Kiba Akinori, Nishihara Masahiro, Tsukatani Nobue, Nakatsuka Takashi, Kato Yoshiaki, Yamamura Saburo
Iwate Biotechnology Research Center, Kitakami, Iwate, 024-0003 Japan.
Plant Cell Physiol. 2005 Jun;46(6):1007-15. doi: 10.1093/pcp/pci109. Epub 2005 Apr 19.
An antifungal protein (GtAFP1) showing antimicrobial activity against phytopathogenic fungi was purified from leaves of Gentiana triflora. The deduced amino acid sequence of the cDNA of the corresponding gene, GtAFP1, showed 94, 75, 72 and 63% amino acid identities with peroxiredoxin Q from Populus balsamifera x P. deltoides subsp. trichocarpa, Sedum lineare, Suaeda maritima and Arabidopsis thaliana, respectively. The GtAFP1 gene is suggested to be present in the genome in one to two copies and was expressed in the leaves, roots and stems. Expression of GtAFP1 was induced by treatment with salicylic acid, but not methyl jasmonate. Recombinant GtAFP1 protein showed not only antifungal activity but also thioredoxin-dependent peroxidase activity. Overexpression of GtAFP1 in tobacco plants improved tolerance not only against fungal diseases but also against oxidative stress. These results indicate that GtAFP1 might act as a disease and oxidative stress defensive gene in plants and could be useful for engineering stress-resistant plants.
从三花龙胆叶片中纯化出一种对植物病原真菌具有抗菌活性的抗真菌蛋白（GtAFP1）。相应基因GtAFP1的cDNA推导的氨基酸序列与香脂杨×三角叶杨亚种毛果杨、佛甲草、盐地碱蓬和拟南芥的过氧化物氧还蛋白Q分别具有94%、75%、72%和63%的氨基酸同一性。推测GtAFP1基因在基因组中以1至2个拷贝存在，并在叶、根和茎中表达。水杨酸处理可诱导GtAFP1的表达，但茉莉酸甲酯处理则不能。重组GtAFP1蛋白不仅具有抗真菌活性，还具有硫氧还蛋白依赖性过氧化物酶活性。在烟草植株中过表达GtAFP1不仅提高了对真菌病害的耐受性，还提高了对氧化胁迫的耐受性。这些结果表明，GtAFP1可能在植物中作为一种疾病和氧化胁迫防御基因发挥作用，并且可能有助于培育抗逆性植物。
