Plant biology

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Science's STKE  21 Jun 2005:
Vol. 2005, Issue 289, pp. tw231
DOI: 10.1126/stke.2892005tw231

Leguminous plants fix atmospheric nitrogen with the aid of symbiotic rhizobial bacteria. When Rhizobia infect the root, a complex developmental program is initiated to form the nodules that house the symbiotic bacteria (see the Perspective by Udvardi and Scheible). Smit et al. and Kaló et al. identify key elements in the signaling cascade by which the bacteria signal their presence to the host plants. The constitutively expressed plant proteins NSP1 and NSP2 are likely transcription factors poised to respond early to the bacterial nodulation factor signal. It appears that NSP1 and NSP2 respond to the initial nodulation factor-induced calcium signal to generate changes in gene transcription.

M. K. Udvardi, W.-R. Scheible, GRAS genes and the symbiotic green revolution. Science 308, 1749-1750 (2005). [Summary] [Full Text]

P. Smit, J. Raedts, V. Portyanko, F. Debellé, C. Gough, T. Bisseling, R. Geurts, NSP1 of the GRAS protein family is essential for rhizobial Nod factor-induced transcription. Science 308, 1789-1791 (2005). [Abstract] [Full Text]

P. Kaló, C. Gleason, A. Edwards, J. Marsh, R. M. Mitra, S. Hirsch, J. Jakab, S. Sims, S. R. Long, J. Rogers, G. B. Kiss, J. A. Downie, G. E. D. Oldroyd, Nodulation signaling in legumes requires NSP2, a member of the GRAS family of transcriptional regulators. Science 308, 1786-1789 (2005). [Abstract] [Full Text]