Methods for identifying one or more amino acid substitutions in an oxalate oxidase (OXOX) variant polypeptide that confer maintained or increased OXOX activity are described herein. Methods and compositions for increasing a plants resistance to a pathogen using the modified OXOX variant polypeptides are provided. Transformed plants, plant cell, tissues, seed, and expression vectors are also provided. Methods for identifying one or more amino acid substitutions in an oxalate oxidase (OXOX) variant polypeptide that confer maintained or increased OXOX activity are described herein. Methods and compositions for increasing a plants resistance to a pathogen using the modified OXOX variant polypeptides are provided. Transformed plants, plant cell, tissues, seed, and expression vectors are also provided. A graft device is provided comprising a flow conduit and a surrounding covering. The graft device can connect a first body space and a second body space. In one embodiment, the flow conduit is a vein, such as a harvested saphenous vein, useful as an arterial graft, for example and without limitation, in a coronary artery bypass procedure. Also provided are methods of preparing a graft device and connecting the graft device between a first body space and a second body space, such as the aorta and a location on an occluded coronary artery, distal to the occlusion.Se describen en la presente métodos para identificar una o más sustituciones de aminoácido en un polipéptido variante de oxalato oxidasa (OXOX) que confieren actividad de OXOX mantenida o incrementada. Se proporcionan métodos y composiciones para incrementar la resistencia de una planta a un patógeno usando los polipéptidos variantes de OXOX. También se proporcionan plantas, célula de planta, tejidos, semilla y vectores de expresión transformados.
