Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha, 40100, Pakistan.
Microelement Research Center, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Nov;24(31):24376-24386. doi: 10.1007/s11356-017-9977-2. Epub 2017 Sep 10.
Relations between phosphate and arsenate are important but inconsistent to influence arsenic (As) phytotoxicity depending on many plant and soil factors. Present research aimed to investigate the phosphate and arsenate interactions in sunflower (Helianthus annuus L.) grown in alkaline calcareous soil for 18 weeks under natural environmental conditions at three arsenate [0 (As), 40 (As), and 80 (As) mg As kg soil as sodium arsenate] and three phosphate [0 (P), 100 (P), and 200 (P) mg PO kg soil as diammonium phosphate] levels. The plants were grown in pots according to completely randomized design with five replications. Ionic and physiological parameters were measured at 40 days after treatment completion. Arsenic contamination with As and As increased root and shoot As concentration with relatively higher concentration in roots, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) while decreased plant P, chlorophyll, protein, and glutathione (GSH), and consequently plant growth, yield, and yield attributes. Addition of P and P under As stress reduced As transfer from soil to roots to shoots, MDA concentration, SOD, CAT, and POD activities while increased GSH, leaf protein, chlorophyll, and growth characteristics as well as achene yield compared to As-treated plants without additional P. In conclusion, P-induced inhibition of As transfer from soil to roots to shoots and reduction in MDA concentration accompanied with an increase in the synthesis of protein, chlorophyll, and GSH could be the main mechanisms responsible for lowered As toxicity in sunflower, leading to mitigation of potential risks of As contamination to food chain and human health.
磷酸盐和砷酸盐之间的关系很重要，但会受到许多植物和土壤因素的影响，从而影响砷（As）的植物毒性。本研究旨在调查向日葵（Helianthus annuus L.）在碱性石灰性土壤中生长的 18 周内，在自然环境条件下，三种砷酸盐 [0（As）、40（As）和 80（As）mg As kg 土壤，以砷酸钠形式存在] 和三种磷酸盐 [0（P）、100（P）和 200（P）mg PO kg 土壤，以磷酸二铵形式存在] 水平下，磷酸盐和砷酸盐的相互作用。根据完全随机设计，将植物种植在盆中，每个处理有五个重复。在处理完成后 40 天时测量离子和生理参数。砷污染导致 As 和 As 增加了根和地上部 As 的浓度，根部的浓度相对较高，同时增加了丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）的浓度，而降低了植物 P、叶绿素、蛋白质和谷胱甘肽（GSH）的浓度，从而导致植物生长、产量和产量性状下降。在 As 胁迫下添加 P 和 P 可减少 As 从土壤向根部向地上部的转移、MDA 浓度、SOD、CAT 和 POD 的活性，同时增加 GSH、叶蛋白、叶绿素和生长特性以及瘦果产量，与未添加 P 的 As 处理植物相比。总之，P 诱导的 As 从土壤向根部向地上部转移的抑制作用，MDA 浓度的降低以及蛋白质、叶绿素和 GSH 的合成增加，可能是向日葵降低 As 毒性的主要机制，从而降低了 As 对食物链和人类健康的潜在污染风险。
