Exogenously Supplemented Proline and Phenylalanine Improve Growth, Productivity, and Oil Composition of Salted Moringa by Up-Regulating Osmoprotectants and Stimulating Antioxidant Machinery

Abstract

Salinity is linked to poor plant growth and a reduction in global food output. Therefore, there is an essential need for plant adaptation and mitigation of salinity stress conditions. Plants combat salinity stress influences by promoting a set of physiological, biochemical, and molecular actions. Tremendous mechanisms are being applied to induce plant stress tolerance, involving amino acid application. For evaluating the growth and productivity of Moringa oleifera trees grown under salt stress conditions, moringa has been cultivated under different levels of salinity and subjected to a foliar spray of proline (Pro) and phenylalanine (Phe) amino acids. Moringa plants positively responded to the lowest level of salinity as the leaves, inflorescences, seeds, and oil yields have been increased, but the growth and productivity slightly declined with increasing salinity levels after that. However, Pro and Phe applications significantly ameliorate these effects, particularly, Pro-treatments which decelerated chlorophyll and protein degradation and enhanced vitamin C, polyphenols, and antioxidant activity. A slight reduction in mineral content was observed under the high levels of salinity. Higher osmoprotectants (proline, protein, and total soluble sugars) content was given following Pro treatment in salted and unsalted plants. A significant reduction in oil yield was obtained as affected by salinity stress. Additionally, salinity exhibited a reduction in oleic acid (C18:1), linoleic (C18:2), and linolenic (C18:3) acids, and an increase in stearic (C18:0), palmitic (C16:0), eicosenoic (C20:2), and behenic (C22:0) acids. Generally, Pro and Phe treatments overcome the harmful effects of salinity in moringa trees by stimulating the osmoprotectants, polyphenols, and antioxidant activity, causing higher dry matter accumulation and better defense against salinity stress.

Foliar Spray or Soil Drench: Microalgae Application Impacts on Soil Microbiology, Morpho-Physiological and Biochemical Responses, Oil and Fatty Acid Profiles of Chia Plants under Alkaline Stress

“…This may be attributable to the beneficial effects of microalgae as a biofertilizer [ 86 ], which also led to a rise in the activity of enzymes that help plants absorb nutrients, including nitrate reductase, dehydrogenase, alkaline or acidic phosphatase, and activity of ROS-scavenging enzymes such as catalase [ 87 ]. These parameters’ substantial increases could be explained by the fact that they are secondary metabolites [ 88 ]. Proteins, carbohydrates, and antioxidants as osmolytes and osmoprotectant compounds are essential for controlling osmotic pressure during alkaline stress conditions [ 89 , 90 ].…”

Changes in the Antioxidant Potential of Camellia sinensis Cultures under the Influence of Phenolic Precursors

“…On the example of Cicer arietinum leaves and Sequoia sempervirens callus culture, the increase in its content was shown in the presence of Phe, which was similar to our data [ 35 ]. While in the cells of the Moringa oleifera plant this trend was significantly less pronounced, herewith in quinoa sprouts there was no statistically significant difference between the experimental and control variants [ 30 , 46 ]. There are data confirming the increase in the accumulation of PCs in Carthamus tinctorius and Vigna radiata seedlings in the presence of Nar, while in the first case this indicator increased almost two-fold [ 27 , 28 ].…”

Essential oils prolonged the cut carnation longevity by limiting the xylem blockage and enhancing the physiological and biochemical levels

“…This in turn can be attributed to an increase in glucose synthesis and cellular activity [55]. Chlorophyll degradation is minimized when the glucose content is increased via osmotic pressure and respiration management [56][57][58]. Essential oils have antimicrobial property which prevents the growth of microbes that possess chlorophyllase activity, thereby preventing the degradation of chlorophyll [59,60].…”