Department of Plant Biology, Plant Pathology Section, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
Mol Plant Pathol. 2002 May 1;3(3):135-44. doi: 10.1046/j.1364-3703.2002.00105.x.
Summary Two barley (Hordeum vulgare L.) cDNA clones (pBH6-12 and pBH6-17) were isolated from a cDNA library prepared from leaves 6 h after inoculation with Blumeria graminis f.sp. hordei (Bgh). The two transcripts accumulate strongly in response to Bgh, peaking around 6, 15-24 and 48-96 h after inoculation, concomitant with fungal penetration attempts, hypersensitive response and fungal growth. The encoded proteins, HvPR-17a and HvPR-17b, belong to a new family of plant pathogenesis-related proteins, designated 'PR-17'. The family also include NtPRp27 from tobacco (Okushima et al., 2000, Plant Mol. Biol.42, 479-488) and WCI-5 from wheat (Görlach et al., 1996, Plant Cell8, 629-643), responsive to viral and fungal infection, respectively. Antisera were raised to HvPR-17a and HvPR-17b, and the proteins exhibit apparent molecular weights of 26 and 24 kDa, respectively. They accumulate in the mesophyll apoplast following Bgh-inoculation, as well as in the leaf epidermis, the only tissue to be invaded by the fungus. Several homologous plant proteins exist, and a highly conserved part of the members of this new protein family show similarity to the active site and to the peptide-binding groove of the exopeptidase 'aminopeptidase N' from eukaryotes and the endopeptidase 'thermolysin' from bacteria.
摘要 从接种禾本科布氏白粉病菌（Bgh）后 6 小时的叶片 cDNA 文库中分离出两个大麦（Hordeum vulgare L.）cDNA 克隆（pBH6-12 和 pBH6-17）。两种转录物在受到 Bgh 刺激后强烈积累，在接种后 6、15-24 和 48-96 小时达到峰值，与真菌穿透尝试、过敏反应和真菌生长同时发生。编码的蛋白质 HvPR-17a 和 HvPR-17b 属于植物病程相关蛋白的一个新家族，命名为'PR-17'。该家族还包括烟草中的 NtPRp27（Okushima 等人，2000 年，植物分子生物学 42，479-488）和小麦中的 WCI-5（Görlach 等人，1996 年，植物细胞 8，629-643），分别对病毒和真菌感染有反应。针对 HvPR-17a 和 HvPR-17b 制备了抗血清，两种蛋白质的表观分子量分别为 26 和 24 kDa。它们在 Bgh 接种后在叶肉质外质体中积累，以及在叶片表皮中积累，表皮是唯一被真菌侵袭的组织。存在几种同源植物蛋白，该新蛋白家族成员的高度保守部分与真核生物外肽酶“氨肽酶 N”和细菌内肽酶“耐热素”的活性位点和肽结合槽具有相似性。
