Department of Plant Biology, University of California-Davis, Davis, California, United States of America.
Department of Agriculture, Arkansas State University, Jonesboro, Arkansas, United States of America.
PLoS Biol. 2018 Feb 23;16(2):e2003862. doi: 10.1371/journal.pbio.2003862. eCollection 2018 Feb.
Bacterial communities associated with roots impact the health and nutrition of the host plant. The dynamics of these microbial assemblies over the plant life cycle are, however, not well understood. Here, we use dense temporal sampling of 1,510 samples from root spatial compartments to characterize the bacterial and archaeal components of the root-associated microbiota of field grown rice (Oryza sativa) over the course of 3 consecutive growing seasons, as well as 2 sites in diverse geographic regions. The root microbiota was found to be highly dynamic during the vegetative phase of plant growth and then stabilized compositionally for the remainder of the life cycle. Bacterial and archaeal taxa conserved between field sites were defined as predictive features of rice plant age by modeling using a random forest approach. The age-prediction models revealed that drought-stressed plants have developmentally immature microbiota compared to unstressed plants. Further, by using genotypes with varying developmental rates, we show that shifts in the microbiome are correlated with rates of developmental transitions rather than age alone, such that different microbiota compositions reflect juvenile and adult life stages. These results suggest a model for successional dynamics of the root-associated microbiota over the plant life cycle.
与根系相关的细菌群落会影响宿主植物的健康和营养。然而，人们对这些微生物组合在植物整个生命周期中的动态变化还了解甚少。在这里，我们使用密集的时间采样，从根系空间隔室中采集了 1510 个样本，用于描述在 3 个连续生长季节以及在不同地理区域的 2 个地点中，田间生长的水稻（Oryza sativa）根系相关微生物组的细菌和古菌成分。结果发现，在植物生长的营养阶段，根系微生物组高度动态，然后在生命周期的其余时间稳定下来。通过使用随机森林方法进行建模，将田间地点之间保守的细菌和古菌分类群定义为水稻植物年龄的预测特征。年龄预测模型表明，与未受胁迫的植物相比，干旱胁迫的植物具有发育不成熟的微生物组。此外，通过使用具有不同发育速度的基因型，我们表明微生物组的变化与发育转变的速度相关，而不仅仅与年龄相关，因此不同的微生物组组成反映了幼年和成年阶段。这些结果提出了一个关于植物生命周期中根系相关微生物组演替动态的模型。
