Over-expression of the Pseudomonas syringae harpin-encoding gene hrpZm confers enhanced tolerance to Phytophthora root and stem rot in transgenic soybean

Transgenic Research - Tập 27 - Trang 277-288 - 2018
Qian Du1,2, Xiangdong Yang2, Jinhua Zhang2, Xiaofang Zhong2, Kyung Seok Kim3, Jing Yang2, Guojie Xing2, Xiaoyu Li2, Zhaoyuan Jiang2, Qiyun Li2, Yingshan Dong2, Hongyu Pan1
1College of Plant Science, Jilin University, Changchun, China
2Jilin Academy of Agricultural Sciences, Changchun, China
3Iowa State University, Ames, USA

Tóm tắt

Phytophthora root and stem rot (PRR) caused by Phytophthora sojae is one of the most devastating diseases reducing soybean (Glycine max) production all over the world. Harpin proteins in many plant pathogenic bacteria were confirmed to enhance disease and insect resistance in crop plants. Here, a harpin protein-encoding gene hrpZpsta from the P. syringae pv. tabaci strain Psta218 was codon-optimized (renamed hrpZm) and introduced into soybean cultivars Williams 82 and Shennong 9 by Agrobacterium-mediated transformation. Three independent transgenic lines over-expressing hrpZm were obtained and exhibited stable and enhanced tolerance to P. sojae infection in T2–T4 generations compared to the non-transformed (NT) and empty vector (EV)-transformed plants. Quantitative real-time PCR (qRT-PCR) analysis revealed that the expression of salicylic acid-dependent genes PR1, PR12, and PAL, jasmonic acid-dependent gene PPO, and hypersensitive response (HR)-related genes GmNPR1 and RAR was significantly up-regulated after P. sojae inoculation. Moreover, the activities of defense-related enzymes such as phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO), peroxidase, and superoxide dismutase also increased significantly in the transgenic lines compared to the NT and EV-transformed plants after inoculation. Our results suggest that over-expression of the hrpZm gene significantly enhances PRR tolerance in soybean by eliciting resistance responses mediated by multiple defense signaling pathways, thus providing an alternative approach for development of soybean varieties with improved tolerance against the soil-borne pathogen PRR.

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