Table 2.

Colonization levels of and disease severity caused by Sphingomonas sp. Fr1 mutants and controls with genes disrupted by transposon insertion and the corresponding gene in Sphingomonas sp. S17

Inoculation	Population in the phyllosphere, log(CFU/g)a			Disease indexb	Gene annotation	Identifierc	Corresponding gene in Sphingomonas sp. S17d
	Sphingomonas sp. Fr1		P. syringae DC3000, 21 dpi
	0 dpi	21 dpi
Fr1 (wild type)	8.0 ± 0.2	8.3 ± 0.4	8.1 ± 1.1	0.0
17DF5	7.6 ± 0.6	7.0 ± 0.8	8.6 ± 0.7	0.3	Cytochrome o ubiquinol oxidase subunit II	2,537	SUS17_373
17CC8	7.0 ± 0.3	6.4 ± 0.7	8.6 ± 0.9	0.4	Intergenic	1,536/1,537	—e
16BG1	7.3 ± 0.5	8.1 ± 0.9	8.3 ± 1.4	0.4	Mo cofactor biosynthesis protein C	990	SUS17_830
4JA3	5.7 ± 0.7	6.3 ± 1.0	9.1 ± 0.6	0.5	Sensor histidine kinase	1,140	SUS17_272
4CA8	7.4 ± 0.3	6.9 ± 0.6	9.5 ± 0.4	0.6	Putative membrane protein	1,490	SUS17_2491
17EH7	7.5 ± 1.0	7.8 ± 0.7	8.9 ± 0.8	0.7	Cytochrome o ubiquinol oxidase subunit IV	2,534	SUS17_370
2BB5	7.0 ± 1.2	7.5 ± 0.7	9.5 ± 0.7	0.7	GTP pyrophosphokinase (SpoT)	155	SUS17_3068
16EC12	7.7 ± 0.3	6.7 ± 0.6	9.4 ± 0.7	0.7	Putative membrane protein	1,490	SUS17_2491
5BC11	8.4 ± 0.4	8.2 ± 0.5	9.3 ± 0.5	0.7	Cytochrome o ubiquinol oxidase subunit II	2,537	SUS17_373
16AB2	6.5 ± 0.7	7.4 ± 0.7	9.1 ± 0.6	0.8	Multimodular transpeptidase-transglycosylase	869	SUS17_3528
Axenicf			9.4 ± 0.4	1.0

^aSphingomonas sp. Fr1 and P. syringae DC3000 populations in the phyllosphere at 0 and 21 days postinfection. Shown are means ± standard deviations of log-transformed CFU per gram of leaf fresh weight (n = 12).

^bDisease severity at 20 dpi. Each plant was given a rank of 1 to 5 (healthy to diseased). Shown are normalized data for the weighted arithmetic means (n = 16 to 24).

^cGene identifier according to a RAST annotation of a Sphingomonas sp. Fr1 draft genome (unpublished).

^dFrom reference 19.

^e—, no microsynteny in Sphingomonas sp. S17.

^fControl plants that were grown axenically prior to pathogen application.