Table 2. Growth promotion of seed plants by added Methylobacterium species.

			Strain name of isolated Methylobacterium species
		Control (water)	21B	21C	22A
Arabidopsis thaliana (n = 30)	Root length (cm)	1.1±1.3	2.2±1.6*	1.8±1.6	2.1±1.8*
	Fresh mass (mg)	18±9.0	23±13.5	22±11.5	29±13.6**
Nicotiana tabacum (n = 30)	Shoot length (cm)	0.52±0.10	0.55±0.10	0.53±0.05	0.78±0.16**
	Root length (cm)	1.0±0.42	0.90±0.24	1.3±0.28**	1.1±0.34
	Fresh mass (mg)	41±20.3	58±17.6**	75±11.1**	70±19.5**
Nicotiana benthamiana (n = 30)	Shoot length (cm)	0.51±0.36	0.42±0.11	0.53±0.10	0.53±0.13
	Root length (cm)	1.2±0.78	1.1±0.45	1.4±0.32	1.1±0.30
	Fresh mass (mg)	44±28.0	22±8.2**	26±8.4**	66±12.0**
Oryza sativa (n = 45)	Shoot length (cm)	4.1±1.01	nt	3.7±0.98	3.9±0.75
	Root length (cm)	10±3.1	nt	8.8±3.2	9.4±3.4
	Fresh mass (mg)	61±12.4	nt	64±12.6	67±11.5*
Glycine max (n = 21)	Shoot length (cm)	7.7±1.9	8.3±0.9	8.1±1.6	8.1±2.1
	Root length (cm)	9.8±3.3	11±1.4	12±3.4	7.1±3.1*
	Lateral root number	26±9.9	37±6.8**	39±12.3**	28±10.3
	Fresh mass (g)	1.4±1.25	1.5±0.18*	1.6±0.31*	1.4±0.24

Data presented as mean ± SD. Fresh mass indicates that of entire plants.

nt: not tested.

^*, p<0.05 and.

^**, p<0.01 (Student's T-test).