Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 7/15/2005
Publication Date: 9/24/2005
Citation: Yates, I.E., Mehrabi, L., Hinton, D.M., Bacon, C.W., Jaworski, A.J. 2005. Influence of water stress on emergence of fusarium verticillioides from corn plant tissues [abstract]. p2.101. Interpretive Summary: Abstract - InterDrought II - 2nd Int'l Conference on Integrated Approaches to Sustain and Improve Plant Production Under Drought Stress, Rome, Italy, 9/24-28/2005.
Technical Abstract: The fungus Fusarium verticillioides may exist in plants of corn (Zea Mays) in either a disease producing or a symptomless, endophytic association. Drought stress has been implicated in field studies as the stimulus for the outbreak of F. verticillioides disease symptoms in corn. The purpose of the current studies was to analyze the regulation of F. verticillioides distribution in corn plants grown under controlled environmental conditions in growth chambers. Drought stress was imposed on plants at three different ages of 1, 2, and 3 weeks after planting. Kernels of corn were artificially infected with a pathogenic strain of F. verticillioides, transformed with the plasmid carrying genes for the expression of beta-glucuronidase and hygromycin resistance. Control and drought-stressed plants were grown from F. verticillioides PATg-inoculated seed. All plants were analyzed at 4, 6, and 7 weeks after planting for growth, visible disease symptoms, and distribution of F. verticillioides in planta. At seven week after planting, growth was significantly reduced in all three drought stress treatment groups, but no disease symptoms were visible. In spite of the absence of disease expression, F. verticillioides PATg was isolated from all drought- stressed plants as well as the control plants. The fungus was more common in above ground parts of the plant in the control plants than the water stressed plants. Visible disease symptoms associated with classic stem rot were induced in drought stressed plants of all treatment groups by applying water to exceed maximum soil water holding capacity at seven weeks after planting.