Features of Formation of Wheat's Increased Cold Resistance under the Influence of Gold Nanoparticles.

Increasing climatic instability, along with increasing technogenic pressure on the natural environment, necessitate the search for new approaches to increasing the resistance of wheat to abiotic factors, primarily to low temperature. A promising direction is the use of metal nanoparticles, which have the ability to positively influence plant metabolism in low concentrations. Due to their small size (less than 100 nm) and special physicochemical, optical, and electrical properties, nanoparticles penetrate cellular barriers, spread throughout the plant organism, affecting almost all processes in it. With wheat as an example (Triticum aestivum L., variety Zlata), it was shown for the first time that gold nanoparticles (GNPs) can act as adaptogens, increasing the cold resistance of plants. The study used priming—soaking of seeds in GNP solutions with concentrations 5–50 μg/mL for 24 h. The plants grown from seeds treated with GNPs differed from the control (untreated) ones in a number of physiological, biochemical, and molecular genetic parameters. Their growth processes and activity of the photosynthetic apparatus were significantly enhanced, and the expression of genes encoding large (rbcL) and small (rbcS) Rubisco subunits, as well as COR genes, Wcor726 and Wcor15, were increased. Moreover, wheat plants obtained from GNP-treated seeds differed from control ones in their increased resistance to low temperatures, and the effect was manifested both under control conditions and after low-temperature hardening. Concentration tests showed that the maximum effect was achieved when using GNPs at a concentration of 10 μg/mL. It is concluded that GNPs are able to influence plant metabolism and the expression of stress response genes, which leads to a significant increase in cold resistance. Possible mechanisms of GNP action on low temperature resistance are discussed. [ABSTRACT FROM AUTHOR]