Choline–betaine pathway contributes to hyperosmotic stress and subsequent lethal stress resistance in Pseudomonas protegens SN15-2

Springer Science and Business Media LLC - Tập 45 - Trang 1-10 - 2020
Danyan Tang1, Xiaobing Wang1, Jian Wang1, Mengfei Wang1, Yaping Wang1, Wei Wang1
1State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China

Tóm tắt

Pseudomonas protegens SN15-2, a typical non-spore-forming rhizosphere bacterium, has excellent biocontrol capabilities; thus, it is necessary to explore the stress resistance of SN15-2. The choline–glycine betaine pathway is considered as an important mechanism by which bacteria adapt to stressful environments. In this work, we demonstrated that the expression of the betA and betB genes, which are involved in the choline–glycine betaine pathway in SN15-2, was highly increased by 12-fold and 26-fold, respectively, by hyperosmotic stress and choline treatment. The accumulation of betaine in SN15-2 (5.54 g/L) was significantly higher than that in the mutants Δ betA (3.44 g/L) and Δ betB (2.68 g/L) under hyperosmotic stress and choline treatment. Moreover, choline enhanced the growth of SN15-2 greatly, but it did not enhance the growth of Δ betB under hyperosmotic stress. Choline combined with hyperosmotic adaptation significantly increased the lethal stress resistance of SN15-2 while the resistance of Δ betA and Δ betB was significantly decreased. This research illuminated a strategy underlying the adaptation to osmotic stress in P. protegens and provided an effective method to improve the stress resistance of this species, thus provided a theoretical basis for the practical application of P. protegens SN15-2.

Tài liệu tham khảo

Biryukova EN, Medentsev AG, Arinbasarova AY and Akimenko VK 2007 Adaptation of the yeast Yarrowia lipolyticato to heat shock. Microbiology 76 158–163

Chen C and Beattie GA 2007 Characterization of the osmoprotectant transporter OpuC from Pseudomonas syringae and demonstration that cystathionine-beta-synthase domains are required for its osmoregulatory function. J. Bacteriol. 189 6901–6912

Koga T and Takumi K 1995 Nutrient starvation induces cross protection against heat, osmotic, or H2O2 challenge in Vibrio parahaemolyticus. Microbiol. Immunol. 39 213–215

Rudulier DL, Strom AR, Dandekar A, Smith L and Valentine R 1984 Molecular biology of osmoregulation. Science 224 1064–1068