Plant biology

Legume Symbiosome

Science Signaling  02 Mar 2010:
Vol. 3, Issue 111, pp. ec68
DOI: 10.1126/scisignal.3111ec68

Leguminous plants (peas and beans) are major players in globalnitrogen cycling by virtue of their symbioses with nitrogen-fixingbacteria that are harbored in specialized structures, callednodules, on the plant’s roots. Van de Velde et al. show that the host plant, Medicago truncatula, produces nodule-specificcysteine-rich peptides, resembling natural plant defense peptides.The peptides enter the bacterial cells and promote its developmentinto the mature symbiont. In a complementary study, Wanget al. have identified the signal peptidase, alsoencoded by the plant, that is required for processing thesespecialized peptides into their active form.

W. Van de Velde, G. Zehirov, A. Szatmari, M. Debreczeny, H. Ishihara, Z. Kevei, A. Farkas, K. Mikulass, A. Nagy, H. Tiricz, B. Satiat-Jeunemaître, B. Alunni, M. Bourge, K.-i. Kucho, M. Abe, A. Kereszt, G. Maroti, T. Uchiumi, E. Kondorosi, P. Mergaert, Plant peptides govern terminal differentiation of bacteria in symbiosis. Science 327, 1122–1126 (2010). [Abstract] [Full Text]

D. Wang, J. Griffitts, C. Starker, E. Fedorova, E. Limpens, S. Ivanov, T. Bisseling, S. Long, A nodule-specific protein secretory pathway required for nitrogen-fixing symbiosis.Science 327, 1126–1129 (2010). [Abstract] [Full Text]