Article Figures & Data
Figures
- Fig. 1.
Positions of transposon insertions in mutants used in this study. The cel and att regions of the bacterial chromosome are shown. Both of these regions have been sequenced (20, 21). An enlargement of the left end of theatt region is shown below the diagram of the larger clone. Triangles indicate the sites of transposon insertion in mutants used in this study. The small arrows with the triangles indicate the orientation of the promoterless β-galactosidase gene contained in Tn3HoHo1. The locations and directions of open reading frames (ORFs) are indicated by the larger arrows. The genes which have the highest homology to the open reading frames are indicated below the arrows (20, 21). Restriction sites are indicated as follows: E, EcoRI; C, ClaI; P, PstI; B,BamHI; X, XbaI; H, HindIII; S,SacI.
- Fig. 2.
Attachment of bacteria to A. thaliana root hairs. Wild-type and mutant A. tumefaciens strains were incubated with roots of A. thaliana in 0.4% sucrose for 2 days. (A) Wild-type strain C58. Note the numerous bacteria attached to the root hairs. (B) Cellulose-minus strain C58::1. (C) Attachment-minus mutant C58::A205. The attachment of thecel and att mutants was much reduced compared with the attachment of the wild type. Similar results were observed for bacteria attached to the root epidermis. Bar = 5 μm.
- Fig. 3.
Numbers of bacteria recovered from tomato roots. (A) Log10 total number of bacteria per centimeter of root length recovered from tomato roots inoculated with wild-type strain C58 (⧫) and cellulose-minus mutants C58::1 (▪) and C58::A60 (▵). (B) Log10 total number of bacteria per centimeter of root length recovered from tomato roots inoculated with wild-type strain C58 (⧫) and attachment-minus mutants C58::A205 (▪), C58::N004 (▵), and C58::B123 (×). Note that cellulose-minus and attachment-minus bacteria had reduced abilities to colonize roots. These reductions were due to reductions in loosely bound, tightly bound, and irreversibly bound bacteria. The numbers shown are the means from a minimum of four separate experiments. The standard deviation of all points was less than 0.9.
- Fig. 4.
Numbers of bacteria recovered from A. thaliana roots. (A) Log10 total number of bacteria per centimeter of root length recovered from A. thaliana roots inoculated with wild-type strain C58 (⧫) and cellulose-minus mutants C58::1 (▪) and C58::A60 (▵). (B) Log10 total number of bacteria per centimeter of root length recovered from A. thaliana roots inoculated with wild-type strain C58 (⧫) and attachment-minus mutants C58::A205 (▪) and C58::N004 (▵). Note that cellulose-minus and attachment-minus bacteria had reduced abilities to colonize the roots after the first day. The reductions in the total numbers of bacteria were due to reductions in loosely bound, tightly bound, and irreversibly bound bacteria. The numbers shown are the means from a minimum of four separate experiments. The standard deviation of all points was less than 0.5.
Tables
- Table 1.
Numbers of wild-type strain C58 bacteria associated with tomato roots after incubation in soil for up to 10 days
Day No. of bacteria (mean log10 ± SD)a Loosely bound Tightly bound Irreversibly bound 0 2.7 ± 0.7 2.6 ± 0.7 0.7 ± 0.6 1 2.3 ± 0.5 2.4 ± 0.6 0.2 ± 0.3 2 2.7 ± 0.5 2.7 ± 0.7 0.8 ± 0.5 3 3.7 ± 0.8 3.6 ± 0.8 1.5 ± 0.7 4 4.4 ± 0.4 4.3 ± 0.3 1.5 ± 0.6 5 4.8 ± 0.7 4.9 ± 0.5 1.4 ± 0.3 6 5.0 ± 0.5 5.0 ± 0.6 1.6 ± 0.3 7 4.8 ± 0.7 5.3 ± 0.8 3.0 ± 0.3 8 6.9 ± 0.9 6.6 ± 0.6 3.1 ± 0.3 9 7.7 ± 0.7 7.7 ± 0.7 3.7 ± 0.2 10 6.7 ± 0.5 6.9 ± 0.8 3.4 ± 0.3 ↵a The method used to determine the numbers of loosely bound, tightly bound, and irreversibly bound bacteria is described in the text.
- Table 2.
Numbers of cellulose-minus C58::1 bacteria associated with tomato roots after incubation in soil for up to 10 days
Day No. of bacteria (mean log10 ± SD)a Loosely bound Tightly bound Irreversibly bound 0 2.1 ± 0.3 2.0 ± 0.4 0.2 ± 0.2 1 2.4 ± 0.8 2.1 ± 1.1 0.2 ± 0.2 2 2.0 ± 0.4 2.1 ± 0.4 0.4 ± 0.4 3 2.3 ± 0.5 2.3 ± 0.7 0.5 ± 0.5 4 2.4 ± 0.4 2.0 ± 1.0 1.1 ± 0.9 5 2.2 ± 0.5 2.0 ± 0.4 0.5 ± 0.5 6 2.2 ± 0.5 2.4 ± 0.6 0.7 ± 0.5 7 2.5 ± 0.6 2.5 ± 0.6 0.7 ± 0.5 8 2.4 ± 0.6 2.5 ± 0.6 0.8 ± 0.6 9 2.6 ± 0.6 2.6 ± 0.6 1.3 ± 0.2 10 3.2 ± 0.1 2.7 ± 0.3 1.1 ± 0.5 ↵a The method used to determine the numbers of loosely bound, tightly bound, and irreversibly bound bacteria is described in the text.
