Enhancement of germination and early seedling growth of rice (Oryza sativa) var. FARO44 by seed priming under normal and drought stressed conditions

Abstract

Rice is an important cereal consumed globally, however, poor germination and non-uniform seedling establishment are major causes of low rice yield in water-limiting arid ecosystems. Seed priming study with KNO3, SA and SiO2 to enhance germination and seedling growth was carried out with the objectives of (1) to determine the effects of seed priming on germination and early seedling growth, and (2) to evaluate effects of seed priming on physiological growth characteristics of rice seedling under drought stress simulated by polyethylene glycol (PEG6000). Under wellwatered conditions, rice seeds were primed with concentrations of KNO3 (2.5%, 5%, 10%, 15% and 20%), SiO2 (2.5%, 3%, 3.5%, 4% and 4.5%) and SA (0.5, 1, 1.5, 2, and 2.5 mM). While under drought stress, rice seeds were primed with 2.5% and 5% KNO3; 3% and 3.5% SiO2 and 1 mM and 2.5 mM SA. The results showed that all primed rice seedlings under both well-watered and drought stress conditions had significantly enhanced rice seedling growth parameters of seedling length, plumule length, root length, seedling vigor, seedling biomass and germination index and shorter germination time compared to unprimed controls. However, seed priming with concentrations of 2.5% and 5% KNO3; 3% and 3.5% SiO2, and 1 mM and 2.5 mM SA increased rice seedling growth parameters studied better than other concentrations. However, germination percentage was not significantly affected. Thus, priming of FARO44 rice with these concentrations of chemicals is recommended for fast germination, seedling growth and emergence in arid ecosystems.

A manipulative interplay between positive and negative regulators of phytohormones: A way forward for improving drought tolerance in plants

“…Several drought priming substances, such as plant growth regulators, are used to increase metabolic and enzymatic events in developing seed, which not only promote higher seed germination, but also enable plants to better withstand the DS. (Ali et al, 2020; Alamri et al, 2020; Kosar et al, 2020). In Arabidopsis , ABA‐mediated guard cell‐specific stomatal memory was able to maintain a partially closed stomatal aperture under DS (Virlouvet & Fromm, 2015).…”

A Beginner’s Guide to Osmoprotection by Biostimulants

“…However, as far as we know, increased production under stress was not reported using this silicon compound. SiO 2 is applied using micro- or nanoparticles to alleviate the deleterious effects of drought in rice [ 128 ] and salinity in potato. Indeed, it is possible to increase yield under drought stress using these nanoparticles [ 129 ].…”

“…In addition, published data show that humic and fulvic treatments can modify the plants’ primary and secondary metabolism against abiotic stress, enhancing water uptake and antioxidant behaviour under stress [ 193 ]. The application of both types of acids is widely reported in the literature as an external treatment to increase tolerance against osmotic stress (see Ali et al [ 128 , 194 ] for an extensive review): Humic acids are able to enhance maize plants’ salt response [ 195 ], increasing proline accumulation and strengthening the enzymatic antioxidant system. In Lima bean [ 196 ] it can ameliorate negative effects exerted by drought, by increasing photosynthetic activity and accumulating sugars and proline in leaves and thus a higher relative water content in these organs.…”

Biopriming of Maize Seeds with a Novel Bacterial Strain SH-6 to Enhance Drought Tolerance in South Korea

“…Seed biopriming is a promising approach to preventing the negative effects of water deficit on plant growth [8,23,24]. Indeed, plant resistance to abiotic stress can be improved significantly by seed biopriming, as it enhances gene expression related to the plant antioxidant system and plant metabolism to prevent oxidative and growth damage to achieve better yields [25].…”