Lin Kaina, Zeng Meng, Williams Darron V, Hu Weimin, Shabala Sergey, Zhou Meixue, Cao Fangbin
Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, China.
Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS, Australia.
iScience. 2022 Nov 3;25(12):105484. doi: 10.1016/j.isci.2022.105484. eCollection 2022 Dec 22.
Cadmium (Cd) pollution in soil has become a major environmental issue worldwide. However, the underlying molecular mechanism of low grain-Cd accumulation (GCA) in maize is still largely unknown. Herein, we report the mechanistic basis for low GCA in maize by a multiomics approach. The low GCA genotype L63 showed normal vacuolar formation and a lower capacity of xylem loading of Cd than the high-accumulator L42 under Cd stress. Transcriptomic sequencing identified 84 low-GCA-associated genes which are mainly involved in the S-adenosylmethionine (SAM) cycle, metal transport, and vacuolar sequestration. A metabolome analysis revealed that L63 plants had a more active SAM cycle and a greater capacity for terpenoid synthesis and phenylalanine metabolism than L42. Combining the analysis of transcriptome and metabolome characterized several genes as key genes involved in the determination of Cd accumulation. Our study identifies a mechanistic basis for low Cd accumulation in maize grains and provides candidate genes for genetic improvement of crops.
土壤中的镉（Cd）污染已成为全球主要的环境问题。然而，玉米籽粒低镉积累（GCA）的潜在分子机制仍 largely 未知。在此，我们通过多组学方法报道了玉米低 GCA 的机制基础。在 Cd 胁迫下，低 GCA 基因型 L63 显示出正常的液泡形成，且 Cd 的木质部装载能力低于高积累型 L42。转录组测序鉴定出 84 个与低 GCA 相关的基因，这些基因主要参与 S-腺苷甲硫氨酸（SAM）循环、金属转运和液泡隔离。代谢组分析表明，与 L42 相比，L63 植株具有更活跃的 SAM 循环以及更强的萜类合成和苯丙氨酸代谢能力。结合转录组和代谢组分析，确定了几个基因作为参与 Cd 积累决定的关键基因。我们的研究确定了玉米籽粒低 Cd 积累的机制基础，并为作物的遗传改良提供了候选基因。
