Campbell Stuart A, Halitschke Rayko, Thaler Jennifer S, Kessler André
Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA.
Plant J. 2014 May;78(3):481-90. doi: 10.1111/tpj.12492.
The fitness consequences of mating system variation (e.g. inbreeding) have been studied for at least 200 years, yet the ecological consequences of this variation remain poorly understood. Most plants are capable of inbreeding, and also exhibit a remarkable suite of adaptive phenotypic responses to ecological stresses such as herbivory. We tested the consequences of experimental inbreeding on phenotypic plasticity in resistance and growth (tolerance) traits in Solanum carolinense (Solanaceae). Inbreeding reduced the ability of plants to up-regulate resistance traits following damage. Moreover, inbreeding disrupted growth trait responses to damage, indicating the presence of deleterious mutations at loci regulating growth under stress. Production of the phytohormones abscisic and indole acetic acid, and wounding-induced up-regulation of the defence signalling phytohormone jasmonic acid were all significantly reduced under inbreeding, indicating a phytohormonal basis for inbreeding effects on growth and defence trait regulation. We conclude that the plasticity of induced responses is negatively affected by inbreeding, with implications for fragmented populations facing mate limitation and stress as a consequence of environmental change.
交配系统变异（如近亲繁殖）对适合度的影响已被研究了至少200年，但这种变异的生态后果仍知之甚少。大多数植物都能够进行近亲繁殖，并且还表现出一系列对诸如食草等生态胁迫的适应性表型反应。我们测试了实验性近亲繁殖对卡罗来纳茄（茄科）抗性和生长（耐受性）性状表型可塑性的影响。近亲繁殖降低了植物在受到损害后上调抗性性状的能力。此外，近亲繁殖扰乱了生长性状对损害的反应，表明在调控胁迫下生长的基因座上存在有害突变。在近亲繁殖条件下，植物激素脱落酸和吲哚乙酸的产生以及伤口诱导的防御信号激素茉莉酸的上调均显著降低，这表明近亲繁殖对生长和防御性状调控的影响存在植物激素基础。我们得出结论，诱导反应的可塑性受到近亲繁殖的负面影响，这对因环境变化而面临配偶限制和胁迫的碎片化种群具有重要意义。
