Antoine Gravot,2,6 and
Maria J. Manzanares-Dauleux1,2
1AGROCAMPUS OUEST, UMR1349 IGEPP, F-35042 Rennes, France; 2Université Européenne de Bretagne, France; 3INRA, UMR1349 IGEPP, F-35653 Le Rheu, France; 4Institut de Biologie Moléculaire des Plantes, CNRS-UPR2357, F-67084 Strasbourg, France; 5Institut Sophia Agrobiotech UMR INRA 1355–CNRS 7254-Université de Nice-Sophia Antipolis, F-06903 Sophia-Antipolis, France; 6Université Rennes 1, UMR1349 IGEPP, F-35000 Rennes, France
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Accepted 6 July 2012.
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.
This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 2012.