title: Unidirectional growth and branch formation of a morphological mutant, Agrobacterium tumefaciens.
abstract: Morphological characteristics of thermoconditional mutant Agrobacterium tumefaciens F-502 were investigated in relation to growth, division, and synthesis of cellular components. As a result of a shift from 27 to 37 C, mutant cells altered their morphology from short rods to elongated and branched forms; in addition, division and deoxyribonucleic acid synthesis were inhibited at 37 C. At 37 C unidirectional cell growth and branch formation occurred at one end of a cell, and the elongation rate of a cell was proportional to cell length. A hypothetical model for branch formation is presented in which the maximal elongation rate, 1.8 mum/h, at one end of a cell is an essential factor for initiation of branch formation.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002455:Cell Division; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D009154:Mutation; D010641:Phenotype; D010867:Pimelic Acids / Q000031:analogs & derivatives / Q000032:analysis; D012329:RNA, Bacterial / Q000032:analysis; D012231:Rhizobium / Q000032:analysis / Q000166:cytology* / Q000254:growth & development / Q000502:physiology; D013053:Spectrophotometry; D013696:Temperature; D013997:Time Factors
chemical_list: D000596:Amino Acids; D003470:Culture Media; D004269:DNA, Bacterial; D010867:Pimelic Acids; D012329:RNA, Bacterial