Work

Cold-tolerant bacteria from alpine Rosaceae plants modulate transcriptional responses of apple and strawberry plantlets to freezing stress

Year: 2026

Type: article

Abstract: Introduction Freezing stress is a frequent challenge in agricultural systems and represents one of the major abiotic constraints on fruit production in Rosaceae crops. Plant-associated microorganisms can support plant survival under cold stress conditions, but little is known about the transcriptional responses stimulated by cold-adapted bacteria in host plants under freezing stress. This study aimed to investigate transcriptional responses activated in apple and strawberry plantlets to freezing stress following the inoculation with two cold-tolerant bacteria isolated from alpine Rosaceae plants. Methods Plantlets were treated with sterile 10 mM MgSO 4 (mock-inoculated) or with a suspension of Pseudomonas GRAN103 (apple) and Duganella ALCN104 (strawberry) and exposed to non-stress (23 ± 1 °C) or freezing stress (-6 ± 0.5 °C for 3 h) conditions. Results Cold-tolerant bacteria isolated from alpine Rosaceae plants decreased electrolyte leakage in apple and strawberry plantlets exposed to freezing stress. Moreover, freezing stress caused distinct transcriptional responses between mock- and bacterium-inoculated plants, as well as between the two crops. In mock-inoculated apple plantlets, freezing stress downregulated transcripts related to amino acid metabolism, lipid metabolism, and secondary metabolism. In contrast, Pseudomonas GRAN103- inoculated apple plantlets upregulated genes involved in amino acid and protein metabolism, hormonal signaling, oxidative stress, secondary metabolism, stress response, and transcription regulation. In strawberry, freezing stress downregulated genes involved in transcription, protein and amino acid metabolism in mock-inoculated plantlets. On the other hand, Duganella ALCN104-inoculated plantlets upregulated pathways associated with lipid metabolism, secondary metabolism, signal transduction, and transport under freezing stress. Discussion The inoculation with Pseudomonas GRAN103 and Duganella ALCN104 reprograms the transcriptional responses of Rosaceae plants to freezing stress, promoting the upregulation of stress-related pathways that may enhance tolerance to freezing stress.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1843975

Authors: Malek Marian, Matteo Buti, Pier Luigi Bianchedi, Ilaria Pertot, Michele Perazzolli

Institutions: University of Trento, University of Florence, Fondazione Edmund Mach

Language: English

Topic: Plant-Microbe Interactions and Immunity

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $3,801