Determination of genes and phenotypes of bacteria necessary for epiphytic colonization and survival on plants
Bacteria that live as epiphytes on the surface of healthy plants are important as plant pathogens, in causing plant frost injury by catalyzing ice formation, and in other processes. The objectives of this study are to determine the traits of these epiphytic bacteria which allow them to grow and/or survive in the hostile leaf surface environment. The genes and phenotypes of a strain of Pseudomonas syringae that are necessary for epiphytic fitness on bean leaves are being determined by an evaluation of the fitness and phenotypes of 5300 individual Tn5-induced insertion mutants. Attention is being placed on several mutants which exhibit no known phenotypic alteration, but which while growing normally on moist leaf surfaces succumb to the stresses associated with dry leaf surfaces, unlike the parental strain. Two genes from stress-sensitive epiphytic fitness mutants that have individually large effects on fitness have been identified in a cosmid library of the parental P. syringae strain by sequence homology to Tn5-containing fragments cloned from mutant strains. A 4.0 kb region subcloned from one cosmid restores the ability of mutant strains to survive drying stress on leaves. Fusions of these regions with a promoterless InaZ gene have been made to determine the regulation of transcription of these regions in situ by measuring the ice nuclei produced in merodiploid strains containing these fusion genes. An Ice{sup {minus}} derivative of the parental P. syringae strain has been made by marker-exchange mutagenesis to allow measurements of ice nuclei in situ in these merodiploids exposed to different conditions on leaves. 11 figs., 1 tab.
- Research Organization:
- California Univ., Berkeley, CA (USA). Dept. of Plant Pathology
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- FG03-86ER13518
- OSTI ID:
- 6150634
- Report Number(s):
- DOE/ER/13518-5; ON: DE91008659
- Country of Publication:
- United States
- Language:
- English
Similar Records
Survival, growth, and localization of epiphytic fitness mutants of pseudomonas syringae on leaves
Comparison of the behavior of epiphytic fitness mutants of pseudomonas syringae under controlled and field conditions
Related Subjects
60 APPLIED LIFE SCIENCES
ICE
NUCLEATION
MUTANTS
COLONY FORMATION
PSEUDOMONAS
GENETIC ENGINEERING
TRANSPOSONS
MUTAGENESIS
BIOLOGICAL STRESS
BIOTECHNOLOGY
DNA HYBRIDIZATION
DNA-CLONING
GENE REGULATION
GENETIC MAPPING
GENOTYPE
LABELLING
LEAVES
MOLECULAR STRUCTURE
PHASEOLUS
PHENOTYPE
PHOSPHORUS 32
PROGRESS REPORT
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CLONING
DAYS LIVING RADIOISOTOPES
DOCUMENT TYPES
HYBRIDIZATION
ISOTOPES
LEGUMINOSAE
LIGHT NUCLEI
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MAPPING
MICROORGANISMS
NUCLEI
ODD-ODD NUCLEI
PHOSPHORUS ISOTOPES
PLANTS
RADIOISOTOPES
550400* - Genetics
550700 - Microbiology
553003 - Agriculture & Food Technology- Pest & Disease Control- (1987-)