CHARACTERIZATION AND SUBSTRATE INDUCED TRANSCRIPTIONAL REGULATION OF THE PENTAFUNCTIONAL AROM GENE OF RHIZOCTONIA SOLANI

Authors: Lakshman, Dilip; LIU, CHUNYU - BOSTON UNIV, BOSTON, MA; MISHRA, PRASHANT - UNIV OF CA, CALIFORNIA; TAVANTZIS, STELLOS - UNIV OF MAINE, ORONO, ME

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 3/23/2005
Publication Date: 6/10/2005
Citation: Lakshman, D.K., Liu, C., Mishra, P.K., Tavantzis, S.M. 2005. Characterization and substrate induced transcriptional regulation of the pentafunctional arom gene of Rhizoctonia solani. Phytopathology. 95:56.

Interpretive Summary:

Technical Abstract: The arom gene of the shikimate pathway is an intermediary in the aromatic amino acid production and a virulence regulatory element in the basidiomycete Rhizoctonia solani. The complete arom gene and its transcript from R. solani, anastomosis group 3 have been characterized. The gene consists of 5,323 base pairs including five introns. The upstream sequence has a GC box, and two GTATTAGA repeats. The largest isolated arom transcript is 5,108 nucleotides long. It contains an open reading frame of 4857 bases, coding for a putative 1618-residue pentafunctional AROM protein. A Kozak sequence (GCGCCATGG) is present between +127 and +135 bases. The 5’-end of the transcript includes two nucleotides (UA) that are not found in the genomic sequence. Size and sequence heterogeneity were observed at both 5’- and 3’-ends of the mRNA. Northern blot and suppression subtractive hybridization analyses showed that presence of a low amount of quinate, inducer of the quinate pathway, resulted in increased levels of arom mRNA, consistent with the compensation effect observed in ascomycetes. Phylogenetic analyses of the putative R. solani AROM protein with sixteen AROM proteins belonging to three groups of ascomycetes and two AROM proteins from other basidiomycetes correlated with the widely accepted fungal systematics schemes.