Nanopriming technology for enhancing germination and starch metabolism of aged rice seeds using phytosynthesized silver nanoparticles

Abstract

Application of nanomaterials for agriculture is relatively new as compared to their use in biomedical and industrial sectors. In order to promote sustainable nanoagriculture, biocompatible silver nanoparticles (AgNPs) have been synthesized through green route using kaffir lime leaf extract for use as nanopriming agent for enhancing seed germination of rice aged seeds. Results of various characterization techniques showed the successful formation of AgNPs which were capped with phytochemicals present in the plant extract. Rice aged seeds primed with phytosynthesized AgNPs at 5 and 10 ppm significantly improved germination performance and seedling vigor compared to unprimed control, AgNO3 priming, and conventional hydropriming. Nanopriming could enhance α-amylase activity, resulting in higher soluble sugar content for supporting seedlings growth. Furthermore, nanopriming stimulated the up-regulation of aquaporin genes in germinating seeds. Meanwhile, more ROS production was observed in germinating seeds of nanopriming treatment compared to unprimed control and other priming treatments, suggesting that both ROS and aquaporins play important roles in enhancing seed germination. Different mechanisms underlying nanopriming-induced seed germination were proposed, including creation of nanopores for enhanced water uptake, rebooting ROS/antioxidant systems in seeds, generation of hydroxyl radicals for cell wall loosening, and nanocatalyst for fastening starch hydrolysis.

Nanoparticle-Mediated Seed Priming Improves Germination, Growth, Yield, and Quality of Watermelons (Citrullus lanatus) at multi-locations in Texas

“…In comparative phytotoxicity studies, our group has demonstrated the negative impacts of bulk Fe particles as compared to the Fe nanoparticles on chlorophyll synthesis of watermelon seedlings 11 . Our results are in agreement with similar studies by other groups, which have demonstrated the inhibitory effect of bulk silver particles as compared to silver nanoparticles 26,35,36 . These studies confirmed the phytotoxic effects of silver are not due to nanoparticles but owing to the Ag + ions.…”

“…Significant differences in yield were also observed in AgNP-treated watermelon of both cultivars at Snook, as well as non-significant increases in Grapeland and Weslaco. The results are in agreement with studies on onion 41 , Brassica juncea 33 , common beans, corn 42 , safflower cultivars 43 , rice 26 , and wheat 44 . AgNPs increased plant growth and biochemical attributes of Brassica juncea 33 , and seed yield of safflower cultivars 43 .…”

“…The germination results agree with previous studies of watermelon, zucchini, and corn crops 24 , which showed that, that compared with untreated watermelon, the germination rate was enhanced at all the AgNP concentrations (0.05 to 2.5 mg/mL) 24 . Similarly, enhanced germination was observed using AgNPs in rice 25,26 and Boswellia ovalifoliolata 27 .…”

“…These studies confirmed the phytotoxic effects of silver are not due to nanoparticles but owing to the Ag + ions. Indeed, Ag accumulation in seeds primed with AgNPs was lower than those of AgNO 3 and this higher Ag accumulation inhibits seed germination and seedling growth in rice 26 , onion 37 , castor 35 , maize 38 www.nature.com/scientificreports www.nature.com/scientificreports/ nanopriming enhanced growth and yield while maintaining nutritional quality. AgNP-treated watermelon vines had longer and thicker vines as compared to the control and TNE-treated watermelons.…”

Carbon Nanoparticles Functionalized with Carboxylic Acid Improved the Germination and Seedling Vigor in Upland Boreal Forest Species

“…Different priming techniques have been applied in agriculture crops to alleviate seed dormancy, improve germination rates, enhance seedling vigor and seedling capacity to grow and establish across a range of sites with varying environmental conditions [13][14][15][16][17][18][19]. Such priming techniques include hydrating seeds in salt solutions (halopriming), solutions of beneficial microbes (biopriming), osmotic solution (osmopriming), plant hormones solutions (hormonal priming), presence of a magnetic field (magneto-priming), solutions mixed with a solid carrier (matriconditioning), solutions of nanoparticles (nanopriming) or hydrating seeds in water (hydropriming) [15,20,21]. The realization of the potential use of nanotechnology in many sectors, including agriculture, has increased recently [18,22,23].…”