Exploring the functional potential of plant-associated microbiomes in alpine region to enhance cold stress tolerance in plants

• Main Authors: Marian, Malek, Milanese, Irma, Antonielli, Livio, Perazzolli, Michele
• Format: Conference Object
• Language: English
• Published: 2022
• Subjects: Plant Microbiome; Alpine Region; Cold Stress; Rosaceae Plants; Psychrotolerant Bacteria; Plant Growth Promotion; Dryas octopetala
• Online Access: https://zenodo.org/record/6850915; https://doi.org/10.5281/zenodo.6850915

Climate change-associated extreme weather events such as early spring frosts have increased in frequency and intensity over the past decades. Cold stress is one of the main limiting factors for fruit crop production worldwide. Plants and their associated microbial communities have developed complex adaptation strategies against cold stress. Plants growing in cold regions, such as alpine regions, are hypothesized to survive cold stress thanks to symbiosis with endophytic microorganisms. However, the structure and function of endophytic microbial communities associated with such plants are poorly understood. Our aim is to taxonomically and functionally characterize the endophytic bacterial communities associated with three wild cold-adapted Rosaceae plants (i.e. Geum montanum, Alchemilla sp., and Dryas octopetala) from alpine region. Plant samples were collected from seven different sites in Italy from two expositions (North and South). The bacterial community structure associated with the flowers, leaves, and roots were characterized using 16S rRNA gene (V5–V7 region) amplicon sequencing to identify potential candidate taxa for cold tolerance. In addition, targeted isolation methods were used to recover culturable psychrotolerant bacterial taxa through a combination of a low nutrient medium (Reasoner's 2A agar), long incubation time (up to 4 weeks) and low temperature (at 4°C). Plant species, tissues, and sites were the main factors influencing bacterial richness, diversity, and community structure. Furthermore, we established a taxonomically diverse psychrotolerant bacterial culture collections (about 700 isolates belonging to 54 different genera) representing the majority of dominant genera detectable by culture-independent community profiling, including Pseudomonas, Erwinia, Sphingomonas, Rhizobium, Massilia, Janthinobacterium, Duganella, Flavobacterium, Mucilaginibacter, Subtercola, and Galbitalea. This study contributes to the understanding of plant-associated microbiomes in alpine regions, and highlight ...