Drought stress is a primary abiotic constraint affecting crop production worldwide. In this study, the role of exogenous spermidine (Spd) in conferring drought-stress-tolerance in maize (Zea mays L.) seedlings was studied by analysing polyamine metabolism and the antioxidant defence system. Two maize cultivars, Xianyu 335 (drought resistant) and Fenghe 1 (drought susceptible), were subjected to drought stress (–0.8 MPa) induced by 15% polyethylene glycol 6000 with or without Spd (0.1 mm) application. Spd significantly reduced the inhibition of plant growth and decreased malondialdehyde and hydrogen peroxide contents and the generation rate of oxidised glutathione caused by drought stress, particularly in Fenghe 1. The activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase further increased with the application of Spd to the stressed plants. Application of Spd significantly moderated the drought-induced reduction in activities of monodehydroascorbate reductase and dehydroascorbate and the ratio ascorbate : dehydroascorbate and reduced the ratio glutathione : oxidised glutathione. With the application of Spd, the contents of Spd and spermine and the activities of arginine decarboxylase, S-adenosyl methionine decarboxylase and diamine oxidase increased significantly in the stressed plants, and the increases were greater in Xianyu 335 than in Fenghe 1. Thus, exogenous Spd successfully reduced oxidative damage by enhancing the antioxidant components, raising the redox state of ascorbate and glutathione, and altering the polyamine pool, which play important roles in improving physiological characteristics and drought stress in maize.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 69 • No. 11