Identification and characterization of thaxtomin resistance genes in Arabidopsis, and genetic engineering of sacab-resistant potato

拟南芥中thaxtomin抗性基因的鉴定和表征以及抗sacab马铃薯的基因工程

• 批准号: 5424102
• 负责人: Professor Dr. Wolf-Rüdiger Scheible
• 金额: --
• 依托单位: Samuel Roberts Noble Foundation
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5424102?language=en
• 关键词: Identification; characterization; thaxtomin; resistance; genes

Thaxtomin A is a phytotoxin produced by Streptomyces scabies, the causal agent of scab disease in potato. Thaxtomin A causes cell-swelling phenotypes in many plant species, and experimental evidence suggests it acts as cellulose synthesis inhibitor. Several complementation groups of thaxtomin resistant (txr) Arabidopsis mutants have been isolated and we have already identified one of the TXR loci by recombinational mapping. The TXR1 gene encodes a novel, small protein of unknown function with homologs in all fully sequenced eukaryotic genomes. The txr1 mutant shows a strongly reduced uptake of thaxtomin A, suggesting that TXR1 is a component, or regulator of a transport mechanism. Experimental goals of the present proposal are (1) to genetically engineer scab resistance in potato by down-regulation of the potato TXR1 ortholog(s), (2) to identify the plant cell wall target and understand the mode-of-action of thaxtomin by identifying additional txr-loci, and by characterizing the metabolic and transcriptional responses of Arabidopsis after treatment with the phytotoxin, and (3) to further elucidate the biological function and to pinpoint the molecular partners of the evolutionarily conserved TXR1 protein.

Thaxtomin A 是由疥疮链霉菌产生的植物毒素，疥疮链霉菌是马铃薯疮痂病的病原体。 Thaxtomin A 会导致许多植物物种的细胞肿胀表型，实验证据表明它可作为纤维素合成抑制剂。 Thaxtomin 抗性 (txr) 拟南芥突变体的几个互补组已被分离出来，并且我们已经通过重组作图鉴定了 TXR 位点之一。 TXR1 基因编码一种功能未知的新型小蛋白，其在所有已完全测序的真核基因组中具有同源物。 txr1 突变体显示 thaxtomin A 的摄取大大减少，表明 TXR1 是转运机制的一个组成部分或调节器。本提案的实验目标是（1）通过下调马铃薯 TXR1 直系同源物来基因工程马铃薯的赤霉病抗性，（2）通过识别其他 txr 位点来识别植物细胞壁靶点并了解 thaxtomin 的作用模式，并通过表征拟南芥在用植物毒素处理后的代谢和转录反应，以及（3）进一步阐明 生物学功能并查明进化上保守的 TXR1 蛋白的分子伴侣。