Why is living fast dangerous? Disentangling the roles of resistance and tolerance of disease

Primary axes of host developmental tempo (HDT; e.g., large-small body size continuum; slow-quick return leaf continuum) represent latent biological processes and are increasingly used to a priori identify hosts that contribute disproportionately more to pathogen transmission. HDT's influence on host contributions to transmission depends on how HDT influences both resistance and tolerance of disease. Here, we use structural equation modeling to address known limitations of conventional measures of resistance and tolerance. We first provide a general 'resistance-tolerance' meta-model, from which system-specific models can be derived. We then develop a model specific to a group of vector-transmitted viruses that infect hundreds of grass species worldwide. We tested the model using experimental inoculations of six phylogenetically paired grass species. We found 1) host traits covaried according to a prominent HDT axis, the slow-quick continuum; 2) infection caused a greater reduction in the...

宿主发育节奏（Host Developmental Tempo, HDT）的核心轴，例如体型大小连续谱、叶片快慢周转连续谱，代表着潜在的生物学过程，如今正日益被用于先验识别对病原体传播贡献不成比例的宿主。HDT对宿主传播贡献的调控效应，取决于其如何同时作用于宿主的抗病性与耐病性。本研究采用结构方程模型（Structural Equation Modeling），以克服传统抗病性、耐病性测量方法的已知局限。我们首先构建了通用的“抗病性-耐病性”元模型，据此可衍生出针对特定研究系统的专属模型；随后针对一类可感染全球数百种草本植物的媒介传播病毒开发了专属模型。我们通过对6对系统发育配对的草本物种开展人工接种实验对该模型进行了验证，结果发现：1）宿主性状按照核心HDT轴——快慢连续谱发生共变异；2）感染导致了更为显著的[原文未完整表述，保留省略]