Abstract

In vegetable production, Chinese cabbage can readily accumulate cadmium (Cd) into its edible parts and exceed food safety standards. However, there are still some ecotypes that respond differently to cadmium stress. This study aimed to investigate the differences of Cd-induced (0, 10, 50, 100, 200 µM) response under hydroponic culture between two Chinese cabbage ecotypes which were promoted in northeastern China from the characteristics of biomass, uptake kinetic, accumulation, and initial oxidative stress. In this paper, it was confirmed that Jinfeng (JF) was a Cd-tolerant cultivar and had low Cd accumulation in edible part, while Qiutian (QT) was Cd-sensitive, exhibiting a faster Cd uptake rate but lacking effective Cd detoxication mechanisms, and was severely damaged by 10 µM Cd treatment. Conversely, even at a high Cd concentration of 200 µM, Jinfeng had weaker biomass inhibition, lower root Cd affinity, more difficult root-to-leaf translocation, and stronger antioxidant enzyme activity than Qiutian. In conclusion, Jinfeng can endure mild Cd stress (<10 µM), and Qiutian can be used as a Cd indicator. This study provides reliable materials and related data support for vegetable production in areas with mild Cd pollution.

Novelty statement: This work further investigates the unique features of low-Cd accumulator in Chinese cabbage (Brassica pekinensis L.) seedlings as an interesting material for vegetable production in areas with mild Cd pollution. It also explains the differences between Cd-tolerant and Cd-sensitive cultivars under different cadmium stress levels and how these differences can alter their response. With the increase of Cd concentration, Cd-tolerant cultivars compared to Cd-sensitive cultivars showed less biomass decrease, lower accumulation, lower TF, more chemically stable Cd in roots and more active antioxidant enzymes under the same Cd stress level. With the development of seedlings, the uptake of Cd in roots and the translocation to the leaves were effectively restricted by the poor Cd affinity of roots, the conversion of Cd chemical forms and the promotion of antioxidase activities, in a Cd-tolerant low accumulator, Jinfeng.

摘要

在蔬菜生产中，大白菜很容易在其可食用部位积累镉（Cd）并超过食品安全标准。然而，仍有一些生态型对镉胁迫有不同的反应。本研究旨在从生物量、吸收动力学、积累、初始氧化应激。本文证实金凤（JF）是一个耐镉品种，在可食部分的镉积累量低，而秋田（QT）对镉敏感，表现出更快的镉吸收速度，但缺乏有效的镉解毒机制，并被 10 µM Cd 处理严重损坏。相反，即使在 200 µM 的高 Cd 浓度下，与秋田相比，金凤生物量抑制较弱，根系对镉的亲和力较低，根叶易位更难，抗氧化酶活性更强。综上所述，金峰可耐受轻度镉胁迫（<10 µM），秋田可作为镉指示剂。本研究为Cd轻度污染地区的蔬菜生产提供了可靠的材料和相关数据支持。

新颖性声明：这项工作进一步研究了大白菜（Brassica pekinensis）中低Cd蓄积体的独特特征。L.) 幼苗作为在轻度 Cd 污染地区用于蔬菜生产的有趣材料。它还解释了在不同镉胁迫水平下耐镉和镉敏感品种之间的差异，以及这些差异如何改变它们的反应。随着镉浓度的增加，与镉敏感品种相比，耐镉品种在相同的镉胁迫水平下表现出较少的生物量减少，较低的积累，较低的TF，根中的化学稳定性更高，抗氧化酶更活跃。随着幼苗的发育，在耐镉的低蓄积株中，根对镉的亲和力差、镉化学形态的转化和抗氧化酶活性的提高，有效地限制了根对镉的吸收和向叶的转运。金凤。