CHROMIUM UPTAKE AND TRANSPORT IN BARLEY SEEDLINGS (HORDEUM-VULGARE-L)
CHROMIUM UPTAKE AND TRANSPORT IN BARLEY SEEDLINGS (HORDEUM-VULGARE-L)
复制标题
DOI：
10.1007/bf00399719
复制
发表时间：
1976-01-01
期刊：
影响因子：
4.3
通讯作者：
PETERSON, PJ
中科院分区：
文献类型：
--
作者：
SKEFFINGTON, RA;SHEWRY, PR;PETERSON, PJ
在溶液培养中，铬酸钾比氯化铬对大麦的生长毒性更大，尽管后者的表观吸收快得多。抑制剂研究表明，CrO 42-摄取是主动的，而Cr 3+摄取是被动的，表明这2种形式没有共同的摄取机制。对根细胞内Cr形式的研究表明，在饲喂CrO 42-的植物中，Cr基本保持不变，而在饲喂Cr 3+的植物中，产生少量CrO 42-（0.5%）。这种转化依赖于活物质的存在，并且可能是酶促的。在低浓度下，铬酸盐吸收遵循米氏动力学，并被硫酸盐竞争性抑制。铬向根部的运输非常缓慢，这是芽中铬含量低的原因。铬酸盐比Cr 3+更好地运输，尽管仍然在非常有限的程度上。这些实验为以前的观察提供了生理学基础。
Potassium chromate is more toxic to the growth of barley in solution culture than chromic chloride, though apparent uptake of the latter is much faster. Inhibitor studies indicate that CrO42- uptake is active whereas Cr3+ uptake is passive, demonstrating that the 2 forms do not share a common uptake mechanism. Studies on the form of Cr inside root cells show that in plants fed CrO42- the Cr remains largely unchanged whereas in plants fed Cr3+ a little CrO42- (0.5%) is produced. This conversion is dependent on the presence of living material and is probably enzymatic. Chromate uptake follows Michaelis-Menten kinetics at low concentration and is competitively inhibited by sulfate. Transport of Cr up the root is very slow, accounting for the low levels of Cr in the shoots. Chromate is transported better than Cr3+ though still to a very limited extent. These experiments provide a physiological basis for previous observations.