A Combined Use of Rhizobacteria and Moringa Leaf Extract Mitigates the Adverse Effects of Drought Stress in Wheat (Triticum aestivum L.)

Abstract

Less nutrient availability and drought stress are some serious concerns of agriculture. Both biotic and abiotic stress factors have the potential to limit crop productivity. However, several organic extracts obtained from moringa leaves may induce immunity in plants under nutritional and drought stress for increasing their survival. Additionally, some rhizobacterial strains have the ability to enhance root growth for better nutrient and water uptake in stress conditions. To cover the knowledge gap on the interactive effects of beneficial rhizobacteria and moringa leaf extracts (MLEs), this study was conducted. The aim of this experimental study was to investigate the effectiveness of sole and combined use of rhizobacteria and MLEs against nutritional and drought stress in wheat. Nitrogen-fixing bacteria Pseudomonas aeruginosa (Pa) (108 CFU ml–1) was inoculated to wheat plants with and without foliar-applied MLEs at two different concentrations (MLE 1 = 1:15 v/v and MLE 2 = 1:30 v/v) twice at 25 and 35 days after seed sowing (50 ml per plant) after the establishment of drought stress. Results revealed that Pa + MLE 2 significantly increased fresh weight (FW), dry weight (DW), lengths of roots and shoot and photosynthetic contents of wheat. A significant enhancement in total soluble sugars, total soluble proteins, calcium, potassium, phosphate, and nitrate contents validated the efficacious effect of Pa + MLE 2 over control-treated plants. Significant decrease in sodium, proline, glycine betaine, electrolyte leakage, malondialdehyde, hydrogen peroxide, superoxide dismutase (SOD), and peroxide (POD) concentrations in wheat cultivated under drought stress conditions also represents the imperative role of Pa + MLE 2 over control. In conclusion, Pa + MLE 2 can alleviate nutritional stress and drought effects in wheat. More research in this field is required to proclaim Pa + MLE 2 as the most effective amendment against drought stress in distinct agroecological zones, different soil types, and contrasting wheat cultivars worldwide.

Probiotics, Proline and Calcium Induced Protective Responses of Triticum aestivum under Drought Stress

“…Abdelaal and colleagues [ 20 ] showed similar results with proline on barley. These results are in agreement with those obtained by Lalarukh et al [ 9 ], who showed that winter wheat inoculated with Pseudomonas aeruginosa and Azeem et al [ 37 ], who showed that maize plants treated with Bacillus strains reduced the formation of H 2 O 2 under drought stress in comparison to uninoculated control plants. Our results showed that the addition of Ca to the soil has a positive effect on protecting winter wheat cells from oxidative damage.…”

“…We found data about the positive effect of exogenous calcium [ 30 , 35 ] and plant microbial probiotics application on the chlorophyll content of wheat seedlings exposed to drought. It was reported that Burkholderia phytofirmans , Bacillus megaterium and Bacillus licheniformis , Pseudomonas aeruginosa significantly improve chlorophyll content under drought stress conditions [ 9 , 36 , 37 ]. Our study showed that the application of microbial probiotic preparation ProbioHumus and Ca increased the total content of chlorophyll under drought conditions.…”

“…For example, some researchers used compounds such as plant growth regulators, amino acids, calcium ions, and other chemicals for the recovery of plant growth under drought stress [ 5 , 6 , 7 ]. Currently, we find data that plant probiotics can significantly improve the growth and yield of winter wheat grown under drought conditions [ 8 , 9 , 10 ]. They can considerably reduce the effect of drought on winter wheat by enhancing the physiological aspects of the plant: RWC, membrane stability, chlorophyll content, water potential, proline, and sugar [ 5 ].…”

Integral effects of brassinosteroids and timber waste biochar enhances the drought tolerance capacity of wheat plant

“…Moreover, this nutrient is highly mobile in plant and acts directly in regulating the osmotic potential in compartments to increase their turgor 46 . Generally, the nutrient imbalance that occurred in drought-stressed plants may led to undesirable drop in plant pigments (chlorophyll A, chloro B, total chlorophyll and carotenoids) and photo-assimilates 16 , 47 .…”

“…Biochar is another promising additive that can mitigate the adverse effects of drought on plant growth and productivity, e.g., sorghum 14 , maize 15 and wheat 2 , 16 . This might take place via (I) increasing soil water retention, hence reducing soil irrigation demands 17 , (II) increasing nutrient use efficiency 18 , (III) stimulating auxin, gibberellin and brassinosteroids regulation 19 and (IV) increasing plant chlorophyll content 20 , stomatal conductance, cytotoxicity and leaf K + content 21 .…”