Tomato (Solanum lycopersicum L.) is an important vegetable cultivated around the world. Under field conditions, tomato can be negatively affected by water scarcity in arid and semiarid regions. The application of native plant growth-promoting rhizobacteria (PGPR) isolated from arid environments has been proposed as an inoculant to mitigate abiotic stresses in plants. In this study, we evaluated rhizobacteria from Cistanthe longiscapa (syn Calandrinia litoralis and Calandrinia longiscapa), a representative native plant of flowering desert (FD) events (Atacama Desert, Chile), to determine their ability to reduce water scarcity stress on tomato seedlings. The isolated bacterial strains were characterized with respect to their PGPR traits, including P solubilization, 1-aminocyclopropane-1-carboxylate deaminase activity, and tryptophan-induced auxin and exopolysaccharide production. Three PGPR consortia were formulated with isolated Bacillus strains and then applied to tomato seeds, and then, the seedlings were exposed to different levels of water limitations. In general, tomato seeds and seedlings inoculated with the PGPR consortia presented significantly (P ≤ 0.05) greater plant growth (48 to 60 cm of height and 171 to 214 g of weight) and recovery rates (88 to 100%) compared with those without inoculation (37 to 51 cm of height; 146 to 197 g of fresh weight; 54 to 92% of recovery) after exposure to a lack of irrigation over different time intervals (24, 72 and 120 h) before transplantation. Our results revealed the effectiveness of the formulated PGPR consortia from FD to improve the performance of inoculated seeds and seedlings subjected to water scarcity; thus, the use of these consortia can represent an alternative approach for farmers facing drought events and water scarcity associated with climate change in semiarid and arid regions worldwide.
Bibliographical noteFunding Information:
This study was funded by the National Fund for Scientific and Technological Development (FONDECYT) Projects No. 1160302, 1181050 and 1201386 (to M.A.J. and J.J.A.), by the ANID (ex-CONICYT) Ph.D. Scholarship no. 21151002 (to M.A.E.) and 21160935 (S.G.), by the “Apoyo a Profesores Patrocinantes de Alumnos de Pre y Postgrado” program, code DI19-2016, Vicerrectoría de Investigación y Postgrado, Universidad de La Frontera (to M.A.E. and S.G.), and by funding from the Minnesota Agricultural Experiment Station (to M.J.S). The authors would like to thank Geographer Rodrigo Arcos Mg for providing logistic support during the flowering desert sampling campaign. Finally, all authors would also like to thank the two anonymous reviewers for their suggestions and comments.
© 2021, The Author(s).
PubMed: MeSH publication types
- Journal Article