Abstract Detail
Symbioses: Plant, Animal, and Microbe Interactions Sarli, Adrian [1], Zdor, Robert [1]. Velvetleaf root colonization and plant growth effects by a noncyanogenic derivative of the weed deleterious rhizobacterium Pseudomonas putida ATH2-1RI/9. The use of weed deleterious rhizobacteria (WRB) in weed management strategies is an attractive component of sustainable agriculture. One such WRB, Pseudomonas putida ATH2-1RI/9, reduces velvetleaf plant growth upon root colonization and produces hydrogen cyanide (HCN) in the rhizosphere of colonized plants. A noncyanogenic derivative of this strain was constructed by insertion of a promoterless luxAB-npt gene cassette into the hcnABC operon. This derivative colonized velvetleaf roots grown in sterile soil to the same extent as the wild type strain (2 x 109 CFU/g dry root). A dual-plate assembly was used to test for the ability of bacterial volatiles to reduce velvetleaf growth. In this assembly bacteria grow in a shared atmosphere with velvetleaf seedlings but do not contact the plants. After 2 days of incubation, plant seedling growth was measured and cyanide recovered from the assembly quantified. As expected assemblies with the wild type strain contained HCN (1.1mM) and resulted in inhibited plant growth with velvetleaf root lengths being 42% of control plants. No HCN was recovered from assemblies containing the non-cyanogenic derivative. Interestingly root lengths of plants exposed to the derivative were 55% of control values. Browning was observed in roots exposed to either strain. These results suggest that volatile factors other than HCN may be involved in the deleterious effect Pseudomonas putida ATH2-1RI/9 has on velvetleaf growth.
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1 - Andrews University, Biology, Berrien Springs, MI, 49104, United States
Keywords:
velvetleaf
cyanide
weed biocontrol.
Presentation Type: Poster:Posters for Topics
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P78003
Abstract ID:1639 | 