Shao Xiao-Qing, He Zhang-Mi, Xu Wei-Hong
College of Resources and Environmental Sciences, Southwest University, Chongqing 400715, China.
Huan Jing Ke Xue. 2021 Feb 8;42(2):952-959. doi: 10.13227/j.hjkx.202007003.
Peppers are a high Cd-enriched vegetable. On the basis of a preliminary screening experiment of 91 pepper varieties and soil culture experiments during the entire growth period of 26 varieties, a high Cd variety (X15), medium Cd variety (X39), and two low varieties (X45 and X55) were selected to study the effect of different cadmium levels (0, 5, and 10 mg·kg Cd) on enrichment, transport, and accumulation as well as its subcellular distribution and chemical form. Based on the results, 5 mg·kg and 10 mg·kg of Cd inhibited shoot dry weights of four pepper varieties but increased the root dry weights of X15, X45, and X55 varieties. Sodium chloride-bound cadmium and acetate-bound cadmium are the main forms of cadmium in the pepper fruits. Subcellular cadmium concentrations in the roots, leaves, and fruits of pepper plants were ranked in order cytoplasm > cell wall > organelle, and in the stems the order was cell wall > cytoplasm > organelle. Cd compartmentalization plays an important role in pepper resistance to cadmium stress. Under dosages of 5 mg·kg Cd and 10 mg·kg Cd, Cd concentrations in stems and leaves were ranked in order X39 > X15 > X55 > X45, with fruit Cd concentrations ranked in order X15 > X39 > X55 > X45. The Cd concentration was lowest in the roots of X15 whereas this variety has the highest concentrations in its fruit. The Cd concentrations in the roots, stems, and leaves of X39 were the highest among the four varieties whereas the concentration in the fruit was lower than in the X15 variety. The concentration of Cd in pepper fruits depends on the Cd transport capacity redistribution ability to the shoots.
辣椒是一种镉富集程度较高的蔬菜。基于对91个辣椒品种的初步筛选试验以及26个品种整个生育期的土培试验，选取了一个高镉品种（X15）、一个中镉品种（X39）和两个低镉品种（X45和X55），研究不同镉水平（0、5和10 mg·kg镉）对镉的富集、转运、积累及其亚细胞分布和化学形态的影响。结果表明，5 mg·kg和10 mg·kg的镉抑制了4个辣椒品种地上部干重，但增加了X15、X45和X55品种的根部干重。氯化钠结合态镉和醋酸盐结合态镉是辣椒果实中镉的主要存在形式。辣椒植株根、叶和果实中的亚细胞镉浓度排序为细胞质＞细胞壁＞细胞器，而茎中的顺序为细胞壁＞细胞质＞细胞器。镉的区室化在辣椒对镉胁迫的抗性中起重要作用。在5 mg·kg镉和10 mg·kg镉处理下，茎和叶中的镉浓度排序为X39＞X15＞X55＞X45，果实镉浓度排序为X15＞X39＞X55＞X45。X15根部的镉浓度最低，而该品种果实中的镉浓度最高。在4个品种中，X39根、茎和叶中的镉浓度最高，而其果实中的浓度低于X15品种。辣椒果实中的镉浓度取决于镉向地上部的转运能力和重新分配能力。
