外源丙三醇对干旱胁迫下玉米幼苗抗逆调控作用

以郑单958幼苗为试验材料，设置空白对照(CK)、正常水分条件下1 mmol/L丙三醇(Gly)处理玉米幼苗叶片、20%聚乙二醇(PEG-6000)模拟干旱胁迫(PEG)、20%聚乙二醇模拟干旱胁迫+1 mmol/L丙三醇(PEG+Gly)处理玉米幼苗叶片4个处理展开试验。结果表明，干旱胁迫下外源施用1 mmol/L丙三醇能显著提高叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性；丙二醛(MDA)和过氧化氢(H₂O₂)积累减少；最大光量子效率(F_v/F_m)和光系统Ⅱ潜在活性(F_v/F_o)显著提高，玉米幼苗叶片的净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r)、相对含水率及生长指标均显著提高，胞间CO₂浓度(C_i)降低。因此，外源施用丙三醇能通过降低叶片的氧化损伤和提高细胞保水能力来改善...

Effect of Exogenous Glycerol on Physiological Regulation of Maize Seedlings under Drought Stress

Zhengdan958 seedlings were used as experimental materials. Four treatments were set up: blank control(CK), 1mM glycerol(Gly) treatment of maize seedling leaves under normal water conditions, 20% polyethylene glycol(PEG-6000) simulation of drought stress(PEG), 20% polyethylene glycol simulation of drought stress+1mM glycerol(PEG+Gly) treatment of maize seedling leaves. The results showed that the application of 1mM glycerol under drought stress could significantly increase the activities of superoxide dismutase(SOD), peroxidase(POD), catalase(CAT) and ascorbic acid peroxidase(APX). The 1mM glycerol treatment also reduced the accumulation of malondialdehyde(MDA) and hydrogen peroxide(H₂O₂). Exogenous glycerol significantly increased the maximum photo quantum efficiency(F_v/F_m) and the potential activity of photosystem II(F_v/F_o). Exogenous glycerol also significantly increase the net photosynthetic rate(P_n), stomatal conductance(G_s), transpiration rate(T_r), relative water contentd and growth target of maize seedlings under drought stress. The intercellular CO₂ concentration(C_i) was lower than that of PEG treatment. Therefore, exogenous application of glycerol can improve the adaptability of leaves to drought stress by reducing the oxidative damage of leaves and improving the water retention capacity of cells, thus improving the drought resistance of maize seedlings.