MsEnod12A Expression Is Linked to Meristematic Activity During Development of Indeterminate and Determinate Nodules and Roots

Molecular Plant-Microbe Interactions

关键词: auxins;    early nodulin;    Medicago;    Lotus;    Rhizobium;    gusA reporter gene;   

DOI  :  10.1094/MPMI.1997.10.1.39

来源: DOAJ

【 摘 要 】

During development of nodules and roots, the alfalfa early nodulin gene MsEnod12A is expressed adjacent to the meristem. Using transgenic alfalfa carrying a MsEnod12A promoter-gusA fusion, we investigated the regulation of MsEnod12A expression in mature nodules and roots by GUS assays and reverse transcription-PCR. We found that in alfalfa indeterminate nodules induced by various Fix- Rhizobium meliloti mutants and in spontaneous nodules devoid of rhizobia, MsEnod12A was expressed at the distal end when a persistent meristem was present. However, this gene was not expressed when the meristem was lacking in nodules arrested in development. The MsEnod12A-gusA fusion was introduced into Lotus corniculatus plants that form determinate nodules devoid of a persistent meristem. Using these plants we found MsEnod12A-gusA expression only in young nodules and a disappearance in mature nodules. Moreover, when alfalfa roots were treated with auxins a lateral band of MsEnod12A expression was observed surrounding the club-shaped root apex and coinciding with induced lateral meristematic activities. Thus, in all cases MsEnod12A expression was associated with meristematic activities, suggesting that MsEnod12A plays a role in the differentiation processes of nodule and root cells and that it may serve as molecular tool for analyzing meristem establishment during nodule development.

【 授权许可】

Unknown