作者：Peris JE, Vicent A, Peña L.
作者单位：Instituto Valenciano de Investigaciones Agrarias (IVIA), Centro de Protección Vegetal y Biotecnología, Spain
摘要：Phytophthora spp. causes foot rot and gummosis, the most serious soilborne diseases of citrus worldwide. Sweet orange (Citrus sinensis) might be an excellent rootstock but it cannot be used as such in many citrus areas due to its high sensitivity to Phytophthora spp. The development of sweet orange that possess durable genetic resistance provides the best prospect for full recovery of this citrus type as rootstock. A wide range of plant defensive antifungal proteins has been identified and is being used in attempts to provide protection via expression in transgenic crops. Proteins of the PR-5 group (osmotin and thaumatin-like proteins) have antifungal activity in vitro against fungi and oomycetes. We demonstrated the antifungal properties of tomato P23 (PR-5) in vivo by overexpressing the PR-5 coding sequence under the control of the 35S promoter from CaMV in sweet orange plants, and testing plant response to P. citrophthora infections in excised bark pieces and in potted plants. One transgenic line (9.1a) resulted to be clearly resistant in both experiments, while other 9 (including 2.31a) resulted susceptible to P. citrophthora as the empty vector transgenic control (2.15). Promising results with transgenic line 9.1a encouraged us to conduct a field trial to test resistance to Phytophthora-induced foot rot. Transgenic sweet orange seedlings from lines 9.1a, 2.31a and 2.15 were used as rootstocks and non-transgenic clementine mandarin was budded on top and used as scion. Thirteen trees per transgenic event were randomly disposed in the field in 2009 and let to become naturally infected. Three years after planting, more than 50% of 2.31a and 2.15-trees are showing severe foot rot caused by Phytophthora, while all 9.1a trees remain symptomless.
文献注录：Peris JE, Vicent A, Peña L.. Transgenic sweet orange rootstocks overexpressing a osmotin like PR-5 protein show resistance against Phytophthora Foot Rot in the field [A]. [C] Ⅶ International Citrus Congress. 2012.
报/刊名：《》，发表于2012
文献类型： [A]
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