SMS and infection: In this sense, an A. thaliana mutant that overexpressed Sps gene, displayed higher resistance to infection with Pseudomonas viridiflava, whereas a mutant with low spermine levels showed hyper sensitivity; interestingly the over-expression of Sps was accompanied by up-regulation of genes involved in disease resistance protein, as well as several transcription factors (Cona et al., 2006; Kusano et al., 2008; Gonzalez et al., 2011).