The Role of Plant Growth-Promoting Bacteria in Alleviating the Adverse Effects of Drought on Plants

Abstract

Plant growth-promoting bacteria play an essential role in enhancing the physical, chemical and biological characters of soils by facilitating nutrient uptake and water flow, especially under abiotic stress conditions, which are major constrains to agricultural development and production. Drought is one of the most harmful abiotic stress and perhaps the most severe problem facing agricultural sustainability, leading to a severe shortage in crop productivity. Drought affects plant growth by causing hormonal and membrane stability perturbations, nutrient imbalance and physiological disorders. Furthermore, drought causes a remarkable decrease in leaf numbers, relative water content, sugar yield, root yield, chlorophyll a and b and ascorbic acid concentrations. However, the concentrations of total phenolic compounds, electrolyte leakage, lipid peroxidation, amounts of proline, and reactive oxygen species are considerably increased because of drought stress. This negative impact of drought can be eliminated by using plant growth-promoting bacteria (PGPB). Under drought conditions, application of PGPB can improve plant growth by adjusting hormonal balance, maintaining nutrient status and producing plant growth regulators. This role of PGPB positively affects physiological and biochemical characteristics, resulting in increased leaf numbers, sugar yield, relative water content, amounts of photosynthetic pigments and ascorbic acid. Conversely, lipid peroxidation, electrolyte leakage and amounts of proline, total phenolic compounds and reactive oxygen species are decreased under drought in the presence of PGPB. The current review gives an overview on the impact of drought on plants and the pivotal role of PGPB in mitigating the negative effects of drought by enhancing antioxidant defense systems and increasing plant growth and yield to improve sustainable agriculture.

Seed Priming Boost Adaptation in Pea Plants under Drought Stress

“…Pisum sativum L. is one of the most essential vegetable winter crops cultivated in Egypt, and most cultivars are grown for fresh and dry seeds because it contains a high amount of protein, vitamins, carbohydrates, and minerals like iron, phosphorus, and zinc [ 1 ]. Increasing the growth and yield of pea plants and other economic plants is considered an important target; there are many environmental factors that affect and harm the growth stages of many plants, such as salinity on strawberry, sweet pepper, rice, cucumber, and faba bean [ 2 , 3 , 4 , 5 , 6 , 7 ], and drought stress on faba bean, barley, sugar beet, maize and wheat plants [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Anticryptosporidium Efficacy of Olea europaea and Ficus carica Leaves Extract in Immunocompromised Mice Associated with Biochemical Characters and Antioxidative System

“…Glutathione (GSH) plays an important role in counteracting oxidative damage and cell death [ 10 , 11 ]. These antioxidant enzymes play an important role in scavenging reactive oxygen species such as super oxide and hydrogen peroxide and protect the cell against oxidative stress and, finally, cell death [ 12 , 13 , 14 , 15 , 16 ].…”

“…Gastrointestinal inflammation occurring via the intestinal parasites is frequently accompanied by functional disturbances, marked modifications in the structure and chemical content of the gut. The body's antioxidant defenses include of 12 scavenging enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH) and catalase (CAT) [3]. CAT activity is adversely affected by oxidative stress caused by various diseases such as toxoplasmosis [4].…”

The Contrivance of Plant Growth Promoting Microbes to Mitigate Climate Change Impact in Agriculture

“…Proline is a particularly important osmoprotectant for plants under drought conditions. The increase in its concentration is a marker of abiotic stress caused by water scarcity [ 105 , 106 , 107 ]. Proline accumulation in the cell allows reduction of the osmotic stress caused by the reduced amount of water.…”

“…Proline reduces water potential and protects cells from the toxic effects of accumulated ions. Plant mutants that cannot produce proline are significantly less drought tolerant [ 106 , 107 ].…”