Korves Tonia M, Bergelson Joy
Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA.
Plant Physiol. 2003 Sep;133(1):339-47. doi: 10.1104/pp.103.027094.
We present evidence that susceptible Arabidopsis plants accelerate their reproductive development and alter their shoot architecture in response to three different pathogen species. We infected 2-week-old Arabidopsis seedlings with two bacterial pathogens, Pseudomonas syringae and Xanthomonas campestris, and an oomycete, Peronospora parasitica. Infection with each of the three pathogens reduced time to flowering and the number of aerial branches on the primary inflorescence. In the absence of competition, P. syringae and P. parasitica infection also increased basal branch development. Flowering time and branch responses were affected by the amount of pathogen present. Large amounts of pathogen caused the most dramatic changes in the number of branches on the primary inflorescence, but small amounts of P. syringae caused the fastest flowering and the production of the most basal branches. RPS2 resistance prevented large changes in development when it prevented visible disease symptoms but not at high pathogen doses and when substantial visible hypersensitive response occurred. These experiments indicate that phylogenetically disparate pathogens cause similar changes in the development of susceptible Arabidopsis. We propose that these changes in flowering time and branch architecture constitute a general developmental response to pathogen infection that may affect tolerance of and/or resistance to disease.
我们提供的证据表明，易受感染的拟南芥植株会加速其生殖发育，并改变其地上部结构，以应对三种不同的病原体。我们用两种细菌病原体丁香假单胞菌和野油菜黄单胞菌以及一种卵菌寄生霜霉感染了两周大的拟南芥幼苗。感染这三种病原体中的任何一种都会缩短开花时间，并减少主花序上的地上分枝数量。在没有竞争的情况下，丁香假单胞菌和寄生霜霉感染还会增加基部枝条的发育。开花时间和分枝反应受病原体数量的影响。大量病原体导致主花序上的分枝数量发生最显著的变化，但少量的丁香假单胞菌会导致最快的开花和最多的基部枝条产生。当RPS2抗性阻止可见病害症状时，它会阻止发育的大变化，但在高病原体剂量以及发生大量可见过敏反应时则不会。这些实验表明，系统发育上不同的病原体在易感拟南芥的发育过程中会引起类似的变化。我们提出，开花时间和分枝结构的这些变化构成了对病原体感染的一种普遍发育反应，可能会影响对疾病的耐受性和/或抗性。
