Seed priming with KNO 3 mediates biochemical processes to inhibit lead toxicity in maize (Zea mays L.)

• Published in: Journal of the science of food and agriculture 2017-11, Vol.97 (14), p.4780-4789
• Main Authors: Nawaz, Fahim, Naeem, Muhammad, Akram, Asim, Ashraf, Muhammad Y, Ahmad, Khawaja S, Zulfiqar, Bilal, Sardar, Hasan, Shabbir, Rana N, Majeed, Sadia, Shehzad, Muhammad A, Anwar, Irfan
• Format: Article
• Language: English
• Subjects: Antioxidants - analysis; Antioxidants - metabolism; Carotenoids - analysis; Chlorophyll - analysis; Food Contamination - prevention & control; Germination - drug effects; Lead - analysis; Lead - toxicity; Nitrates - pharmacology; Plant Roots - chemistry; Potassium Compounds - pharmacology; Seedlings - drug effects; Seedlings - growth & development; Seeds - drug effects; Seeds - growth & development; Soil Pollutants - analysis; Zea mays - drug effects; Zea mays - growth & development
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.8347

Accumulation of lead (Pb) in agricultural soils has become a major factor for reduced crop yields and poses serious threats to humans consuming agricultural products. The present study investigated the effects of KNO seed priming (0 and 0.5% KNO ) on growth of maize (Zea mays L.) seedlings exposed to Pb toxicity (0, 1300 and 2550 mg kg Pb). Pb exposure markedly reduced the growth of maize seedlings and resulted in higher Pb accumulation in roots than shoots. Pretreatment of seeds with KNO significantly improved the germination percentage and increased physiological indices. A stimulating effect of KNO seed priming was also observed on pigments (chlorophyll a, b, total chlorophyll and carotenoid contents) of Pb-stressed plants. Low translocation of Pb from roots to shoots caused an increased accumulation of total free amino acids and higher activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in roots as compared to shoot, which were further enhanced by exogenous KNO supply to prevent Pb toxicity. Maize accumulates more Pb in roots than shoot at early growth stages. Priming of seeds with KNO prevents Pb toxicity, which may be exploited to improve seedling establishment in crop species grown under Pb contaminated soils. © 2017 Society of Chemical Industry.