Bañuelos G S, Ajwa H A, Wu L, Guo X, Akohoue S, Zambrzuski S
USDA, ARS, Water Management Research Lab, Fresno, California 93727, USA.
Ecotoxicol Environ Saf. 1997 Apr;36(3):282-7. doi: 10.1006/eesa.1996.1517.
Brassica species considered for use in selenium (Se) phytoremediation need to accumulate large amounts of Se to be successful. Retarded plant growth and impaired protein synthesis are common symptoms for plants grown under seleniferous soils. Selenium accumulation by different land races of Brassica juncea (L.) Czern and Coss and one land race of Brassica carinata was investigated in Se-enriched water and soil cultures containing 2 mg Se kg-1. Effects of Se concentration in the root environment on the assimilation of Se, leaf surface area, dry matter yield, total leaf protein concentration, and free seleno-amino acid concentrations were analyzed for plants grown in Se-laden media. In water culture, shoot Se concentrations among the land races ranged from 501 to 1017 mg Se kg-1 dry matter (DM), and in plants grown in Se-laden soil, concentrations ranged from 407 to 769 mg Se kg-1 DM. Land races grown with Se exhibited decreases in dry matter yields from 12 to 23% and in leaf surface area from 5 to 26% compared to the same land races grown without Se. Protein content was significantly correlated both with shoot Se concentrations (r = 0.746, P < 0.001) and with leaf surface area (r = 0.446, P < 0.01) for all land races grown in Se-enriched water culture. There was also a significant correlation (r = 0.767, P < 0.001) between total Se assimilation and shoot protein for all land races. Free selenomethionine was detected for plants grown with Se and ranged from 92 to 958 ng g-1 DM. Other seleno-amino acids, Se-methyl-selenocysteine and selenocysteine, were not consistently detected as free amino acids in the different land races. Although visual symptoms of Se toxicity were not observed in the Brassica species, dry matter yield, leaf surface, and total shoot protein decreased, depending on the land races tested.
用于硒（Se）植物修复的芸苔属植物需要积累大量的硒才能成功。植物生长迟缓以及蛋白质合成受损是在富硒土壤中生长的植物常见的症状。在含2毫克硒/千克的富硒水培和土壤培养中，研究了不同地方品种的芥菜（Brassica juncea (L.) Czern and Coss）和一个埃塞俄比亚芥（Brassica carinata）地方品种对硒的积累情况。分析了根际环境中硒浓度对在富硒培养基中生长的植物的硒同化、叶面积、干物质产量、总叶蛋白浓度和游离硒氨基酸浓度的影响。在水培中，各地方品种地上部硒浓度范围为501至1017毫克硒/千克干物质（DM），在富硒土壤中生长的植物，其浓度范围为407至769毫克硒/千克DM。与不施硒生长的相同地方品种相比，施硒生长的地方品种干物质产量降低了12%至23%，叶面积降低了5%至26%。对于在富硒水培中生长的所有地方品种，蛋白质含量与地上部硒浓度（r = 0.746，P < 0.001）以及叶面积（r = 0.446，P < 0.01）均显著相关。所有地方品种的总硒同化与地上部蛋白质之间也存在显著相关性（r = 0.767，P < 0.001）。检测到施硒生长的植物中含有游离硒蛋氨酸，范围为92至958纳克/克DM。其他硒氨基酸，即硒甲基硒代半胱氨酸和硒代半胱氨酸，在不同地方品种中并非始终能检测到游离氨基酸形式。尽管在芸苔属植物中未观察到硒中毒的明显症状，但干物质产量、叶面积和地上部总蛋白均有所下降，这取决于所测试的地方品种。
