الفهرس 
ContentsOnly 14 pages are availabe for public view
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Abstract
Seeds of rice (Oryza sativa L), being a staple food for over half of the world’s population, are sensitive during germination and early growth stages to various abiotic stresses, including heavy metal stress, salinity, chilling and drought stress. Abiotic stress is the main factor negatively affecting crop growth and productivity worldwide. Accordingly, the present study was carried out to elucidate the effects of seed priming and plasma treatment on seed germination and seed vigor of two cultivars (Qian You No.1 (QY), Zhu Liang You 06 (ZY)) of rice under abiotic stress conditions through physiological, molecular and metabolomics approaches. It would be better to understand different mechanism of plant growth regulation to improve the germination and seedling growth under abiotic stress. Here different physiological and molecular analyses related with stress tolerance were performed which may provide a useful platform to improve stress-tolerant and increase rice seed vigor in response to different abiotic stresses. The main results were achieved as follows : 1. Seed priming with polyethylene glycol regulating the physiological, molecular and metabolic mechanism in rice under nano-ZnO stress. The ultrastructural analysis showed that leaf mesophyll and root cells were significantly damaged under nano-ZnO stress in both cultivars with a more prominent in ZY cultivar. However, seed priming with PEG significantly alleviate the toxic effects of nano-ZnO stress and improved the cell structures of leaf and roots in both cultivars. 2. Regulation of ZnO nanoparticles-induced physiological and molecular changes by seed priming with humic acid in Oryza sativa seedlings. Abscisic acid (ABA) content in germinating seeds under nano-ZnO stress was also higher than that under control conditions. Meanwhile, gibberellins (GA) content decreased under nano-ZnO stress. 3. Cold plasma treatment and exogenous salicylic acid priming enhances salinity tolerance of rice seedlings. 4. Seed priming with spermidine and 5-aminolevulinic acid improved seed polyamine metabolism under chilling stress in rice seedlings. 5. Priming with methyl jasmonate alleviated polyethylene glycol-initiated drought stress by regulating metabolic pathway in rice seed.