RESUMO
Quantitative disease resistance (QDR) based on PAMP-triggered immunity (PTI) could be durable and effective against many pathogens (broad spectrum). Development of methods to evaluate PTI responses in crops could therefore accelerate breeding for durable QDR. Most PTI-studies involved model plants such as Arabidopsis and Nicotiana benthamiana or cell cultures, and cannot be directly applied to diverse germplasm of crop plants.We developed methods to measure PTI in Brassica crop species (Lloyd et al., Mol Plant Microbe Interact 27:286-295, 2014) which we have elaborated and expanded here to enable their use for screening and evaluating germplasm for potential QDR in breeding programs.
Assuntos
Brassica/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Moléculas com Motivos Associados a Patógenos/imunologia , Espécies Reativas de Oxigênio/metabolismo , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Sistema de Sinalização das MAP Quinases , Proteínas Quinases Ativadas por Mitógeno/genética , Fosforilação , Doenças das Plantas/imunologia , Imunidade Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
The first layer of active defense in plants is based on the perception of pathogen-associated molecular patterns (PAMPs) leading to PAMP-triggered immunity (PTI). PTI is increasingly being investigated in crop plants, where it may have potential to provide durable disease resistance in the field. Limiting this work, however, is an absence of reliable bioassays to investigate PAMP responses in some species. Here, we present a series of methods to investigate PTI in Brassica napus. The assays allow measuring early responses such as the oxidative burst, mitogen-activated protein kinase phosphorylation, and PAMP-induced marker gene expression. Illumina-based RNA sequencing analysis produced a genome-wide survey of transcriptional changes upon PAMP treatment seen in both the A and C genomes of the allotetraploid B. napus. Later responses characterized include callose deposition and lignification at the cell wall, seedling growth inhibition, and PAMP-induced resistance to Pseudomonas syringae and Botrytis cinerea. Furthermore, using these assays, we demonstrated substantial variation in PAMP responses within a collection of diverse B. napus cultivars. The assays reported here could have widespread application in B. napus breeding and mapping programs to improve selection for broad-spectrum disease resistance.
