Impacts of plant growth promoters and plant growth regulators on rainfed agriculture

• Published in: PloS one Vol. 15; no. 4; p. e0231426
• Main Authors: Khan, Naeem, Bano, Asghari M D, Babar, Ali
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09-04-2020; Public Library of Science (PLoS)
• Subjects: Abiotic stress; Acetic acid; Acids; Agricultural chemicals; Agricultural industry; Agricultural land; Agricultural production; Agriculture; Ammonia; Antibacterial agents; Antifungal activity; Antifungal agents; Antioxidants; Antioxidants (Nutrients); Auxins; Biochemistry; Biology and Life Sciences; Chickpeas; Chlorophyll; Crop damage; Crop growth; Crops; Cultivation; Cyanides; Drought; Drought resistance; Droughts; Ecology and Environmental Sciences; Enzymes; Fungicides; Gene sequencing; Genes; Growth; Growth regulators; Hydrogen; Hydrogen cyanide; Indoleacetic acid; Inoculation; Legumes; Lipid peroxidation; Lipids; Medicine and Health Sciences; Metabolites; Moisture stress; Nitriles; Nodules; Organic acids; Oxidases; Peroxidation; Phenols (Class of compounds); Physical Sciences; Physiological aspects; Physiological effects; Physiology; Plant growth; Plant growth promoters; Plant hormones; Plant production; Plant tolerance; Planting; Polyamines; Population growth; Precipitation; Production management; Proline; Putrescine; Rainfed farming; Research and Analysis Methods; RNA; rRNA 16S; Salicylic acid; Sandy soils; Seedlings; Seeds; Soil microbiology; Soil microorganisms; Soil moisture; Soils; Weight; Florida; United States > US; Pakistan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0231426

Demand for agricultural crop continues to escalate in response to increasing population and damage of prime cropland for cultivation. Research interest is diverted to utilize soils with marginal plant production. Moisture stress has negative impact on crop growth and productivity. The plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGR) are vital for plant developmental process under moisture stress. The current study was carried out to investigate the effect of PGPR and PGRs (Salicylic acid and Putrescine) on the physiological activities of chickpea grown in sandy soil. The bacterial isolates were characterized based on biochemical characters including Gram-staining, P-solubilisation, antibacterial and antifungal activities and catalases and oxidases activities and were also screened for the production of indole-3-acetic acid (IAA), hydrogen cyanide (HCN) and ammonia (NH3). The bacterial strains were identified as Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium based on the results of 16S-rRNA gene sequencing. Chickpea seeds of two varieties (Punjab Noor-2009 and 93127) differing in sensitivity to drought were soaked for 3 h before sowing in fresh grown cultures of isolates. Both the PGRs were applied (150 mg/L), as foliar spray on 20 days old seedlings of chickpea. Moisture stress significantly reduced the physiological parameters but the inoculation of PGPR and PGR treatment effectively ameliorated the adverse effects of moisture stress. The result showed that chickpea plants treated with PGPR and PGR significantly enhanced the chlorophyll, protein and sugar contents. Shoot and root fresh (81%) and dry weights (77%) were also enhanced significantly in the treated plants. Leaf proline content, lipid peroxidation and antioxidant enzymes (CAT, APOX, POD and SOD) were increased in reaction to drought stress but decreased due to PGPR. The plant height (61%), grain weight (41%), number of nodules (78%) and pod (88%), plant yield (76%), pod weight (53%) and total biomass (54%) were higher in PGPR and PGR treated chickpea plants grown in sandy soil. It is concluded from the present study that the integrative use of PGPR and PGRs is a promising method and eco-friendly strategy for increasing drought tolerance in crop plants.