Prospective Practice for Compound Stress Tolerance in Thyme Plants Using Nanoparticles and Biochar for Photosynthesis and Biochemical Ingredient Stability

Abstract

Global climatic change leads to many detrimental effects on all life forms. Outstanding case, salinity, and drought are considered multidimensional stress that severely affect plant growth and sustainable agriculture. Thymus vulgaris is a medicinal plant that has phytochemical constituents, and it is threatened by several abiotic stresses caused by climate change. Therefore, the present study aims to evaluate the physiological response and thyme tolerance grown on a newlyreclaimed saline sandy soil under drought conditions and treated by biochar-loaded biofertilizers, nano-zeolite, and nano-silicon through two consecutive seasons. The nanoparticles enhanced plant growth and alleviated the adverse effect of drought. Additionally, a synergistic effect was noticed when combining nanoparticles and biofertilizers. The quadruple combined treatment of nano-zeolite, nano-silicon, biochar, and organic matter (T7) significantly increased thyme morphological traits, photosynthetic parameters, oil, and yield compared to control treatment. Additionally, T7 increased the concentration of endogenous nutrients (N, P, K, Na, Ca, Mg, Zn, Fe, Mn), proline, total phenols, and total flavonoids, in addition to indoleacetic acid, gibberellic acid, and antioxidant enzymes in thyme compared to other treatments. T7 showed the lowest concentration of soluble sugars, abscisic acid, and transpiration rate. Interestingly, T7 increased the medicinal benefits of thyme by increasing its vital hydrocarbons, and oxygenated compounds. These findings introduce a dual benefit of nano-fertilizers in combination with biochar and organic matter in ameliorating soil salinity and drought along with increasing thymegrowth, productivity, and therapeutic value.

Foliar Application of Different Iron Sources Improves Morpho-Physiological Traits and Nutritional Quality of Broad Bean Grown in Sandy Soil

“…In corn ( Zea mays L.), FeNPs (particle size 17.7 nm) at 20 mg/L under hydroponic conditions significantly increased root elongation [ 47 ]. Generally, the increase in the accumulation of Fe element in the leaves of treated broad bean plants with nano-iron fertilizers than other applied fertilizers may be linked to the properties of Fe nanoparticles which are characterized by a smaller surface area, higher absorption, and more ease of attachment than other forms of iron [ 56 , 57 ].…”

The critical role of biochar to mitigate the adverse impacts of drought and salinity stress in plants

“…Moreover, DS also causes stomata to close which decreases the conductance of stomata to the loss of water and negatively affects photosynthesis and transpiration rates ( Mahmoud and Swaefy, 2020 ). Additionally, DS causes the destruction of enzymes and proteins along with a reduction in the synthesis of chlorophyll, which in turn causes a marked reduction in photosynthesis and, subsequently, plant productivity ( Mahmoud et al., 2022a ; Mahmoud et al., 2022b ).…”