Abstract Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) proteins that inhibit polygalacturonase (PG) enzymes secreted by pathogens to break down plant cell walls during early stage of disease development. Sugar beet (Beta vulgaris L.) PGIP genes (BvPGIPs) have 11 LRR domains as compared to 10 LRRs generally found in other plant species. To determine whether the BvPGIPs have a function in plant defense, genes encoding BvPGIP1 and BvPGIP2 that differ in 8 amino acids were fused with the CaMV 35S constitutive promoter and introduced into Nicotiana benthamiana. Crude PGIP protein extracts from BvPGIP1 transgenic plants significantly inhibited Rhizoctonia solani, Fusarium solani and Botrytis cinerea PGs. BvPGIP2 extract also inhibited PGs from F. solani and B. cinerea but did not inhibit PGs from R. solani. When transgenic BvPGIP plants were bioassayed for resistance, similar results were obtained. This is a first report that documents sugar beet PGIPs with 11 LRRs confer resistance to three different fungal pathogens.

中文翻译：

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具有 11 个 LRR 的甜菜多聚半乳糖醛酸酶抑制蛋白赋予烟草植物丝核菌、镰刀菌和葡萄孢属抗性

摘要 聚半乳糖醛酸酶抑制蛋白 (PGIP) 是富含亮氨酸的重复序列 (LRR) 蛋白，可抑制病原体分泌的聚半乳糖醛酸酶 (PG)，在疾病发展的早期阶段破坏植物细胞壁。甜菜 (Beta vulgaris L.) PGIP 基因 (BvPGIP) 具有 11 个 LRR 结构域，而其他植物物种中通常有 10 个 LRR。为了确定 BvPGIP 是否具有植物防御功能，将编码 BvPGIP1 和 BvPGIP2 的 8 个氨基酸不同的基因与 CaMV 35S 组成型启动子融合并引入本氏烟草中。来自 BvPGIP1 转基因植物的粗 PGIP 蛋白提取物显着抑制了立枯丝核菌、茄病镰刀菌和灰葡萄孢菌 PG。BvPGIP2 提取物也能抑制茄病菌和灰霉病菌的 PG，但不抑制茄病菌的 PG。当对转基因 BvPGIP 植物进行抗性生物测定时，获得了类似的结果。这是第一份报告，记录了具有 11 个 LRR 的甜菜 PGIP 赋予对三种不同真菌病原体的抗性。