Exogenous Application of Amino Acids Alleviates Toxicity in Two Chinese Cabbage Cultivars by Modulating Cadmium Distribution and Reducing Its Translocation

• Published in: International journal of molecular sciences 2024-08, Vol.25 (15), p.8478
• Main Authors: Li, Longcheng, Chen, Qing, Cui, Shihao, Ishfaq, Muhammad, Zhou, Lin, Zhou, Xue, Liu, Yanli, Peng, Yutao, Yu, Yifa, Wu, Wenliang
• Format: Article
• Language: English
• Subjects: Agricultural production; Amino acids; Amino Acids - metabolism; Biological Transport; Brassica - drug effects; Brassica - metabolism; Cadmium; Cadmium - metabolism; Cadmium - toxicity; cadmium translocation; chemical forms; Chinese cabbage; Chlorophyll; Cultivars; Gene Expression Regulation, Plant - drug effects; Leaves; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - drug effects; Plant Roots - metabolism; Plant Shoots - drug effects; Plant Shoots - metabolism; subcellular distribution; Toxicity; Vegetables
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms25158478

Plants communicate underground by secreting multiple amino acids (AAs) through their roots, triggering defense mechanisms against cadmium (Cd) stress. However, the specific roles of the individual AAs in Cd translocation and detoxification remain unclear. This study investigated how exogenous AAs influence Cd movement from the roots to the shoots in Cd-resistant and Cd-sensitive Chinese cabbage cultivars (Jingcui 60 and 16-7 cultivars). The results showed that methionine (Met) and cysteine (Cys) reduced Cd concentrations in the shoots of Jingcui 60 by approximately 44% and 52%, and in 16-7 by approximately 43% and 32%, respectively, compared to plants treated with Cd alone. However, threonine (Thr) and aspartic acid (Asp) did not show similar effects. Subcellular Cd distribution analysis revealed that AA supplementation increased Cd uptake in the roots, with Jingcui 60 preferentially storing more Cd in the cell wall, whereas the 16-7 cultivar exhibited higher Cd concentrations in the organelles. Moreover, Met and Cys promoted the formation of Cd-phosphate in the roots of Jingcui 60 and Cd-oxalate in the 16-7 cultivar, respectively. Further analysis showed that exogenous Cys inhibited Cd transport to the xylem by downregulating the expression of in the roots of both cultivars, and in the 16-7 cultivar. These findings provide insights into the influence of exogenous AAs on Cd partitioning and detoxification in Chinese cabbage plants.