Physiological effects of glycinebetaine on gamma-irradiated stressed fenugreek plants
Physiological effects of glycinebetaine on gamma-irradiated stressed fenugreek plants
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DOI：
10.1007/s11738-010-0641-4
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发表时间：
2011-07-01
影响因子：
2.6
通讯作者：
Jaleel, C. Abdul
中科院分区：
文献类型：
--
作者：
Moussa, H. R.;Jaleel, C. Abdul
辐射胁迫对植物的生长发育有不利影响。甜菜碱在植物中的辐射防护作用尚未见报道，其机制也不清楚。当以500 Ci的强度和0.54戈伊/min的剂量率对来自钴源（Co-60）的胡芦巴干种子进行0.0、25、50、100和150戈瑞（戈伊）剂量的γ射线预播种时，显著降低叶绿素含量、总蛋白质、光合效率（（CO2）-C-14-固定）、总干重、减少的积累、非还原糖和总可溶性糖与未辐照对照相比。它还显着抑制水解酶（α-淀粉酶和转化酶），羧化酶（核酮糖-1，5-二磷酸羧化酶/加氧酶）在胡芦巴发达的植物。用甘氨酸甜菜碱（50 mM）浸泡辐照种子24 h，部分缓解了辐照对这些参数的抑制作用。γ-射线处理显著提高了H_2O_2含量。GB预浸辐照种子可显著降低H_2O_2含量。反转的幅度随辐照剂量的增加而减小。与未辐照对照相比，γ-辐照诱导了发育植物中核酸（DNA和RNA）水平的显著降低，并伴随着相应的DNA酶和RNA酶水解活性的诱导。这些变化在较高的伽马射线剂量下更为显著。用GB对辐照种子进行后处理可部分缓解辐射的不良影响。它显著增加核酸水平，抑制DNA酶和RNA酶的活性。甘氨酸甜菜碱的保护作用在低剂量γ射线照射下更为显著。GB预处理种子可能在辐射修复机制中发挥有效作用。
Irradiation stress adversely affects plant growth and development. The radio protective activity by glycinebetaine in plants has not been reported, and its mechanism has not been known. Gamma rays at doses 0.0, 25, 50, 100, and 150 Gray (Gy) when applied pre-sowingly to dry seeds of fenugreek from a cobalt source (Co-60) with strength of 500 Ci and the dose rate of 0.54 Gy/min significantly reduced chlorophyll content, total protein, photosynthetic efficiency ((CO2)-C-14-fixation), total dry weight, the accumulation of reducing, non-reducing and total soluble sugars in comparison with un-irradiated control. It also significantly repressed the activities of hydrolytic enzymes (alpha-amylase and invertase), the carboxylating enzyme (ribulose-1,5-bisphosphate-carboxylase/oxygenase) in the developed fenugreek plants. Soaking irradiated seeds with glycinebetaine (50 mM) for 24 h partially alleviated the depression effects of irradiation in these parameters. gamma-irradiation treatment increased significantly H2O2 content. Presoaking irradiated seeds with GB decreased significantly the H2O2 level. The magnitude of the reversal decreased with increasing the irradiation dose. gamma-irradiation induced a significant decrease in the level of nucleic acids (DNA and RNA) accompanied by a corresponding induction of hydrolytic activities of DNase and RNase in the developed plants in comparison with un-irradiated control. Those changes were more significant at higher gamma-ray doses. Post-treatment of irradiated seeds with GB partially alleviated the adverse effects of radiation. It significantly increased nucleic acid levels and repressed the activities of DNase and RNase. The protective role played by glycinebetaine was more significant at lower gamma-ray doses. Pretreatment of seeds with GB may play an effective role in the radio-repair mechanism.