Regulation of rhizosphere acidification by photosynthetic activity in cowpea (Vigna unguiculata L. walp.) seedlings.

ABSTRACT: In contrast to cereals or other crops, legumes are known to acidify the rhizosphere even when supplied with nitrates. This phenomenon has been attributed to N2 fixation allowing excess uptake of cations over anions; however, as we have found previously, the exposure of the shoot to illumination can cause rhizosphere acidification in the absence of N2 fixation in cowpea (Vigna unguiculata L. Walp). In this study, we examined whether the light-induced acidification can relate to photosynthetic activity and corresponding alterations in cation-anion uptake ratios. The changes of rhizosphere pH along the root axis were visualized using a pH indicator agar gel. The intensity of pH changes (alkalization/acidification) in the rhizosphere was expressed in proton fluxes, which were obtained by proce

SUBMITTER: Rao TP 

PROVIDER: S-EPMC4233795 | biostudies-literature | 2002 Feb

REPOSITORIES: biostudies-literature