Total RNA extraction from strawberry tree (Arbutus unedo) and several other woody-plants

Studies of plant gene expression today need pure preparations of high-yielding undegraded RNA. This is not easily accomplished when working with plants and tissues like strawberry tree (Arbutus unedo) leaves that accumulate large amounts of polysaccharides and polyphenolic compounds, which co-purify with RNA. An improved leaf-tissue protocol developed for gene expression studies on Arbutus unedo yields for the first time a purity of RNA extract that makes possible cDNA synthesis and qPCR analysis in this plant species. When tested on material considered recalcitrant (leaves, roots, fruit flesh, fruit peel and styles from Pyrus communis, Prunus avium, Prunus persica and Cydonia oblonga), the method was able to extract RNA with good yield and high purity. This scalable, phenol-free, fast and easy-to-use RNA extraction protocol is effective on Arbutus unedo leaves as well as on awide range of different species and tissues, thus resulting particularly useful for gene expression analysis in non-model species for molecular biology.