Copper availability and bioavailability are controlled by rhizosphere pH in rape grown in an acidic Cu-contaminated soil |
| |
Authors: | Valérie Chaignon |
| |
Institution: | INRA, UMR 1222 Eco&Sols Ecologie fonctionnelle & Biogéochimie des Sols (INRA-IRD-SupAgro), Place Viala, F-34060 Montpellier, France |
| |
Abstract: | We evaluated how root-induced changes in rhizosphere pH varied and interacted with Cu availability and bioavailability in an acidic soil. Rape was grown on a Cu-contaminated acidic soil, which had been limed at 10 rates. Soil Cu bioavailability was not influenced by liming. However, liming significantly decreased CaCl2-extracted Cu for pH between 3.7 and 5.1. Little effect was found for pH above 5.1. For soil pH < 4.4, CaCl2-Cu contents were smaller in rhizosphere than uncropped soil. Rhizosphere alkalisation occurred at pH < 4.8, while acidification occurred at greater pH. This explained the changes of CaCl2-Cu in the rhizosphere at low pH and the absence of pH dependency of Cu bioavailability to rape. In addition, apoplastic Cu in roots increased with increasing soil pH, most probably as a result of increased dissociation and affinity of cell wall compounds for Cu. |
| |
Keywords: | Brassica napus Copper Proton buffering capacity Proton flux Cell wall |
本文献已被 ScienceDirect 等数据库收录! |
|