Exogenous nitric oxide promotes salinity tolerance in plants: A meta-analysis

Abstract

Nitric oxide (NO) has received much attention since it can boost plant defense mechanisms, and plenty of studies have shown that exogenous NO improves salinity tolerance in plants. However, because of the wide range of experimental settings, it is difficult to assess the administration of optimal dosages, frequency, timing, and method of application and the overall favorable effects of NO on growth and yield improvements. Therefore, we conducted a meta-analysis to reveal the exact physiological and biochemical mechanisms and to understand the influence of plant-related or method-related factors on NO-mediated salt tolerance. Exogenous application of NO significantly influenced biomass accumulation, growth, and yield irrespective of salinity stress. According to this analysis, seed priming and foliar pre-treatment were the most effective methods of NO application to plants. Moreover, one-time and regular intervals of NO treatment were more beneficial for plant growth. The optimum concentration of NO ranges from 0.1 to 0.2 mM, and it alleviates salinity stress up to 150 mM NaCl. Furthermore, the beneficial effect of NO treatment was more pronounced as salinity stress was prolonged (>21 days). This meta-analysis showed that NO supplementation was significantly applicable at germination and seedling stages. Interestingly, exogenous NO treatment boosted plant growth most efficiently in dicots. This meta-analysis showed that exogenous NO alleviates salt-induced oxidative damage and improves plant growth and yield potential by regulating osmotic balance, mineral homeostasis, photosynthetic machinery, the metabolism of reactive oxygen species, and the antioxidant defense mechanism. Our analysis pointed out several research gaps, such as lipid metabolism regulation, reproductive stage performance, C4 plant responses, field-level yield impact, and economic profitability of farmers in response to exogenous NO, which need to be evaluated in the subsequent investigation.

Cell Mutagenic Autopolyploidy Enhances Salinity Stress Tolerance in Leguminous Crops

“…These antimitotic agents are widely reported and comparatively evaluated in literature for their efficiency in inducing chromosome doubling through in vitro and in vivo regeneration of varying plant species [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. As indicated in Figure 1 , the influence of these chemicals on the formation of more than one haploid genome in a single cell nucleus of plants occurs as a result of the interference with kinetochore-microtubule attachments or what is widely known as microtubule depolymerization which is also extensively reported [ 18 , 19 , 23 , 24 ].…”

Putting Biochar in Action: A Black Gold for Efficient Mitigation of Salinity Stress in Plants. Review and Future Directions

“…Salinity-induced osmotic stress causes water scarcity in plants and leads to a reduction in plant growth. Further, salinity also cause ionic toxicity and nutritional imbalance, therefore resulting in a significant reduction in plant growth. − Salinity stress negatively affects plant physiological processes including photosynthesis, nutrient acquisition, and water uptake. − Photosynthesis is one of the most important processes that provides energy and organic molecules for the growth and development of plants . However, plant photosynthesis is progressively reduced with increasing salinity stress owing to reduced carbon dioxide (CO 2 ) availability, disturbed light harvesting, hindered electron flow, and carbon assimilation .…”

Promotion of Ca2+ Accumulation in Roots by Exogenous Brassinosteroids as a Key Mechanism for Their Enhancement of Plant Salt Tolerance: A Meta-Analysis and Systematic Review

“…Wang et al [24] investigated the effects of melatonin on drought stress in plants by meta-analysis, which showed that the positive effects of melatonin on biomass and chlorophyll were diminished when the concentration range of melatonin was higher than 80-120 µmol L −1 and that the effects of soil application were more pronounced than those of foliar spraying. Tahjib et al [25] similarly used meta-analysis to conclude that the optimal concentration range for nitric oxide to alleviate salt stress (150 mM NaCl) in plants is 0.1-0.2 mM. Exogenous nitric oxide improves plant salt tolerance by alleviating oxidative damage, promoting photosynthesis, and improving ion homeostasis.…”