Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: August 12, 2000
Publication Date: N/A
Technical Abstract: Effective biological control strains of Trichoderma virens can induce the production of defense-related compounds in the roots of cotton. Ineffective strains do not induce these compounds to significant levels. This elicitation-activity is sensitive to proteinase treatment. When the active material was subjected to denaturing conditions and polyacrylamide gel electrophoresis, several bands were present in the material from biological control-active strains that were lacking in inactive strains. These bands were eluted and tested for elicitation activity, both with and without a renaturation step. Three bands stimulated cotton terpenoid production in at least 2 of three tests. One band of approximately 18kD, gave significant stimulation of cotton terpenoid production and increased peroxidase activity in cotton radicles in all tests. Activity was higher following renaturation, but occurred with denatured protein. The approximately 18kD protein was subjected to amino-terminal amino acid sequence analysis, and the first 19 amino acids at the amino terminus were determined to be DTVSYDTGYDNGSRSLNDV. A BLAST search showed similarity to a serine proteinase from Fusarium sporotrichioides, and two fungal protein precursors.