Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
College of Art Design, Yangzhou Polytechnic Institute, Yangzhou, 225107, Jiangsu, China.
Environ Sci Pollut Res Int. 2023 Jul;30(31):76735-76745. doi: 10.1007/s11356-023-27393-4. Epub 2023 May 29.
Cadmium (Cd) pollution threatens food security and the environment. Willow species (Salix, Salicaceae) exhibit a remarkable potential to restore Cd-polluted sites due to their high biomass production and high Cd accumulation capacities. This study examined the Cd accumulation and tolerance in 31 genotypes of shrub willow in hydroponic conditions at varying Cd levels (0 μM Cd, 5 μM Cd, and 20 μM Cd). The root, stem, and leaf biomass of 31 shrub willow genotypes showed significant differences to Cd exposure. Among 31 willow genotypes, four patterns of biomass variation response to Cd were identified: insensitive to Cd; growth inhibition due to excessive Cd supply (high Cd inhibition); low Cd causing inhibited growth, whereas high Cd leading to increased biomass (U-shape); and growth increment with excessive Cd exposure (high Cd induction). The genotypes belonging to the "insensitive to Cd" and/or "high Cd induction" were candidates for the utilization of phytoremediation. Based on the analysis of Cd accumulation of 31 shrub willow genotypes at high and low Cd levels, genotypes 2372, 51-3, and 1052 obtained from a cross between S. albertii and S. argyracea grew well and accumulated relatively more Cd levels than other genotypes. In addition, for Cd-treated seedlings, root Cd accumulation was positively correlated with shoot Cd accumulation and total Cd uptake, demonstrating that Cd accumulation in roots could serve as a biomarker for evaluating the Cd extraction capacity of willows, especially in hydroponics screening. The results of this study screened out willow genotypes with high Cd uptake and translocation capacities, which will provide valuable approaches for restoring Cd-contaminated soils with willows.
镉（Cd）污染威胁着食品安全和环境安全。柳树品种（柳属，杨柳科）由于其高生物量生产和高镉积累能力，在修复镉污染场地方面表现出巨大的潜力。本研究在不同镉水平（0 μM Cd、5 μM Cd 和 20 μM Cd）的水培条件下，研究了 31 种灌木柳的镉积累和耐受能力。31 种灌木柳基因型的根、茎和叶生物量对 Cd 暴露表现出显著差异。在 31 种柳属基因型中，确定了四种对 Cd 响应的生物量变化模式：对 Cd 不敏感；由于 Cd 供应过量而导致生长抑制（高 Cd 抑制）；低 Cd 导致生长抑制，而高 Cd 导致生物量增加（U 形）；以及过量 Cd 暴露导致生长增加（高 Cd 诱导）。属于“对 Cd 不敏感”和/或“高 Cd 诱导”的基因型是植物修复利用的候选者。根据对 31 种灌木柳基因型在高、低 Cd 水平下的 Cd 积累分析，来自阿尔泰柳和银柳杂交的 2372、51-3 和 1052 基因型生长良好，积累的 Cd 水平相对高于其他基因型。此外，对于 Cd 处理的幼苗，根 Cd 积累与地上部 Cd 积累和总 Cd 吸收呈正相关，表明根 Cd 积累可以作为评价柳树 Cd 提取能力的生物标志物，特别是在水培筛选中。本研究筛选出了具有高 Cd 吸收和转运能力的柳树基因型，这将为利用柳树修复 Cd 污染土壤提供有价值的方法。
