干旱胁迫下水杨酸对红肉脐橙幼苗生理生化特性的影响

Effect of Salicylic Acid on the Physiology and Biochemistry of 'Cara Cara'' Navel Orange Seedlings under Drought Stress

以红肉脐橙[Citrus sinenisis(L.)Osbeck‘Cara Cara’']幼树为试材,采用4个水杨酸(SA)水平(0,0.1、0.5和2.5 mmol/L)叶面喷施并结合根部灌溉后进行干旱处理,清水正常灌溉为对照。对干旱胁迫过程中幼树叶片抗氧化酶、脂质过氧化产物、脯氨酸以及叶片相对含水量进行分析测定。结果表明:与正常灌水相比,干旱胁迫下,叶片丙二醛(MDA)含量增多,脯氨酸(Pro)积累增加,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性变化显著;另一方面,在干旱胁迫过程中,红肉脐橙经SA处理后叶片抗氧化酶SOD,POD、CAT活性以及渗透调节物质Pro的积累显著高于未用SA处理的叶片,同时,SA处理能显著降低叶片MDA含量。

The seedlings of ＇ cara cara＇ ＂navel orange （ Citrus sinenisis） are used to study the effect of salicylic acid （SA） （0, 0. 1, 0.5, 2.5 mmoL/L） on the antioxidant metabolism of Cara cara＇navel orange leaves under drought stress. Normal irrigation is taken as the contrast. The antioxidant enzyme, lipid peroxide production, praline（Pro） and relative water in Cara cara＂ navel orange leaves under drought stress are determined. The results show that the contents of malondialdehyde （MDA） and the Pro increase while the relative water in leaves decreases under drought stress. At the same time, the changes of superoxide dismutase （SOD）, Guaiacol peroxide （POD） and catalase （CAT） activity are significant under drought stress. On the other hand, the antioxidant enzyme （SOD, CAT and POD） activity and Pro content in the leaves of Cara eara＂ navel orange seedlings with SA are significantly higher than those without SA. Simultaneity, the MDA content in the leaves with SA - treatment reduces significantly in contrast to that without SA -treatment.