Plant growth promoting rhizobacteria alleviates drought stress in potato in response to suppressive oxidative stress and antioxidant enzymes activities

Abstract

Maintenance of plant physiological functions under drought stress is normally considered a positive feature as it indicates sustained plant health and growth. This study was conducted to investigate whether plant growth-promoting rhizobacteria (PGPR) Bacillus subtilis HAS31 has potential to maintain potato growth and yield under drought stress. We analyzed trends of chlorophyll concentration, photosynthesis process, relative water content, osmolytes, antioxidants enzymes and oxidative stress, relative growth rate, tuber and aboveground biomass production in two potato varieties, Santae (drought-tolerant) and PRI-Red (drought-sensitive). Plants of both genotypes were treated with 100 g of HAS31 inoculant at 10 days after germination and exposed to different soil relative water contents (SRWC), including 80 ± 5% (well watered), 60 ± 5% (moderate stress) and 40 ± 5% SRWC (severe stress) for 7 days at tuber initiation stage (30 days after germination). The drought stress reduced plant relative growth rate, biomass production, leaf area, number of leaves and tubers, tuber weight, and final yield. The drought-stressed plants showed decline in chlorophyll contents, membrane stability, leaf relative water contents and photosynthetic rate. Under drought stress, enzymatic activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), contents of total soluble sugars, soluble proteins and proline increased. The application of PGPR reduced the impact of drought and maintained higher growth and physio-chemical traits of the plants. The plants with PGPR application showed higher relative growth rate, dry matter production, leaf area, number of tubers, tuber weight and yield as compared to plants without PGPR. The PGPR-HAS31 treated plants maintained higher photosynthetic process, contents of chlorophyll, soluble proteins, total soluble sugars, and enzymatic activities of CAT, POD and SOD as compared to plants without PGPR. The results of the study suggest that plant growth regulators have ability to sustain growth and yield of potato under drought stress by maintaining physiological functions of the plants.

Rhizospheric Bacillus amyloliquefaciens Protects Capsicum annuum cv. Geumsugangsan From Multiple Abiotic Stresses via Multifarious Plant Growth-Promoting Attributes

“…With environmental stresses, plants produce reactive oxygen species (ROS), which at high levels can cause oxidative damage, impair membrane lipid functions, inactivate enzymes, and impede metabolic activities ( Huang et al, 2019 ). In the present study, we observed that H 2 O 2 and MDA levels were clearly higher in stressed plants, which agrees with a previous report ( Batool et al, 2020 ). PGPR application, however, obviously mitigated the high H 2 O 2 and MDA levels in stressed plants by the end of the experiment.…”

“…PGPR application, however, obviously mitigated the high H 2 O 2 and MDA levels in stressed plants by the end of the experiment. Therefore, PGPR might suppress the production of ROS and thereby prevent oxidative-based cell membrane damage under environmental stress ( Han and Lee, 2005 ; Singh et al, 2015 ; Banik et al, 2016 ; Batool et al, 2020 ).…”

Amelioration of short‐term drought stress during different growth stages in Brassica juncea by rhizobacteria mediated maintenance of ROS homeostasis

“…However, rhizobacterial inoculation led to significant improvement in RWC during the vegetative stage, which is in congruence with previous reports (Naveed et al, 2014;Tiwari et al, 2016 (Batool et al, 2020). Bandeppa et al (2019) also observed significant improvement in RWC and MSI due to inoculation in mustard under drought stress condition.…”

Physiological, Biochemical and Yield-Component Responses of Solanum tuberosum L. Group Phureja Genotypes to a Water Deficit

“…The increased contents of soluble sugars under water deficit conditions ( Table 1 ) indicated that the plant used an osmoregulatory response to prevent cell dehydration as the water deficit advanced, maintaining metabolic functions and evading dehydration [ 44 , 45 , 46 ]. A similar trend has been reported in tetraploid potatoes [ 47 ], rice [ 17 ] and wheat [ 48 , 49 ]. Nevertheless, an accumulation of soluble sugar contents and low RWC values were observed under the water deficit, indicating that the accumulation of soluble sugars is not enough to maintain stable water relations ( Table 1 ).…”