Metabotyping: A New Approach to Investigate Rapeseed (Brassica napus L.) Genetic Diversity in the Metabolic Response to Clubroot Infection

Abstract

Clubroot disease affects all Brassicaceae spp. and is caused by the obligate biotroph pathogen Plasmodiophora brassicae. The development of galls on the root system is associated with the establishment of a new carbon metabolic sink. Here, we aimed to deepen our knowledge of the involvement of primary metabolism in the Brassica napus response to clubroot infection. We studied the dynamics and the diversity of the metabolic responses to the infection. Root system metabotyping was carried out for 18 rapeseed genotypes displaying different degrees of symptom severity, under inoculated and noninoculated conditions at 42 days postinoculation (dpi). Clubroot susceptibility was positively correlated with clubroot-induced accumulation of several amino acids. Although glucose and fructose accumulated in some genotypes with minor symptoms, their levels were negatively correlated to the disease index across the whole set of genotypes. The dynamics of the metabolic response were studied for the susceptible genotype 'Yudal,' which allowed an "early" metabolic response (established from 14 to 28 dpi) to be differentiated from a "late" response (from 35 dpi). We discuss the early accumulation of amino acids in the context of the establishment of a nitrogen metabolic sink and the hypothetical biological role of the accumulation of glutathione and S-methylcysteine.

Partial resistance to clubroot in Arabidopsis is based on changes in the host primary metabolism and targeted cell division and expansion capacity

“…However, several gene regulations related to photosynthesis and starch degradation suggest that the consequences on host primary metabolism were more dramatic in the susceptible response than in the partial resistance one. Consistent with these observations, Wagner et al (2012) showed in B. napus that the primary metabolism of resistant genotypes was not much affected compared to susceptible ones in response to P. brassicae infection. Hence, the partial resistance response may be associated with a reduced or delayed metabolic diversion by the pathogen.…”

Transcriptome Analysis of Arabidopsis thaliana in Response to Plasmodiophora brassicae during Early Infection

“…Using transcriptome analysis, Chen et al observed major changes between sensitive and resistant varieties of Brassica rapa 0–96 h post-infection in metabolism, transport, and signal transduction (Chen et al, 2015). Nowadays, new high-throughput technologies are gradually being used to study the interaction between P. brassicae and the host, such as metabotyping, laser microdissection coupled to transcriptional profiling coupled and miRNA sequencing (Wagner et al, 2012; Schuller et al, 2014; Verma et al, 2014). The P. brassicae genome was recently sequenced, which will be very convenient for studies on the interaction between host plants and P. brassicae in the future (Schwelm et al, 2015; Rolfe et al, 2016).…”

Research fields, challenges and opportunities in European oilseed crops breeding

“…Research and breeding programs have been developed with the aim to develop WOSR resistance toward clubroot caused by Plasmodiophora brassicae (Wagner et al, 2012). Genetic solutions, as well as crop management practices (Desanlys et al, 2013) were successfully developed from 1985 to make the sunflower fields poorly affected or even nearly resistant to Phomopsis due to Diaporthe helianthi.…”