TABLE 4.

Dependence of MobA-mediated transfer on VirE2^a

Strain ratio	Transfer efficiency				VirE2+/VirE2− ratio		Transfer efficiency				VirE2+/VirE2− ratio
	Dilution strain: VirE2−		Dilution strain: VirE2+				Dilution strain: VirE2−		Dilution strain: VirE2−
	Expt 1	Expt 2	Expt 1	Expt 2	Expt 1	Expt 2	Expt 3	Expt 4	Expt 3	Expt 4	Expt 3	Expt 4
1	0.7	1.2	7.6	—b	10.8	NAc	—	—	—	—	NA	NA
1/2	0.3	0.49	3.4	2.8	11.3	5.7	—	—	—	—	NA	NA
1/10	—	0.09	—	0.7	NA	7.8	1.4	0.2	3.9	0.6	2.8	3
1/50	0.01	—	0.15	0.1	15	NA	0.3	0.05	0.88	0.17	2.9	3.4
1/100	—	—	0.08	—	NA	NA	—	—	0.48	0.08	NA	NA

^aFour independent experiments were performed, in which either an Agrobacterium strain (experiments 1 and 2) or a plant transgenic for VirE2 (experiments 3 and 4) was used as a donor of VirE2 protein. Transfer efficiencies were measured in GUS spots and seedlings. 1/2, 1/10, 1/50, and 1/100 are the ATvirΔD2(pMob/pTd73)/dilution strain ratios (above the columns of data used to make the dilutions for inoculation of the seedlings. For the control experiments without an additional VirE2 source (first two columns of data for experiments 1 and 2 and experiments 3 and 4), the strain with virE2 deleted (ATvirΔE2), represented by VirE2⁻, was used as the diluting Agrobacterium strain. For complementation experiments 1 and 2 (middle two columns), strain ATvirΔD2, represented by VirE2⁺, was used as the VirE2 source for the dilutions. In experiments 3 and 4, in which transgenic plants were used as the VirE2 source, the dilutions were performed with strain ATvirΔE2, in which virE2 is deleted. Efficiency of VirE2 complementation is presented (in the rightmost columns of paired data) as the ratio of transfer efficiencies obtained in the presence/absence of an additional VirE2 source (VirE2⁺/VirE2⁻). 

^b—, not tested. 

^cNA, not applicable.