不同储藏条件对优质稻胚细胞超微结构及抗氧化酶系统活性影响的研究

    EFFECTS OF STORAGE CONDITIONS ON THE ULTRA-STRUCTURE AND ANTIOXIDANT ENZYME ACTIVITY OF RICE GERMPLASM WITH HIGHQUALITY

    • 摘要: 以两优系列优质稻为材料,探索在常规水分含量(13.5%、14.5%)和温度(15、20、30℃)条件下储藏的稻谷细胞内各项理化指标及其抗氧化防御系统中抗氧化酶和抗氧化剂的变化,观察稻谷胚细胞结构,探究储藏条件对稻谷细胞衰老损伤的影响。结果表明:随着储藏时间的延长和储藏环境温度的增高,超氧阴离子自由基、脂肪酸值和丙二醛呈逐渐上升的趋势,可溶性蛋白呈逐渐下降的趋势。超氧阴离子自由基、脂肪酸等有害物质的积累,破坏了稻谷细胞的代谢平衡,生物酶合成能力降低,超氧化歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)等抗氧化酶的量大大减少,抗氧化酶系统被破坏,细胞衰老加速。储藏后期,高温条件下的稻谷胚细胞形态变形较严重,细胞壁出现溶解,细胞膜内陷并出现了破损,原生质体内缩严重,核膜溶解破损,核仁变形出现分裂,细胞核异染色质凝聚加深,异染色质充满整个细胞核,稻谷胚细胞超微结构破损严重;低温条件下的稻谷胚细胞细胞壁结构无明显褶皱,细胞核膜清晰,细胞核仁形态正常,染色质凝聚,颜色稍有加深,胚细胞结构较完整。低温低水分储藏条件有利于优质稻的品质保鲜。

       

      Abstract: The present study was to investigate the changes of physico-chemical indexes and antioxidant enzymes and antioxidants in the antioxidant defense system of rice cells stored under the conditions of conventional moisture content (13.5%,14.5%) and temperature (15℃,20℃ and 30℃) using'liangyou series'high-quality rice as raw material.The cell structure of rice embryo was observed to investigate the effect of storage conditions on the aging of rice cells.The results showed that with the increase of ambient temperature and prolongation of storage time,superoxide anion radicals,fatty acid and malondialdehyde showed a gradual increase trend,while soluble protein showed an opposite trend.The accumulation of harmful substances such as fatty acids and superoxide anion radical destroyed the metabolic balance of cells of rice.Meanwhile,the ability of enzyme synthesis was weakened,the amount of antioxidant enzymes,including superoxide dismutase (SOD),catalase (CAT) and peroxidase (POD) was reduced greatly,the antioxidant enzyme system was destroyed,and the aging of cells was accelerated.At the late stage of storage,the rice embryo cells were seriously deformed under high temperature,cell wall appeared to dissolve,cell membrane was collapsed and damaged,protoplast shrank seriously,nuclear membrane was dissolved and damaged,nucleolus was deformed and split,the nucleus hetero-chromatin condensation was deepened,heterochromatin was filled the entire nucleus,and the ultra-structure of rice germ cell was seriously damaged.On the contrary,under the storage condition of lower temperature,the cell wall structure of rice embryo cells had no wrinkles,nuclear membrane was clear,nucleolus had normal morphology,chromatin condensation was slightly deepened,and the structure of embryonic cell was integrated,indicating that the storage conditions of low temperature and low moisture was beneficial to the quality preservation of rice with high quality.

       

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