Abstract: Homologues of the Arabidopsis NIM1 gene, which is involved in the signal transduction cascade leading to systemic acquired resistance (SAR), are isolated from Nicotiana tabacum (tobacco), Lycopersicon esculentum (tomato), Brassica napus (oilseed rape), Arabidopsis thaliana, Beta vulgaris (sugarbeet), Helianthus annuus (sunflower), and Solanum tuberosum (potato). The invention further concerns transformation vectors and processes for expressing the NIM1 homologues in transgenic plants to increase SAR gene expression and enhance broad spectrum disease resistance.