硅对盐胁迫下葡萄幼苗生理效应的影响

以酿酒葡萄"赤霞殊"(Cabernet Sauvignon,CS)1年生扦插苗为试材,采用营养液水培系统,研究了根施外源硅(K2SiO3·9H2O,Si)对盐(50 mmol/L NaCl)胁迫下赤霞珠葡萄幼苗叶片生理生化特性的影响.结果表明:盐胁迫处理下,葡萄幼苗叶片超氧阴离子(O2-')产生速率加快,过氧化氢(H2O2)、丙二醛(MDA)含量和相对膜透性增加;超氧化物歧化酶(SOD),过氧化物酶(POD)和过氧化氢酶(CAT)活性增强;组织含水量降低;施用2.0mmol/L Si明显抑制了O2-、H2O2和MDA的积累,增加了组织含水量,并进一步提高了抗氧化酶SOD和POD的活性.说明外源Si可通过提高盐胁迫下葡萄幼苗体内的抗氧化酶活性,从而降低活性氧(ROS)水平,一定程度上减轻盐胁迫对植株所造成的细胞膜脂过氧化伤害,增强其耐盐性.

Effects of exogenous silicon on physiological effect of Cabernet Sauvignon seedlings under salt stress

The effects of silicon (Si) on physiological effect of Cabernet Sauvignon seedlings were investigated under salt stress in a nutrient solution culture system. The results showed that the salt stress treatment increased the superoxide radical(O^-₂) production rate and the content of hydrogen peroxide (H₂O₂), leading to the accumulation of malonaldehyde(MDA) and the relative permeability of membrane was also higher, while the activities of antioxidant enzymes, including superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT), were promoted in seedlings. Exogenous 2.0 mmol/L Si treatment decreased significantly the content of MDA and O^-₂; and increased the activities of SOD and POD under salt stress. It indicates that exogenous 2.0 mmol/L Si treatment could alleviate the damage degree of 50 mmol/L NaCl stress through promoting antioxidant enzymes activities and suppressing ROS levels in seedlings under salt stress.