title: Effect of progressive drought stress on growth, leaf gas exchange, and antioxidant production in two maize cultivars.
abstract: Drought stress is one of the major environmental factors responsible for reduction in crop productivity. In the present study, responses of two maize cultivars (Rung Nong 35 and Dong Dan 80) were examined to explicate the growth, yield, leaf gas exchange, leaf water contents, osmolyte accumulation, membrane lipid peroxidation, and antioxidant activity under progressive drought stress. Maize cultivars were subjected to varying field capacities (FC) viz., well-watered (80 % FC) and drought-stressed (35 % FC) at 45 days after sowing. The effects of drought stress were analyzed at 5, 10, 15, 20, ad 25 days after drought stress (DAS) imposition. Under prolonged drought stress, Rung Nong 35 exhibited higher reduction in growth and yield as compared to Dong Dan 80. Maize cultivar Dong Dan 80 showed higher leaf relative water content (RWC), free proline, and total carbohydrate accumulation than Run Nong 35. Malondialdehyde (MDA) and superoxide anion were increased with prolongation of drought stress, with higher rates in cultivar Run Nong 35 than cultivar Dong Dan 80. Higher production of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and glutathione reductase (GR) resulted in improved growth and yield in Dong Dan 80. Overall, the cultivar Dong Dan 80 was better able to resist the detrimental effects of progressive drought stress as indicated by better growth and yield due to higher antioxidant enzymes, reduced lipid peroxidation, better accumulation of osmolytes, and maintenance of tissue water contents.
authors.affiliation: Engineering Research Center of South Upland Agriculture, Ministry of Education, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Agronomy and Biotechnology, Southwest University, Chongqing, 400716, China.|Department of Agronomy, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Shakeel Ahmad
authors.initials: SA
authors.lastname: Anjum
authors.affiliation: School of Land and Food, University of Tasmania, Hobart, Australia.
authors.forename: Mohsin
authors.initials: M
authors.lastname: Tanveer
authors.affiliation: Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China.
authors.forename: Umair
authors.initials: U
authors.lastname: Ashraf
authors.affiliation: College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Saddam
authors.initials: S
authors.lastname: Hussain
authors.affiliation: Department of Agronomy, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Babar
authors.initials: B
authors.lastname: Shahzad
authors.affiliation: Department of Agronomy, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Imran
authors.initials: I
authors.lastname: Khan
authors.affiliation: Engineering Research Center of South Upland Agriculture, Ministry of Education, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Agronomy and Biotechnology, Southwest University, Chongqing, 400716, China. wanglc@swu.edu.cn.
authors.forename: Longchang
authors.initials: L
authors.lastname: Wang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D055864:Droughts; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D014867:Water; D003313:Zea mays / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D014867:Water; D008315:Malondialdehyde; D011392:Proline; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase
keywords: Maize; Photosynthesis; Progressive drought stress; Proline accumulation; Yield