Biology subjects

Pertot, I.

Publications and source records attributed to Pertot, I..

3 recordsLinked to original sources

bioRxiv2026

Endophytic colonization pathways of Pseudomonas chlororaphis M71 and Trichoderma atroviride SC1 in grapevine following stem injection

Endophytic biocontrol agents may contribute to grapevine health, but their ability to establish, persist, and move within woody tissues remains poorly understood. In this study, a stem injection method was developed to introduce Pseudomonas chlororaphis M71 and Trichoderma atroviride SC1 into rooted and grafted grapevine plants, and their spatial and temporal colonization patterns were compared with the movement of a dye tracer. The dye tracer moved rapidly through xylem tissues, whereas both microorganisms showed more restricted early distribution. Over time, M71 and SC1 displayed distinct colonization patterns. M71 persisted after injection, but remained localized near the inoculation site, with limited movement toward roots or distal aerial tissues. In grafted plants, M71 recovery depended on the injection site and declined more markedly after rootstock injection than after scion injection. In contrast, SC1 showed broader and more persistent colonization. In rooted cuttings, SC1 was recovered from stem and root tissues up to 56 days post-injection, and in grafted plants it was recovered across the graft union, particularly after scion injection. Microscopy supported internal localization of both microorganisms. GFP-labelled M71 and SC1 hyphae were observed mainly within xylem vessels, and viable microorganisms were recovered from corresponding wood tissues. No contamination was observed in control plants. These results show that beneficial microorganisms can be introduced into grapevine tissues by stem injection and that bacterial and fungal biocontrol agents differ markedly in their internal movement and persistence. IMPORTANCEIntroducing beneficial microorganisms directly into plant tissues could help in establishing protective endophytic populations, but little is known about how such microorganisms move and persist inside grapevine. This study shows that stem injection can deliver Pseudomonas chlororaphis M71 and Trichoderma atroviride SC1 into grapevine tissues without visible phytotoxicity. The two microorganisms followed different colonization patterns. M71 remained mostly localized near the injection site, whereas SC1 spread more broadly and persisted in both rooted and grafted plants. These findings provide a basis for developing targeted endophytic biocontrol strategies in grapevine propagation and early plant establishment. This approach may be particularly relevant for grapevine trunk diseases and other vascular disorders, in which pathogens colonize internal woody tissues.

microbiology↗

bioRxiv2023

Endophytic bacterial communities of alpine Rosaceae plants are affected by the plant tissue, collection site and host plant and culturable psychrotolerant isolates contribute to plant freezing stress tolerance

O_LIWild plants growing in alpine regions are associated with endophytic microbial communities that may support plant growth and survival under cold conditions. C_LIO_LIThe structure and function of endophytic bacterial communities were characterised in flowers, leaves and roots of three alpine Rosaceous plants in Alpine areas using a combined amplicon sequencing and culture-dependent approach to identify factors shaping these communities. C_LIO_LIAmplicon-sequencing analysis revealed that plant tissue, collection site and host plant are the main factors affecting the richness, diversity and taxonomic structure of endophytic bacterial communities in alpine Rosaceae plants. Core endophytic bacterial taxa were identified as 31 amplicon sequence variants highly prevalent across all plant tissues. C_LIO_LIPsychrotolerant bacterial endophytes belonging to the core taxa of Duganella, Erwinia, Pseudomonas and Rhizobium genera mitigated freezing stress in strawberry plants, demonstrating the beneficial role of endophytic bacterial communities and their potential use for cold stress mitigation in agriculture. C_LI

microbiology↗

bioRxiv2021

Listening to bacterial Esperanto: transcriptome reprogramming in a plant beneficial rhizobacterium

Intraspecies, interspecies and interkingdom signalling occurring via diffusible communication signals (DCSs) continuously shapes the gene expression patterns of individual bacterial species in the rhizosphere, affecting bacterial functions within the rhizosphere microbial community. To unravel how DCSs influence rhizosphere competence of plant beneficial rhizobacteria, we carried out a functional and transcriptome analysis on the plant beneficial bacterium Lysobacter capsici AZ78 (AZ78). Results reveal that 13-methyltetradecanoic acid and indole, glyoxylic acid and 2,3-butanedione play a relevant role in the interaction between L. capsici members and other soil-living (micro)organisms. DCSs regulated mechanisms of multistress and multidrug tolerance and persistence, including detoxification, motility, antibiotic production, and expression of secretion systems. In particular, 13-methyltetradecanoic acid, glyoxylic acid and 2,3-butanedione might enable AZ78 to rapidly colonize the rhizosphere. Moreover, glyoxylic acid and 2,3-butanedione elicit biological responses to outcompete other (micro)organisms. In contrast, indole inactivates twitching motility and antibiotic production. These results demonstrate that DCSs influence the functioning of plant beneficial rhizobacteria and suggest that plant beneficial L. capsici strains could use them to foster rhizosphere colonization and enhance in vivo activities to increase soil health and plant fitness.

microbiology↗