Characterization of Small Rubber Particle Protein 1 promoter from guayule (Parthenium argentatum)

Guayule (Parthenium argentatum) is a rubber producing plant. Genetic engineering of guayule to improve natural rubber content requires the use of promoters functional in stem tissues where most of guayule natural rubber is produced. We isolated a promoter region from a gene coding the Small Rubber Particle Protein 1. Transgenic guayule lines expressing the Small Rubber Particle Protein 1 promoter fused to β-glucuronidase reporter gene were developed. The promoter, active in leaf, stem and root tissues drives significant levels of transgene expression, especially in the stem tissue. The isolated Small Rubber Particle Protein 1 promoter is a new molecular element in the toolbox available for guayule improvement through genetic engineering strategies.