Rice bacterial blight resistance in Burkina Faso through genome editing

Bacterial leaf blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), causes yield losses exceeding 50% in affected areas, including the Bagré rice plain in Burkina Faso. Genome-edited (GE'd) rice lines have been successful in tackling BB. Modifications in the Xoo virulence protein target site upstream of three SWEET susceptibility genes in two elite rice varieties, IR64 and Ci-herang-Sub1, have been demonstrated to confer broad-spectrum resistance to Asian and East African Xoo strains. Here, we evaluate the potential of the GE'd lines as a solution for BB man-agement in Burkina Faso. We challenged the GE'd lines against five locally collected Burkinabè Xoo strains under controlled greenhouse conditions and assessed their agro-morphological per-formance under field conditions representative of local agroecological conditions. Greenhouse pathogen assays demonstrated that GE'd IR64 and Ciherang-Sub1 lines were resistant to all tested local Xoo strains across three successive generations. We identified TalC as the primary dis-ease-causing effector in the local Xoo populations. Irrigated field trials conducted over two seasons in the Kou Valley, Burkina Faso, under natural disease pressure revealed absence of agro-morphological penalties in GE'd lines compared to their parental wild-type lines. Observed trait variation was attributable to environmental fluctuations rather than genomic modifications. Collectively, our findings demonstrate that genome editing of the rice lines does not impose growth penalties, and support the suitability of GE'd IR64 and Ciherang-Sub1 for large-scale adoption in Burkina Faso, pending multi-location validation and introgression into locally adapted varieties.