Induction of Trehalase in Arabidopsis Plants Infected With the Trehalose-Producing Pathogen Plasmodiophora brassicae

Abstract

Various microorganisms produce the disaccharide trehalose during their symbiotic and pathogenic interactions with plants. Trehalose has strong effects on plant metabolism and growth; therefore, we became interested to study its possible role in the interaction of Arabidopsis thaliana with Plasmodiophora brassicae, the causal agent of clubroot disease. We found that trehalose accumulated strongly in the infected organs (i.e., the roots and hypocotyls) and, to a lesser extent, in the leaves and stems of infected plants. This accumulation pattern of trehalose correlated with the expression of a putative trehalose-6-phosphate synthase (EC 2.4.1.15) gene from P. brassicae, PbTPS1. Clubroot formation also resulted in an induction of the Arabidopsis trehalase gene, ATTRE1, and in a concomitant increase in trehalase (EC 3.2.1.28) activity in the roots and hypocotyls, but not in the leaves and stems of infected plants. Thus, induction of ATTRE1 expression was probably responsible for the increased trehalase activity. Trehalase activity increased before trehalose accumulated; therefore, it is unlikely that trehalase was induced by its substrate. The induction of trehalase may be part of the plant's defense response and may prevent excess accumulation of trehalose in the plant cells, where it could interfere with the regulation of carbon metabolism.

Genetic Analysis of Clubroot Resistance in Brassica Crops

“…This sugar is thought to be synthesized by the pathogen, and then released to the host cell, because putative gene for trehalose-6-phosphate synthase, an enzyme on the pathway of trehalose synthesis was detected in the pathogen. This sugar passively disturbs the sugar metabolism of the host plant (Brodmann et al 2002).…”

Overexpression of the Trehalase Gene AtTRE1 Leads to Increased Drought Stress Tolerance in Arabidopsis and Is Involved in Abscisic Acid-Induced Stomatal Closure

“…Transcriptional profiles and microarray data sets show that AtTRE1 expression is increased in vegetative tissues during senescence and is induced by auxin, cytokinin, sugar availability, and abiotic stresses such as drought (Müller et al, 2001b;Zimmermann et al, 2004;Brenner et al, 2005;Rolland et al, 2006). An important role for trehalase has been proposed during plant-microbe interactions in plants hosting trehalose-producing microorganisms, such as arbuscular mycorrhizal fungi, rhizobia, and the clubroot disease-inducing pathogen Plasmodiophora brassicae (Müller et al, 1994;Schubert and Wyss, 1995;Brodmann et al, 2002). Recently, an Attre1 knockout line was characterized (SALK_147073C; Alonso et al, 2003) and reported to have a 2-fold increase in T6P levels when grown on sorbitol (Delatte et al, 2011a).…”

Expression Profiling of Virulence and Pathogenicity Genes ofXanthomonas axonopodispv. citri

“…This gene codes for the enzyme trehalose-6-phosphate synthase involved in the synthesis of trehalose, a typical microbial sugar known to accumulate in a variety of symbiotic or pathogenic interactions of microorganisms with plants, as well as in response to salt stress (10,33). Trehalose-producing organisms could affect the carbon metabolism of infected plants by converting the products of photo- (32,34,54).…”