Transgenic citrus expressing the antimicrobial gene Attacin E (attE) reduces the susceptibility of ‘Duncan’ grapefruit to the citrus scab caused by Elsinoë fawcettii

Citrus scab, caused by Elsinoë fawcettii (anamorph Sphaceloma fawcettii ), is a common foliar fungal disease affecting many citrus cultivars, including grapefruit. No commercial grapefruit cultivar is resistant to scab, and the disease results in severely blemished fruit which reduces its marketability. Transgenic ‘Duncan’ grapefruit trees expressing the antimicrobial attE gene were produced via Agrobacterium -mediated transformation. In in vitro leaf and greenhouse assays, several transgenic-lines had significantly lower susceptibility to E. fawcettii compared to the non-transformed control ( P