The isolates that differed in the plasmid pattern were assumed to be distinct strains. In all the strains studied, the single symbiotic plasmid (pSym), with PS-341 average molecular weight of 361 kb (ranging
from 260 kb to 500 kb) was identified by Southern hybridization with nodA and nifNE probes, derived from the R. leguminosarum bv. trifolii TA1 (RtTA1) laboratory strain [26]. A set of 24 strains (including RtTA1) with a highly variable number and size of plasmids was chosen for further hybridization assays. Noteworthy is the presence of very large plasmids with molecular weight above 1.0 Mb, identified in a majority of buy 3-MA the sampled strains (Figure 1). Figure 1 Plasmid profiles of selected R. leguminosarum bv. trifolii nodule isolates. (A) Profiles obtained in Eckhardt-type agarose gel electrophoresis; stars colored in green indicate Go6983 datasheet pSym plasmids. Lanes: 1-RtTA1; 2-Rlv 3841; 3-K2.2; 4-K2.4; 5-K2.9; 6-K3.6; 7-K3.8; 8-K3.12; 9-K3.16; 10-K3.22; 11-K4.11; 12-K4.13; 13-K4.15; 14-K4.16; 15-K4.17; 16-K5.6; 17-K8.7; 18-K9.2; 19-K9.8; 20-K10.7; 21-K10.8, 22-K12.5 (B) PFGE separated replicons of Rlt nodule
isolates further submitted to hybridization assays. The names of plasmids of Rlv 3841 strain, used as molecular weight markers were shown [6]. Molecular weight of Rlv 3841 plasmids is: 870, 684, 488, 353, 152, 147.5 kb. The letters on the respective bands of particular plasmids of individual strains indicates
the plasmid name, e.g., “”a”" indicates pRlea plasmid. Lanes: 1-Rlv 3841; 2-RtTA1; 3-K2.4; 4-K3.12; 5-K3.16; 6-K4.13; 7-K4.17; 8-K5.6; 9-K9.2; 10-K10.4; 11-K3.8; 12-K4.11; 13-K8.7; 14-K9.8; 15-Rlv 3841; 16-RtTA1; 17-K2.2; 18-K2.9; 19-K3.6; 20-K3.22; 21-K5.4, 22-K10.7, 23-K10.8, 25-K3.13, 26-K4.15. trifolii strains determined by PFGE Rlt strains Plasmid size (kb) pRlef pRlee pRled pRlec pRleb pRlea RtTA1 808 653 603 476* K3.8 1110 640 570 370* K3.13 1210 click here 610 590 350* 240 K3.16 915 570 520 270* 200 K3.22 1350 510 420 310* 185 K8.7 1110 710 560 330* K9.8 1250 710 580 260* K10.7 1180 710 565 430* K10.8 1120 670 600 460* K12.5 1220 670 580 395* 270 K3.6 840 620 430* K4.11 1060 610 560 350* 190 150 K4.15 770 705 640 500* K2.2 1230 650 630 440* K2.4 1250 720 570 320* K4.13 1240 650 630 420* 310 K4.16 1380 680 585 320* K4.17 1140 700 600 330* 250 K5.4 780 690 650 335* K9.2 1140 730 620 340* 250 K10.4 1130 700 570 290* K2.9 1240 810 590 375* 180 K3.12 1210 700 630 400* K5.6 1060 635 610 290* *-symbiotic plasmids Average molecular weight (m.w.) of all the plasmids in each of the 23 isolates was calculated as 2.815 Mb (ranging from 1.