Characterization of four defense-related genes up-regulatedin root nodules of Casuarina glauca
2010 (English)In: Symbiosis, ISSN 0334-5114, Vol. 50, 25-35 p.Article in journal (Refereed) Published
Actinorhizal plants are capable of high rates ofnitrogen fixation, due to their capacity to establish a rootnodulesymbiosis with N2-fixing actinomycetes of the genus Frankia. Nodulation is an ontogenic process whichrequires a sequence of highly coordinated events. One of these mechanisms is the induction of defense-relatedevents, whose precise role during nodulation is largelyunknown. In order to contribute to the clarification of the involvement of defense-related genes during actinorhizal root-nodule symbiosis, we have analysed the differential expression of several genes with putative defense-relatedfunctions in Casuarina glauca nodules versus non inoculatedroots. Four genes encoding a chitinase (CgChi1), a glutathione S-transferase (CgGst), a hairpin-inducible protein (CgHin1) and a peroxidase (CgPox4) were found to be up-regulated in mature nodules compared to roots. In order to find out to which extend were the encoded proteins involved in nodule protection, development or both, generegulation studies in response to SA and wounding as wellas phylogenetic analysis of the protein sequences wereperformed. These were further characterized through expression studies after SA-treatment and wounding, and by phylogenetic analysis. We suggest that CgChi1 andCgGst are involved in defense or microsymbiont controland CgPox4 is involved in nodule development. For CgHin1 the question “defense, development or both” remains open.
Place, publisher, year, edition, pages
Springer , 2010. Vol. 50, 25-35 p.
Actinorhizal symbiosis . Casuarina glauca, Frankia, Defense, Chitinases, NHL, GST, Peroxidases
Research subject Plant Physiology
IdentifiersURN: urn:nbn:se:su:diva-54399DOI: 10.1007/s13199-009-0031-0OAI: oai:DiVA.org:su-54399DiVA: diva2:393690