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
Department of Agronomy, MNS University of Agriculture, Multan, Pakistan.
Department of Agronomy, UCA & ES, The Islamia University of Bahawalpur, Pakistan.
J Sci Food Agric. 2017 Nov;97(14):4780-4789. doi: 10.1002/jsfa.8347. Epub 2017 May 5.
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.
农业土壤中铅（Pb）的积累已成为作物减产的主要因素，并对食用农产品的人类构成严重威胁。本研究调查了硝酸钾种子引发（0和0.5%硝酸钾）对暴露于铅毒性（0、1300和2550毫克/千克铅）下的玉米（Zea mays L.）幼苗生长的影响。
铅暴露显著降低了玉米幼苗的生长，并导致根部的铅积累高于地上部分。用硝酸钾预处理种子显著提高了发芽率并增加了生理指标。还观察到硝酸钾种子引发对铅胁迫植物的色素（叶绿素a、b、总叶绿素和类胡萝卜素含量）有刺激作用。与地上部分相比，铅从根部向地上部分的低转运导致根部总游离氨基酸积累增加，过氧化氢酶、过氧化物酶、超氧化物歧化酶和抗坏血酸过氧化物酶的活性更高，而外源供应硝酸钾进一步增强了这些酶的活性以防止铅毒性。
在生长早期，玉米根部积累的铅比地上部分多。用硝酸钾引发种子可防止铅毒性，这可用于改善在铅污染土壤中生长的作物品种的幼苗建立。©2017化学工业协会。
