title: Burkholderia phytofirmans PsJN primes Vitis vinifera L. and confers a better tolerance to low nonfreezing temperatures.
abstract: Several endophytic bacteria reportedly induce resistance to biotic stress and abiotic stress tolerance in several plant species. Burkholderia phytofirmans PsJN is a plant-growth-promoting rhizobacterium (PGPR) that is able to colonize grapevine tissues and induce resistance to gray mold. Further, PsJN induces physiological changes that increase grapevine tolerance to low nonfreezing temperatures. To better understand how bacteria induced the observed phenomena, stress-related gene expression and metabolite accumulation were monitored in 6-week-old Chardonnay grapevine plantlets after exposure to low nonfreezing temperatures. Under normal conditions (26°C), plantlet bacterization had no significant effect on the monitored parameters. By contrast, at 4°C, both stress-related gene transcripts and metabolite levels increased earlier and faster, and reached higher levels in PsJN-bacterized plantlets than in nonbacterized counterparts, in accordance with priming phenomena. The recorded changes may be correlated with the tolerance to cold stress conferred by the presence of PsJN. This is the first time that PGPR-induced priming has been shown to protect plants against low-temperature stress. Moreover, 1 week after cold exposure, levels of stress-related metabolites had declined more in PsJN-bacterized plants, suggesting that the endophyte is involved in the cold acclimation process via the scavenging system.
authors.affiliation: Universite de Reims Champagne-Ardenne, Unite de Recherche Vignes et Vins de Champagne, Reims Cedex, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Theocharis
authors.forename: Sophie
authors.initials: S
authors.lastname: Bordiec
authors.forename: Olivier
authors.initials: O
authors.lastname: Fernandez
authors.forename: Sandra
authors.initials: S
authors.lastname: Paquis
authors.forename: Sandrine
authors.initials: S
authors.lastname: Dhondt-Cordelier
authors.forename: Fabienne
authors.initials: F
authors.lastname: Baillieul
authors.forename: Christophe
authors.initials: C
authors.lastname: Clément
authors.forename: Essaïd Ait
authors.initials: EA
authors.lastname: Barka
mesh_terms: D000064:Acclimatization; D000447:Aldehydes / Q000032:analysis / Q000378:metabolism; D001422:Bacterial Adhesion; D019117:Burkholderia / Q000235:genetics / Q000502:physiology*; D003080:Cold Temperature; D060026:Endophytes; D017343:Genes, Plant / Q000235:genetics*; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D008315:Malondialdehyde / Q000032:analysis / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology; D011392:Proline / Q000032:analysis / Q000378:metabolism; D013559:Symbiosis; D013997:Time Factors; D027843:Vitis / Q000235:genetics / Q000382:microbiology* / Q000502:physiology*
chemical_list: D000447:Aldehydes; D008315:Malondialdehyde; D011392:Proline; D006861:Hydrogen Peroxide