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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #111089
Title: GENE TAGGING SYSTEMS FOR PCR-BASED MONITORING OF BACTERIA RELEASED FOR BIOLOGICAL CONTROL OF WEEDS

Author
item Schaad, Norman
item SONG, W - CHONBUK UNIVERSITY, KOREA
item HUTCHESON, STEVEN - UNIV. OF MARYLAND
item DANE, FENNY - AUBURN UNIV., ALABAMA

Submitted to: Canadian Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/4/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: Control of weeds result in application of more chemicals than for diseases or insects combined. In order to reduce the use of chemical herbicides without adversely affecting the sustainability of American agriculture, alternative weed control strategies are being developed. One alternative is the use of host-specific plant pathogens. The potential for use of natural pathogens is great, however, there is risk that useful crops or native plants might become infected. We have developed a stable, highly sensitive genetic-based gene tagging technique which will be used in assessing the risk of releasing plant pathogenic bacteria for biological control of weeds.

Technical Abstract: A prerequisite to release of any pathogen, regardless of origin, is a reliable method for its absolute identification from other strains. Several techniques are available including, lac ZY gene of E. coli, moc gene of Pseudomonas fluorescens, green fluorescent protein and lux gene. We have developed a PCR-based genomic scheme utilizina a 0.52 kb fatty acid desaturase (des) fragment of the unique tox-argK gene cluster of P. syringae pv. phaseolicola. The fragment is inserted into pGX15, a cosmid clone containing 10.3 kb EcoR1-HindIII fragment, including the pigG of the xanthomonadin gene of pig 102 to make pGXP6. A I0.8~7 fragment of pGXP6 is inserted into pLAFR3 to make pLXP22. The marked strain is constructed by inserting the 0.52 kb des fragment into a XmaI site within the pigG transcriptional unit on chromosomal DNA using pLXP22 and marker exchange. Results show that the des tagged strain is stable and easily identified by PCR.