hangzhou, China.
Proc Natl Acad Sci U S A. 2018 Jul 17;115(29):7563-7568. doi: 10.1073/pnas.1721473115. Epub 2018 Jul 2.
Food quality is a critical environmental condition that impacts an animal's growth and development. Many insects facing this challenge have evolved a phenotypically plastic, adaptive response. For example, many species of insect exhibit facultative wing growth, which reflects a physiological and evolutionary trade-off between dispersal and reproduction, triggered by environmental conditions. What the environmental cues are and how they are transduced to produce these alternative forms, and their associated ecological shift from dispersal to reproduction, remains an important unsolved problem in evolutionary ecology. In this study, we investigated the role that host quality has on the induction of wing development in a wing polyphenic insect exhibiting strong tradeoffs in investment between dispersal and reproduction, the brown planthopper, a serious rice pest in Asia. As rice plants grow, the short-winged brown planthopper dominates the population, but a shift occurs as the plants mature and senesce in the field such that long-winged brown planthoppers emerge and migrate. It remains unknown how changes in the rice plant induce development of the long-winged morph, despite recent discoveries on the role of the insulin and JNK signaling pathways in wing development. We found that by mimicking the glucose concentration of senescing rice plants, we significantly increased the proportion of long-winged female planthoppers. The effects of glucose on wing morph are additive with previously described effects of density. Our results show that host quality both directly regulates phenotypic plasticity and interacts with other factors such as density to produce the appropriate phenotype for specific environmental conditions.
食品质量是影响动物生长和发育的关键环境条件。许多面临这一挑战的昆虫已经进化出了表型可塑性、适应性反应。例如，许多昆虫物种表现出兼性翅生长，这反映了在环境条件下，扩散和繁殖之间的生理和进化权衡。环境线索是什么，它们如何转化为产生这些替代形式，以及它们从扩散到繁殖的相关生态转变，仍然是进化生态学中一个重要的未解决问题。在这项研究中，我们调查了宿主质量在诱导具有强烈扩散和繁殖投资权衡的多态性昆虫的翅发育中的作用，这种昆虫是一种表现出强烈翅多态性的昆虫，即褐飞虱，它是亚洲一种严重的水稻害虫。随着水稻植株的生长，短翅褐飞虱在种群中占主导地位，但当植株在田间成熟和衰老时，会发生变化，长翅褐飞虱出现并迁移。尽管最近发现胰岛素和 JNK 信号通路在翅发育中的作用，但仍不清楚水稻植株的变化如何诱导长翅形态的发育。我们发现，通过模拟衰老水稻植株的葡萄糖浓度，我们显著增加了长翅雌性褐飞虱的比例。葡萄糖对翅形态的影响与先前描述的密度效应是相加的。我们的结果表明，宿主质量不仅直接调节表型可塑性，还与密度等其他因素相互作用，以产生特定环境条件下的适当表型。
