Olivares, JE , Campos, Francisco , Estrada, G , Guillén, G , Alvarado-Affantranger, X , Díaz, C , Santana, O , Sanchez, F .
Genomics and RNAi Functional Analysis of a Highly Expressed Nod Gene Family in Phaseolus vulgaris.
Here, a genomic analysis and an RNAi reverse genetic approach, was used to unravel the biological function of a highly expressed nodulin gene family of Phaseolus vulgaris (bean). Genomic analysis indicated that one in five transcripts in the bean nodule EST data base reported by Ramirez et al, 2005 is encoded by gene members of the npv30 gene family. Highly expressed ESTs from nodule were also found expressed in the leaf cDNA library. Although Npv30 transcripts are very abundant, they encode 30-32 kDa proteins that are hardly detected by biochemical and immunological methods, suggesting that these proteins have a short half-life and/or its expression is strongly regulated at the translational level (Campos et al, 1995).npv30 transcripts show a ubiquitous localization but are mostly located in the infected cells from the bean nodule central zone. Surprisingly, Npv30 proteins were mostly immunolocalized in the neighboring uninfected cells, intercellular spaces around the infected cells and the vascular bundles. Npv30 proteins have N-terminal signal peptides suggesting that they are membrane-associated or secreted proteins. In addition, they have two regions with zinc finger-like motifs (Cys-X7-Cys). Finally, at the C-terminal end, all members have different tracks of prolines with variable lengths. Some members with large proline tracks are able to tightly bind profilin, an actin binding protein with a key role in the endocytic membrane pathway. We recently described that bean composite plants can be efficiently nodulated by rhizobia (Estrada et al., MPMI 19:1385-93, 2006). RNAi analysis in transgenic nodules suggests that the npv30 gene family has a role in repressing a default death pathway or has an anti-death function in root nodules. CONACYT 42562-Q and PAPIIT IN2084075 are acknowledged.
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1 - Instituto de Biotecnología, Universidad Nacional Autónoma de México, Biología Molecular de Plantas, Av. Universidad 2001, Chamilpa, Cuernavaca, Morelos, 62210, México
transgenic bean nodules
Bean nodulin function
default death pathway
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM