Cheng Yiran, Bao Yunjing, Chen Xing, Yao Qin, Wang Chao, Chai Songyue, Zeng Jian, Fan Xing, Kang Houyang, Sha Lina, Zhang Haiqin, Zhou Yonghong, Wang Yi
Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China.
College of Resources, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China.
J Hazard Mater. 2020 Dec 5;400:123209. doi: 10.1016/j.jhazmat.2020.123209. Epub 2020 Jun 17.
This study investigated the effects of different nitrogen (N) forms on Cadmium (Cd) uptake and accumulation in dwarf Polish wheat (DPW) seedlings, which were grown under Cd stress with N-Null, NH-N, NO-N and NH-N + NO-N. We measured plant growth and determined Cd uptake, translocation, accumulation, subcellular distribution and chemical forms in the roots and shoots of DPW seedlings. We also analyzed saccharide concentrations, and the transcript levels of genes encoding metal transporters in the roots of DPW seedlings. In the absence of NO-N, addition of NH-N reduced roots Cd concentration, F (Cd in cell wall), F (Cd in soluble fraction) and F (inorganic Cd) concentrations, and induced the expression of four genes encoding metal transporters in roots, while it promoted Cd translocation to shoots. In the presence of NO-N, addition of NH-N increased roots Cd concentration, F and F concentrations, and induced the expression of 22 genes encoding metal transporters in roots. Regardless of NH-N level, addition of NO-N increased roots Cd concentration, F, F, F (water-soluble Cd), F (pectates and protein Cd), F (undissolved Cd phosphate) and lactose concentrations, and also induced the expression of genes encoding metal transporters in roots. Overall, NH-N differently regulated Cd uptake and accumulation in DPW seedlings in the absence or presence of NO-N, while NO-N greatly increased Cd uptake and accumulation in the presence of NH-N compared to the absence of NH-N. These patterns of Cd alteration likely arose due to different N forms altering Cd subcellular distribution and chemical forms, lactose concentration and the expression of metal transporter genes.
本研究调查了不同氮（N）形态对矮秆波兰小麦（DPW）幼苗镉（Cd）吸收和积累的影响，这些幼苗在Cd胁迫下分别处于无氮、铵态氮、硝态氮以及铵态氮+硝态氮环境中生长。我们测定了植株生长情况，并确定了DPW幼苗根和地上部分中Cd的吸收、转运、积累、亚细胞分布及化学形态。我们还分析了糖类浓度以及DPW幼苗根中编码金属转运蛋白基因的转录水平。在没有硝态氮的情况下，添加铵态氮降低了根中Cd浓度、细胞壁中Cd的比例、可溶性部分中Cd的比例以及无机态Cd的浓度，并诱导根中四个编码金属转运蛋白的基因表达，同时促进了Cd向地上部分的转运。在有硝态氮的情况下，添加铵态氮增加了根中Cd浓度、细胞壁中Cd的比例以及可溶性部分中Cd的比例，并诱导根中22个编码金属转运蛋白的基因表达。无论铵态氮水平如何，添加硝态氮都会增加根中Cd浓度、细胞壁中Cd的比例、可溶性部分中Cd的比例、水溶性Cd的比例、果胶和蛋白质结合态Cd的比例、未溶解的磷酸镉的比例以及乳糖浓度，还会诱导根中编码金属转运蛋白的基因表达。总体而言，在没有或存在硝态氮的情况下，铵态氮对DPW幼苗中Cd的吸收和积累有不同的调节作用，而与不存在铵态氮相比，在存在铵态氮的情况下硝态氮极大地增加了Cd的吸收和积累。这些Cd变化模式可能是由于不同氮形态改变了Cd的亚细胞分布和化学形态、乳糖浓度以及金属转运蛋白基因的表达所致。
