Plant Tolerance to Drought Stress in the Presence of Supporting Bacteria and Fungi: An Efficient Strategy in Horticulture

Abstract

Increasing temperature leads to intensive water evaporation, contributing to global warming and consequently leading to drought stress. These events are likely to trigger modifications in plant physiology and microbial functioning due to the altered availability of nutrients. Plants exposed to drought have developed different strategies to cope with stress by morphological, physiological, anatomical, and biochemical responses. First, visible changes influence plant biomass and consequently limit the yield of crops. The presented review was undertaken to discuss the impact of climate change with respect to drought stress and its impact on the performance of plants inoculated with plant growth-promoting microorganisms (PGPM). The main challenge for optimal performance of horticultural plants is the application of selected, beneficial microorganisms which actively support plants during drought stress. The most frequently described biochemical mechanisms for plant protection against drought by microorganisms are the production of phytohormones, antioxidants and xeroprotectants, and the induction of plant resistance. Rhizospheric or plant surface-colonizing (rhizoplane) and interior (endophytic) bacteria and fungi appear to be a suitable alternative for drought-stress management. Application of various biopreparations containing PGPM seems to provide hope for a relatively cheap, easy to apply and efficient way of alleviating drought stress in plants, with implications in productivity and food condition.

The Impact of Drought Stress on Soil Microbial Community, Enzyme Activities and Plants

“…Overall, the change of leaf area, which directly affects plant photosynthesis and yield, is one of the most easily observed features of plant leaves under drought stress [78]. Plants under drought stress have reduced the number of flowers and fresh and dry biomass [19]. Drought stress causes a decrease in nodulation [83] and nodule functioning [75].…”

“…The condition of the soil under drought stress strictly corresponds to plant growth and development. Drought directly affects plant morphology, physiology, and biochemistry [19]. It also reduces seed germination and seedling growth [20].…”

“…These adaptations can lead to the emergence of new functional groups in the ecosystem or serve as an important tool for improving agricultural practices and plant breeding programs [4,25]. Such drought-tolerant microorganisms and their traits could be used in the search for efficient compounds of biopreparations supporting plant growth [19].…”

Study of the Influence of Abiotic and Biotic Stress Factors on Horticultural Plants

“…Authors described the impact of stress caused by both climate change and human activity resulting in disorder of the optimum temperature (low-and high-temperature stresses), water balance (water and drought stress and irrigation) and the subsequent disturbance of soil parameters. The SI gathers eleven research papers [1][2][3][4][5][6][7][8][9][10][11] and one review [12]. Three papers were dedicated to cold stress, two to salt stress, two to inorganic pollutants such as metals and phosphate (Phi), three to climate change (i.e., high temperature, water and drought stress) and two to irrigation.…”

“…Among the classical parameters used as indicators of plant condition are morphological, anatomical, physiological, biochemical and genetical ones [12]. Physiological, biochemical and anatomical changes occurring in the plant under the influence of stress factors should be especially strongly noticed and analyzed.…”