Consequences of SOS1 deficiency: intracellular physiology and transcription

Abstract

As much as there is known about the function of the sodium/proton antiporter SOS1 in plants, recent studies point towards a more general role for this protein. The crucial involvement in salt stress protection is clearly one of its functions -confined to the N-terminus, but the modular structure of the protein includes a segment with several domains that are functionally not studied but comprise more than half of the protein's length. Additional functions of the protein appear to be an influence on vesicle trafficking, vacuolar pH and general ion homeostasis during salt stress. Eliminating SOS1 leads to the expression of genes that are not strictly salinity stress related. Functions that are regulated in sos1 mutants included pathogen responses, and effects on circadian rhythm.

Figure 1

Transcriptional network associated with ATCN GC19. The transcriptional network records correlation of expression using an algorithm that establishes partial correlation between the expression characteristics of any pair of genes in relation to the correlation of these genes with all other genes in the dataset. The figure shows the network at the highest level of stringency that sorted some 9,000 genes into a network. When probing for correlations of genes with ATCNGC19, the resulting network graph showed the presence of genes in functional categories that are related to disease resistance, protein turnover, auxin metabolism, and redox/ethylene signaling, next to a surprisingly large number of functionally unknown genes. Information about the network and lists of genes can be retrieved by using the command ‘sub(“ATCN GC19”,2)’ in the R-based GGM workspace included in Ma et al.