Induction of trehalase in Arabidopsis plants infected with the trehalose-producing pathogen Plasmodiophora brassicae.
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.
Botanisches Institut, Universität Basel, Switzerland.
Avid
A
Brodmann
Astrid
A
Schuller
Jutta
J
Ludwig-Müller
Roger A
RA
Aeschbacher
Andres
A
Wiemken
Thomas
T
Boller
Astrid
A
Wingler
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology* / Q000469:parasitology*; D001483:Base Sequence; D018076:DNA, Complementary; D004790:Enzyme Induction; D056890:Eukaryota / Q000235:genetics / Q000378:metabolism*; D005964:Glucosyltransferases / Q000235:genetics; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014198:Trehalase / Q000096:biosynthesis*; D014199:Trehalose / Q000096:biosynthesis* / Q000378:metabolism
D018076:DNA, Complementary; D014199:Trehalose; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase; D014198:Trehalase