TY  - EJOU
AU  - Tahjib-Ul-Arif, Md. 
AU  - Asaduzzaman, Md 
AU  - Shirazy, Bir Jahangir 
AU  - Khan, Md. Shihab Uddine 
AU  - Rahman, A. M. Sajedur 
AU  - Murata, Yoshiyuki 
AU  - Hamed, Sozan Abdel 
AU  - Latef, Arafat Abdel Hamed Abdel 

TI  - Seed Priming Improves Chilling Stress Tolerance in Rice (<i>Oryza sativa</i> L.) Seedlings
T2  - Phyton-International Journal of Experimental Botany

PY  - 2024
VL  - 93
IS  - 11
SN  - 1851-5657

AB  - Chilling is one of the major abiotic stresses for plants, especially for rice cultivation. Many essential metabolic processes for growth and development are temperature-dependent. In that case, reducing the negative effects of cold stress using exogenous chemicals is a possible option. Therefore, the current study examined the effects of pre-sowing seed treatment with different chemicals, <i>viz</i>. hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), salicylic acid (SA), calcium chloride (CaCl<sub>2</sub>), thiourea (TU), and citric acid (CA) on the germination of rice seeds (cv. BRRI dhan28) under chilling environments. Rice seeds were soaked in distilled water (control), 10 mM CA, 2 mM SA, 10 mM CaCl<sub>2</sub>, 10 mM H<sub>2</sub>O<sub>2</sub>, and 10 mM TU solutions for 24 h. After that, seeds were exposed to chilling stress by incubating at 4 ± 1°C for 8 h, followed by at 25 ± 2°C for 16 h for 7 days. Exposure to chilling stress significantly reduced the final germination percent (13.6%), germination rate index (36.0%), coefficient of the velocity (25.0%), shoot fresh weight (44.4%), and root fresh weight (60.5%). Moreover, chilling induced oxidative damage and reduced the activity of antioxidant enzymes (catalase and ascorbate peroxidase). In contrast, treatments with H<sub>2</sub>O<sub>2</sub>, SA, CaCl<sub>2</sub>, TU, and CA considerably enhanced germination indices and seedling growth compared to chilling stress conditions. The study showed that priming with H<sub>2</sub>O<sub>2</sub>, SA, CaCl<sub>2</sub>, TU, and CA significantly boosted antioxidant enzyme activities and reduced MDA and H<sub>2</sub>O<sub>2</sub> contents in chilling-stressed rice plants, indicating less oxidative stress and improved tolerance. Principal component analysis showed that among these priming agents, H<sub>2</sub>O<sub>2</sub>, SA, and CA are most effective in chilling stress mitigation. Therefore, using seed-treating chemicals to combat the effect of chilling stress can help rice seedlings grow better in the winter season.
KW  - Chilling stress; antioxidant enzymes; germination indices; cold injury; seed priming; oxidative stress

DO  - 10.32604/phyton.2024.058710