Transcription factors involved in senescence

Transcription factor in senescence

by Corrêa, L.G.G. and Riano-Pachón, D.M. at University of Potsdam

Introduction

Senescence is a highly regulated process, characterized by degradation of cellular components that would be redistributed to the whole plant. Some transcription factor have already been associated with the control of senescence and and a better understand of the networks, in which these transcription factors act, would lead to a better understanding of senescence itself. It has been also reported that genes involved in senescence are also involved in salt stress and wounding, but their controlling mechanism is still poorly understood.

Recently, Balazadeh et al. (2008, in press) identified 185 transcription factors differentially expressed during the later stages of leaf development, which could play a role at the onset of senescence. We performed phylogenetic analyzes for all families described in this paper in order to uncover their putative orthologues in Selaginella.

Methodology

Phlylogenetic analyses of transcription factor families were performed with sequences from Selaginella and Arabidopsis. Sequences were aligned by CLUSTALX (Thompson et al., 1997) and alignments were restricted to the respective conserved family domain. Neighbor-joining (NJ) trees were obtained using a JTT distance matrix with 1000 repetitions. NJ trees were computed with "neighbor" from the Software package PHYLIP (Felsenstein, 2005).

Results

We identified 43 transcription factors distributed among 11 different families. In some cases (i.e., AUX/IAA, C2H2, CCAAT, E2F-DP, MADS, SBP), no direct ortholog could be assigned. This could imply in a later recruitment of these families in the regulation of the onset of senescence.

Table 1: Putative Selaginella orthologs with Arabidopsis TFs that play a role in senescence

Contacts

Luiz Corrêa (correa [at] uni-potsdam.de)

Diego Riano-Pachon (diriano [at] uni-potsdam.de)