Bacterial glutathione is important to prevent early senescence in common bean nodules

MUGLIA, C., G. COMAI, E. SPEGAZZINI, P.M. RICCILLO, AND O. M. AGUILAR

FEMS MICROBIOLOGY LETTERS

Springer

Año: 2008 vol. 256 p. 191 - 198

0378-1097

In this paper we examine the importance of glutathione in symbiosis, using a7 glutathione biosynthetic gshB mutant derived of R. tropici CIAT899, a common bean8 (Phaseolus vulgaris) endosymbiont Plants infected with the mutant strain presented a9 delayed nodulation phenotype and a reduction in dry weight of aerial part of plants,10 suggesting diminished nitrogen fixation activity. In addition, bacterial gshB expression11 was assayed in wild type infected nodules, during the different steps of nodulation, and12 found to increase in mature and early senescent nodules. Conspicuously, nodules13 induced by gshB mutant bacteria presented early senescent pattern, which was14 associated to increased levels of superoxide accumulation.15 These results provide a direct evidence of the role of bacterial glutathione in protecting16 nodules from reactive oxygen species which may determine nodule senescence.