Biostimulants for the Regulation of Reactive Oxygen Species Metabolism in Plants under Abiotic Stress

Abstract

Global food security for a growing population with finite resources is often challenged by multiple, simultaneously occurring on-farm abiotic stresses (i.e., drought, salinity, low and high temperature, waterlogging, metal toxicity, etc.) due to climatic uncertainties and variability. Breeding for multiple stress tolerance is a long-term solution, though developing multiple-stress-tolerant crop varieties is still a challenge. Generation of reactive oxygen species in plant cells is a common response under diverse multiple abiotic stresses which play dual role of signaling molecules or damaging agents depending on concentration. Thus, a delicate balance of reactive oxygen species generation under stress may improve crop health, which depends on the natural antioxidant defense system of the plants. Biostimulants represent a promising type of environment-friendly formulation based on natural products that are frequently used exogenously to enhance abiotic stress tolerance. In this review, we illustrate the potential of diverse biostimulants on the activity of the antioxidant defense system of major crop plants under stress conditions and their other roles in the management of abiotic stresses. Biostimulants have the potential to overcome oxidative stress, though their wider applicability is tightly regulated by dose, crop growth stage, variety and type of biostimulants. However, these limitations can be overcome with the understanding of biostimulants’ interaction with ROS signaling and the antioxidant defense system of the plants.

Collaborative Impact of Compost and Beneficial Rhizobacteria on Soil Properties, Physiological Attributes, and Productivity of Wheat Subjected to Deficit Irrigation in Salt Affected Soil

“…However, it was noted that SOD, CAT, and POX activities are further increased under the coupled application of compost and PGPR perhaps owing to reduced Na uptake [ 65 ]. In harmony with our findings, prior investigations presented augmented SOD, CAT, and POX under abiotic stress [ 66 ]. These enzymes convert H 2 O 2 into non-toxic compounds such as H 2 O and O 2 and thus protect the plants from their harmful impacts on cell membranes and macromolecules [ 67 ].…”

Effect of Pyroligneous Acid on the Productivity and Nutritional Quality of Greenhouse Tomato

“…A reduction in stomatal conductance is an adaptive strategy used by plants to minimize water loss during water-deficit and other related climatic stress conditions. This scenario adversely affects CO 2 diffusion and net photosynthesis [37]. Although the photosynthesis rate in the present study was not affected by PA treatment, we surmised that the reduction in stomatal conductance with PA treatment could be due to adaptive thermoregulation of the photosynthesis system and stress mitigation mechanism [35], which will require further investigation.…”

Quinoa Response to Application of Phosphogypsum and Plant Growth-Promoting Rhizobacteria under Water Stress Associated with Salt-Affected Soil

“…In addition, soil salinity and water stress can prompt severe damage to the ovary, and consequently may result in a decline in productivity [ 52 ]. However, the combined application of phosphogypsum and PGPR were more efficient to improve quinoa yield components and quality such as plant height (cm), 1000-grain weight (gm), grain yield, foliage yields, biological yield, and harvest index as well as qualities such as grain protein content and saponin content, as a consequence of alleviating the injurious effect of water stress and soil salinity compared to untreated plants (control treatment), which can enhance seed sterility [ 53 ]. The high efficiency of phosphogypsum could be due to its ability to lessen osmotic damage, decline Na + uptake, augment K + uptake, thereby keeping healthy flag leaf, increase photosynthesis with high net assimilation rate, translocate from sources to sink alongside starch accumulation in the chloroplast, decline oxidative damage, delay senescence, improve water uptake, and augment the antioxidative capacity [ 54 ].…”