| Title: | Harpin-induced expression and transgenic overexpression of the phloem protein gene AtPP2-A1 in Arabidopsis repress phloem feeding of the green peach aphid Myzus persicae |
| Author(s): | Zhang C; Shi H; Chen L; Wang X; Lu B; Zhang S; Liang Y; Liu R; Qian J; Sun W; You Z; Dong H; |
| Address: | "Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing 210095, PR China" |
| ISSN/ISBN: | 1471-2229 (Electronic) 1471-2229 (Linking) |
| Abstract: | "BACKGROUND: Treatment of plants with HrpNEa, a protein of harpin group produced by Gram-negative plant pathogenic bacteria, induces plant resistance to insect herbivores, including the green peach aphid Myzus persicae, a generalist phloem-feeding insect. Under attacks by phloem-feeding insects, plants defend themselves using the phloem-based defense mechanism, which is supposed to involve the phloem protein 2 (PP2), one of the most abundant proteins in the phloem sap. The purpose of this study was to obtain genetic evidence for the function of the Arabidopsis thaliana (Arabidopsis) PP2-encoding gene AtPP2-A1 in resistance to M. persicae when the plant was treated with HrpNEa and after the plant was transformed with AtPP2-A1. RESULTS: The electrical penetration graph technique was used to visualize the phloem-feeding activities of apterous agamic M. persicae females on leaves of Arabidopsis plants treated with HrpNEa and an inactive protein control, respectively. A repression of phloem feeding was induced by HrpNEa in wild-type (WT) Arabidopsis but not in atpp2-a1/E/142, the plant mutant that had a defect in the AtPP2-A1 gene, the most HrpNEa-responsive of 30 AtPP2 genes. In WT rather than atpp2-a1/E/142, the deterrent effect of HrpNEa treatment on the phloem-feeding activity accompanied an enhancement of AtPP2-A1 expression. In PP2OETAt (AtPP2-A1-overexpression transgenic Arabidopsis thaliana) plants, abundant amounts of the AtPP2-A1 gene transcript were detected in different organs, including leaves, stems, calyces, and petals. All these organs had a deterrent effect on the phloem-feeding activity compared with the same organs of the transgenic control plant. When a large-scale aphid population was monitored for 24 hours, there was a significant decrease in the number of aphids that colonized leaves of HrpNEa-treated WT and PP2OETAt plants, respectively, compared with control plants. CONCLUSIONS: The repression in phloem-feeding activities of M. persicae as a result of AtPP2-A1 overexpression, and as a deterrent effect of HrpNEa treatment in WT Arabidopsis rather than the atpp2-a1/E/142 mutant suggest that AtPP2-A1 plays a role in plant resistance to the insect, particularly at the phloem-feeding stage. The accompanied change of aphid population in leaf colonies suggests that the function of AtPP2-A1 is related to colonization of the plant" |
| Keywords: | "Animals Aphids/*physiology Arabidopsis/*genetics/parasitology Arabidopsis Proteins/*genetics/metabolism Bacterial Outer Membrane Proteins/*metabolism *Feeding Behavior Gene Expression Regulation, Plant Genes, Plant/genetics Glucuronidase Mutation/genetics;" |
| Notes: | "MedlineZhang, Chunling Shi, Haojie Chen, Lei Wang, Xiaomeng Lu, Beibei Zhang, Shuping Liang, Yuan Liu, Ruoxue Qian, Jun Sun, Weiwei You, Zhenzhen Dong, Hansong eng Research Support, Non-U.S. Gov't England 2011/01/14 BMC Plant Biol. 2011 Jan 13; 11:11. doi: 10.1186/1471-2229-11-11" |
