The antifungal Dm‐AMP1 protein from Dahlia merckii expressed in Solanum melongena is released in root exudates and differentially affects pathogenic fungi and mycorrhizal symbiosis

Abstract

Summary• Transformed aubergine plants constitutively expressing the Dm-AMP1 antimicrobial defensin (from Dahlia merckii ) were generated and characterized.• Transgenic plants were selected on kanamycin and screened by polymerase chain reaction analysis. The expression of Dm-AMP1 in plant tissues and its release in root exudates were detected by Western blot analyses. Dm-AMP1 localization was performed by immunohistochemical experiments.• Dm-AMP1 expression ranged from 0.2% to 0.48% of total soluble proteins in primary transformants and from 0.16% to 0.66% in F 2 plants. Transformed clones showed resistance to the pathogenic fungus Botrytis cinerea , whose development on leaves was reduced by 36-100%, with respect to controls. The protein was released in root exudates of the transformed plants and was active in reducing the growth of the co-cultured pathogenic fungus Verticillium albo-atrum , whereas it did not interfere with recognition responses and symbiosis establishment by the arbuscular mycorrhizal fungus Glomus mosseae .• Dm-AMP1 transformants may represent a useful model to study the interactions between genetically modified plants and pathogenic fungi or beneficial nontarget microorganisms.

Constitutive Expression of a Radish Defensin GeneRs-AFP2in Tomato Increases the Resisstance to Fungal Pathogens

“…the lowest levels of infection were observed in t1 and t14 both with size of the lesion 1.19 mm which was 68 % less compared to the control plants. Similar results were obtained in transgenic aubergine plants expressing defensin Dm-AMP1 originated from Dalia (Dahlia merckii) showed resistance to the pathogenic fungus Botrytis cinerea and the leaf infection was reduced by 36 to 100% (30).…”

Impact of Bt Corn on Rhizospheric and Soil Eubacterial Communities and on Beneficial Mycorrhizal Symbiosis in Experimental Microcosms

“…However, the cellular interactions between host roots and AM fungal hyphae leading to the failure of intraradical colonization in corn lines actively expressing the constitutive insecticidal B. thuringiensis toxin remain to be investigated. Previous works reported that transformed eggplant plants constitutively expressing the Dm-AMP1 antimicrobial defensin from Dahlia merckii releasing the protein in root exudates did not interfere with the host recognition system and symbiosis establishment by the AM fungus G. mosseae (74). Other authors have obtained similar findings, that transgenic Nicotiana sylvestris-and Nicotiana tabacum-expressing chitinases and pathogenesis-related proteins did not influence the establishment of mycorrhizal infection by G. mosseae (76,77).…”

Impact of Endochitinase-Transformed White Spruce on Soil Fungal Biomass and Ectendomycorrhizal Symbiosis

“…Crops, fruits, and forest trees exhibit mycorrhizal colonization by arbuscular mycorrhizae, ectomycorrhizae, and ectendomycorrhizae (EEM). While numerous studies have addressed the impact of transgenic plants on arbuscular mycorrhizae (10,26,64,68,72,73) and ectomycorrhizae (32,43,50,60), no previous study focused on EEM.…”