Juurakko Collin L, diCenzo George C, Walker Virginia K
Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada.
Department of Biomedical and Molecular Sciences, School of Environmental Studies, Queen's University, Kingston, ON K7L 3N6, Canada.
Plants (Basel). 2021 Dec 20;10(12):2824. doi: 10.3390/plants10122824.
Shifts in microbiota undoubtedly support host plants faced with abiotic stress, including low temperatures. Cold-resistant perennials prepare for freeze stress during a period of cold acclimation that can be mimicked by transfer from growing conditions to a reduced photoperiod and a temperature of 4 °C for 2-6 days. After cold acclimation, the model cereal, , was characterized using metagenomics supplemented with amplicon sequencing (16S ribosomal RNA gene fragments and an internal transcribed spacer region). The bacterial and fungal rhizosphere remained largely unchanged from that of non-acclimated plants. However, leaf samples representing bacterial and fungal communities of the endo- and phyllospheres significantly changed. For example, a plant-beneficial bacterium, sp. M2, increased more than 200-fold in relative abundance in cold-acclimated leaves, and this increase correlated with a striking decrease in the abundance of (from 8% to zero). This change is of consequence to the host, since is a ubiquitous ice-nucleating phytopathogen responsible for devastating frost events in crops. We posit that a responsive above-ground bacterial and fungal community interacts with 's low temperature and anti-pathogen signalling networks to help ensure survival in subsequent freeze events, underscoring the importance of inter-kingdom partnerships in the response to cold stress.
微生物群的变化无疑有助于宿主植物应对包括低温在内的非生物胁迫。耐寒多年生植物在冷驯化期间为冻害做准备，冷驯化可以通过将植物从生长条件转移到较短光周期和4°C温度下2 - 6天来模拟。冷驯化后，使用宏基因组学并辅以扩增子测序（16S核糖体RNA基因片段和一个内转录间隔区）对模式谷物进行了表征。细菌和真菌根际与未驯化植物相比基本保持不变。然而，代表叶内和叶际细菌和真菌群落的叶片样本发生了显著变化。例如，一种对植物有益的细菌，M2菌属，在冷驯化叶片中的相对丰度增加了200多倍，这种增加与另一种菌（从8%降至零）丰度的显著下降相关。这种变化对宿主有重要影响，因为该菌是一种普遍存在的冰核植物病原体，会导致作物遭受毁灭性的霜冻事件。我们认为，一个有响应的地上细菌和真菌群落与植物的低温和抗病原体信号网络相互作用，以帮助确保在随后的冻害事件中存活，这突出了跨王国伙伴关系在应对冷胁迫中的重要性。
