Cold Acclimation in Brachypodium Is Accompanied by Changes in Above-Ground Bacterial and Fungal Communities

• Published in: Plants (Basel) Vol. 10; no. 12; p. 2824
• Main Authors: Juurakko, Collin L, diCenzo, George C, Walker, Virginia K
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20.12.2021; MDPI
• Subjects: Acclimation; Acclimatization; amplicon and shotgun sequencing; Bacteria; Brachypodium; Brachypodium distachyon; Cold; Cold acclimation; Fungi; Gene sequencing; Grasses; Host plants; Leaves; Low temperature; Low temperature resistance; Metagenomics; microbiome; Microbiota; Mitochondrial DNA; Plant bacterial diseases; Proteins; Pseudomonas; Relative abundance; Rhizosphere; rRNA 16S; Seeds; Soils; Spacer region; Canada; United States > US; Germany; amplicon and shotgun sequencing; Brachypodium distachyon; metagenomics; Streptomyces; cold acclimation; Pseudomonas; microbiome
• ISSN: 2223-7747; 2223-7747
• 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.