Enhancement of Chilling Resistance of Inoculated Grapevine Plantlets with a Plant Growth-Promoting Rhizobacterium,Burkholderia phytofirmansStrain PsJN

Abstract

In vitro inoculation of Vitis vinifera L. cv. Chardonnay explants with a plant growth-promoting rhizobacterium, Burkholderia phytofirmans strain PsJN, increased grapevine growth and physiological activity at a low temperature. There was a relationship between endophytic bacterial colonization of the grapevine plantlets and their growth at both ambient (26°C) and low (4°C) temperatures and their sensitivities to chilling. The major benefits of bacterization were observed on root growth (11.8-and 10.7-fold increases at 26°C and 4°C, respectively) and plantlet biomass (6-and 2.2-fold increases at 26°C and 4°C, respectively). The inoculation with PsJN also significantly improved plantlet cold tolerance compared to that of the nonbacterized control. In nonchilled plantlets, bacterization enhanced CO 2 fixation and O 2 evolution 1.3 and 2.2 times, respectively. The nonbacterized controls were more sensitive to exposure to low temperatures than were the bacterized plantlets, as indicated by several measured parameters. Moreover, relative to the noninoculated controls, bacterized plantlets had significantly increased levels of starch, proline, and phenolics. These increases correlated with the enhancement of cold tolerance of the grapevine plantlets. In summary, B. phytofirmans strain PsJN inoculation stimulates grapevine growth and improves its ability to withstand cold stress.

Heavy metal tolerant Pseudomonas protegens isolates from agricultural well water in northeastern Algeria with plant growth promoting, insecticidal and antifungal activities

“…In addition, insecticidal activities were reported for some PGPB in addition to the existing biocontrol repertoire with perspectives for application against insect crop pests [48]. Recent reports suggest that PGPB also enhance the tolerance of plants towards abiotic stresses such as drought [54,58], chilling injury [3], salinity [22], metal toxicity [13] and elevated temperature stress [1,2].…”

Effectiveness of Azospirillum brasilense Sp245 on young plants of Vitis vinifera L.

“…The augmented content of total phenols in roots of treated cuttings is of notable importance considering the prominent role of these compounds in the enhancement of plant defence [10,28,29]. Several authors have reported the effects of systemic resistance induced through PGPRs in different crops, including grapevines, and it has been associated with the enhancement of plant defence.…”

“…The root biomass was evaluated by fresh and dry weight (held at 65°C until reaching constant weight). Moreover, samples of roots were processed in order to determine the content of: total phenolic compounds in fresh material (0.6 g), according to Ait Barka et al [10]; content of main mineral macro-elements (N, P, K) and the micro-element Fe in ashes (0.5 g of dried material heated to 600°C for 14 hours), according to Sabir et al [7]. Chemical analyses were performed at least in triplicate both in control and treated cuttings.…”

Can microbes help crops cope with climate change?

“…Last decade saw an explosion of publications reporting the benefi cial effects of microorganisms such as Pseudomonas, Bacillus, Arthrobacter, Pantoea, Burkholderia, Rhizobium etc. in enhancing the tolerance of crops such as sunfl ower, maize, wheat, chickpea, groundnut, spices and grapes to drought, salinity, heat stress and chilling injury under controlled conditions [3,4]. The introduced microorganisms in the rhizosphere enhance soil aggregation by production of EPS thereby improving the water availability to plants during dry periods [5], induce the synthesis of heat shock proteins and osmoregulants such as proline, glycine betaine, help in maintenance of cell membrane integrity [6], all of which contribute to improved stress tolerance in plants.…”