Molecular and functional characterization of two RGA type genes in the PdR1b locus for Pierce’s disease resistance in Vitis arizonica/candicans

Abstract Pierce’s disease is a deadly of grapevines caused by the bacterial pathogen Xylella fastidiosa (Xf). A resistance locus from Vitis arizonica/candicans b43-17 segregated as single dominant gene and mapped PdR1a PdR1b in two F1 sibling selections. The physical mapping allele allowed identification five ORFs Leucine-Rich Repeat Receptor Kinase family. Two ORFs: V.ari-RGA14 V.ari-RGA18 were used to transform embryogenic callus V. vinifera Chardonnay (CH) Thompson Seedless (TS) rupestris St George (SG) via Agrobacterium tumefaciens . Regenerated plants inoculated with Xf under greenhouse conditions. Genetic transformation RGA14 18 did not generate CH TS, although some lines showed significantly lower stem concentration and/or exhibited reduced symptoms. In transgenic SG14, improved regrowth was accompanied titers decreased pectin lyase ß-1,3-glucanase 3 expression. limited effects transgenes on PD could be explained lack suitable partners or presence susceptibility factors that overcome these experimental involvement RGA17 should discarded.