Table 1

List of identified xylem sap proteins from Brassica napus. Identifications of xylem sap proteins from the 2-DE gel shown in Figure 2. Sequences were determined from fragmentation spectra obtained by ESI-Q-TOF tandem MS. The resulting partial amino acid sequences were used for database searches with a BLAST algorithm optimized for short sequences. The isobaric amino acids isoleucine (I) and leucine (L), although not distinguishable by MS, are displayed as specified in the corresponding database sequences. BLAST E-values were determined using all non-redundant peptide sequences from one protein spot for another BLAST search. Bold letters in the partial sequences indicate amino acids identical to the database entry. Results of N-terminal secretion sequence predictions are indicated in the right column (Y= secretion sequence predicted, N= no secretion sequence predicted), * indicates that the observed molecular mass was lower and ** indicates that the observed mass was higher than expected.
Spot No	Similarity to	Organism	Acc. No.	Sequence	identity	E value	expected Mr	observed Mr	aS

1	Ubiquitin	Arabidopsis thaliana	At2g47110	TITLEVESSDTIDNVK	16/16 (100%)	9.00E-08	8525	12064	N
2	Ubiquitin	Arabidopsis thaliana	At2g47110	TITLEVESSDTIDNVK	16/16 (100%)	9.00E-08	8525	11944	N
3	Glycine-rich cell wall protein	Arabidopsis thaliana	At4g30450	AGSSAGSFAGSR	12/12 (100%)	0.011	9530	13863	Y
4	Pathogenesis-related protein PR1a	Brassica napus	AAB09587	SPQDYVNAHNQAR	13/13 (100%)	7.00E-39	17532	18145	Y
				LAAYAQNYADR	11/11 (100%)
				QDSPQDYVNAHNQAR	15/15 (100%)
				GPVQWDGTLAAYAQNYADR	19/19 (100%)
				AGSSADFSGVSAVNLWVNEK	20/20 (100%)
5	Glycine-rich cell wall protein	Oryza sativa	BAD62284	GGGYGEGGGYGGG	15/16 (94%)	2.00E-10	14152	17822	Y
				GGGYWGGGYGGGYGGG
6	Invertase/pectin methylesterase inhibitor	Arabidopsis thaliana	At1 g47960	GSSADTSGLALILVDK	15/16 (94%)	2.00E-32	22326	18297	Y
				GVIDAGVEAAV	10/11 (91%)
				ETPDFNLCVACPLDSDPR	15/18 (83%)
				GSSADTSGLALILVDKIK	17/18 (94%)
				ADVPEAIECCSK	10/12 (83%)
				FGEDGVIDAGVEAAV	14/15 (93%)
7	Papain-type cysteine proteinase XCP2	Arabidopsis thaliana	At4g35350	LDHGVAAVGYGSSK	14/14 (100%)	4.00E-18	39618	16,603*	Y
				ALAHQPVSVAIEASGR	16/16 (100%)
				GVDLDHGVAAVGYGSSK	16/17 (94%)
8	Papain-type cysteine proteinase XCP2	Arabidopsis thaliana	At4g35350	LDHGVAAVGYGSSK	14/14 (100%)	4.00E-18	39618	16,977*	Y
				ALAHQPVSVAIEASGR	16/16 (100%)
				GVDLDHGVAAVGYGSSK	16/17 (94%)
9	Invertase/pectin methylesterase inhibitor	Arabidopsis thaliana	At1g47960	GSSADTSGLALILVDK	15/16 (94%)	9.00E-38	22326	18297	Y
				ETPDFNLCVACPLDSDPR	15/18 (83%)
				GSSADTSGLALILVDKIK	17/18 (94%)
				ALDECASR	6/8 (75%)
				ADVPEAIECCSK	10/12 (83%)
				FGEDGVIDAGVEAAV	14/15 (93%)
10	Glycine-rich protein	Arabidopsis thaliana	At4g30460	GEGGGYGGGYGGGGD	14/15 (93%)	1.00E-04	13738	19195	Y
11	Aspartyl protease family protein	Arabidopsis thaliana	At5g07030	LPPSAIAFNPATGAGTIFDSGTVYTR	24/26 (92%)	3.00E-15	46919	21,384*	Y
				VLIDLPNSR	7/9 (77%)
12	Disease resistance response/ dirigent protein	Arabidopsis thaliana	At1g64160	VIFDDPVTLDK	8/12 (67%)	3.00E-13	20573	22711	Y
				GCLNIMGADL	9/10 (90%)
				DLSVVGGTGDFFFSR	14/15 (93%)
13	Disease resistance response/ dirigent protein	Arabidopsis thaliana	At4g23690	VIFDDPVTLDQNYLSKPVSR	17/20 (85%)	1.00E-11	21412	24544	Y
				SVVGGTGDFFMSR	13/13 (100%)
14	Endochitinase class I, putative	Arabidopsis thaliana	At2g43620	RDTIANVVTLSVFNSIFSK	12/19 (63%)	2.00E-08	30378	25856	Y
				QAFISAAAQSSDAYK	13/15 (87%)
				FNGLPLLTDPDMVSR	13/15 (87%)
15	Endochitinase class I, putative	Arabidopsis thaliana	At2g43620	RDTIANVVTLSVFNSIFSK	12/19 (63%)	2.00E-08	30378	25969	Y
				QAFISAAAQSSDAYK	13/15 (87%)
				FNGLPLLTDPDMVSR	13/15 (87%)
16	Endochitinase class I, putative	Arabidopsis thaliana	At2g43620	RDTIANVVTLSVFNSIFSK	12/19 (63%)	7.00E-13	30378	25744	Y
				QAFISAAAQSSDAYK	13/15 (87%)
				FNGLPLLTDPDMVSR	13/15 (87%)
				PVLDQGFGATTR	12/12 (100%)
17	Germin-like protein, subfamily 2	Arabidopsis thaliana	At1 g02335	YDPDALQDLCVAADK	14/15 (93%)	8.00E-07	23441	26543	Y
				KIPGLNTLSV	10/10 (100%)
				GEVFVFPR	8/8 (100%)
18	Thaumatin-like protein/ osmotin	Brassica rapa	AAN23104	RAPNTLAEYALK	12/12 (100%)	4.00E-04	incomplete	32060
19	Gamma-glutamyltranspeptidase 1	Arabidopsis thaliana	At4g39640	PPPAPANFIRPGK	13/13 (100%)	4.00E-D5	61190	26,312*	Y
				VPPPAPANFIRPGK	14/14 (100%)
				QFIVQES	7/7 (100%)
20	Endochitinase class I, putative	Arabidopsis thaliana	At2g43620	TIANVVTLSVFNSIFSK	10/17 (59%)	2.00E-20	30378	28613	Y
				QAFISAAAQSSDAYK	13/15 (87%)
				FLGLPLLTDPDFVAR	12/15 (80%)
				IQITSDNYNYGAAGK	12/17 (71%)
21	Xyloglucan:xyloglucosyl transferase	Arabidopsis thaliana	At5g57560	GQITNDGELLTLSLDK	14/16 (88%)	3.00E-36	32093	29928	Y
				LVPGNSAGTVTTLYLK	16/16 (100%)
				WFDPTWFHTYTILSDNPQR	16/19 (84%)
				IFTVDGTPIR	10/10 (100%)
				NFESVGTLFPNNKPFR	13/16 (81%)
22	Xyloglucan:xyloglucosyl transferase	Arabidopsis thaliana	At5g57560	GQITNDGELLTLSLDK	14/16 (88%)	3.00E-36	32093	30200	Y
				LVPGNSAGTVTTLYLK	16/16 (100%)
				WFDPTVVFHTYTILSDNPQR	16/19 (84%)
				IFTVDGTPIR	10/10 (100%)
				NFESVGTLFPNNKPFR	13/16 (81%)
23	Chitinase class IV, putative	Arabidopsis thaliana	At2g43570	PSFGSSISK	8/9 (89%)	2.00E-05	29775	31326	Y
				AAANSYPSFGSSISK	14/15 (93%)
				LNENLLASPEK	10/11 (91%)
				VAQDPPSAFK	7/10 (70%)
24	Peroxidase 25 precursor	Arabidopsis thaliana	At2g41480	STVESHFDSDPTISPGLLR	19/19 (100%)	4.00E-09	35886	32665	Y
				EASNLPSPLDSVAVQK	16/16 (100%)
				VALDIGSPSNFDVSFFK	15/17 (88%)
25	Legume lectin family protein	Arabidopsis thaliana	At3g16530	LAVEFDTFQNK	10/11 (91%)	4.00E-06	30509	32360	Y
				GYWVQTR	7/7 (100%)

Spot No	Similarity to	Organism	Acc. No.	Sequence	identity	E value	expected Mr	observed Mr	aS

26	Legume lectin family protein	Arabidopsis thaliana	At3g15356	GDNLFFLGDAELG	11/13(85%)	7.00E-15	29749	32819	Y
				EFDTFKNK	7/8 (88%)
				HVGININSMTSNVAEK	15/16 (94%)
				TITIAPENVK	10/10 (100%)
27	Chitinase class I	Brassica napus	CAA43708	DSFINAANTFPNFANSVTR	19/19 (100%)	5.00E-11	28733	30200	Y
				NGGNSGAVNAR	11/11 (100%)
28	Legume lectin family protein	Arabidopsis thaliana	At3g16530	LAVEFDTFQNK	9/10 (90%)	5.00E-06	30509	31763	Y
				AGYWVQTR	8/8 (100%)
29	Chitinase class I, putative	Arabidopsis thaliana	At4g01700	GFYPYEAFVEATR	13/13 (100%)	1.00E-08	31464	32819	Y
				GPIQLSWNYNYGQAGR	16/16 (100%)
30	Peroxidase, putative	Arabidopsis thaliana	At4g36430	PGTVSCAADLLTLAAR	14/16 (88%)	4.00E-05	36164	34420	Y
				QNLSVLDIVSAAK	10/13 (77%)
				GNISPLTGSSGEIR	14/14 (100%)
31	Peroxidase, putative	Arabidopsis thaliana	At4g36430	DSSVLTGGPCWVVP	13/14 (93%)	7.00E-18	36164	36508	Y
				QGLDITDLVALSGSHTIGFSR	21/21 (100%)
				NSDQVLFSS	9/9 (100%)
				GNISPLTGSSGEIR	14/14 (100%)
32	Peroxidase, putative	Arabidopsis thaliana	At1g49570	EAVVLTGGPFMAPVPLGR	16/18 (89%)	9.00E-06	38030	41164	Y
				GQPDPNLAASSDLLSK	15/16 (94%)
				GNIGVFTGSDGVIR	13/14 (93%)
33	Peroxidase ATP5a	Arabidopsis thaliana	At1g49570	EAVVLTGGPFMAPVPLGR	16/18 (89%)	7.00E-05	38030	40065	Y
				GNIGVFTGSDGVIR	13/14 (93%)
	Peroxidase 59 precursor	Arabidopsis thaliana	At5g19890	LVEAYSQSQSLFFR	13/14 (93%)	6.00E-05	35023	40065	Y
34	Serine carboxypeptidase S10 family protein	Arabidopsis thaliana	At3g17180	GFIVGNPLTDDEYDNK	16/16 (100%)	1.00E-08	54145	40,498*	Y
35	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	2.00E-09	50343	39,640	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				GVTGFEILPNGNIVLHDK	17/18 (94%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
36	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	2.00E-09	50343	36,326*	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				GVTGFEILPNGNIVLHDK	17/18 (94%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
37	Peroxidase, putative	Arabidopsis thaliana	At4g33420	PTLSAGLIR	8/9 (89%)	1.00E-17	35975	37062	Y
				NDFDNAYFNALQR	13/13 (100%)
				SGVLFSDQTLFNSPFTR	15/17 (88%)
38	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	3.00E-08	50343	37,631*	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				ILPNGNIVLHDK	12/1 (100%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
39	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	3.00E-08	50343	35,967*	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				ILPNGNIVLHDK	12/1 (100%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
40	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	3.00E-08	50343	37,824*	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				ILPNGNIVLHDK	12/1 (100%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
41	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78830	PLVYGGDSPNHDFR	11/14 (79%)	3.00E-08	50343	36,326*	Y
				VVNNDEFGDYITEYDASYR	16/19 (84%)
				ILPNGNIVLHDK	12/1 (100%)
				TGQPLVYGGDSPNHDFR	13/17 (76%)
42	Peroxidase 59 precursor	Arabidopsis thaliana	At5g19890	KNAIPNINSAR	10/11 (91%)	0.003	35023	40280	Y
				EAYSQSQSLFFR	12/12 (100%)
43	Peroxidase, putative	Arabidopsis thaliana	At4g33420	PTLAAGLIR	9/9 (100%)	1.00E-09	35975	37824	Y
				NTAEKDSPANLSLR	14/14 (100%)
				NDFDNAYFNALQR	13/13 (100%)
44	Cyclase family protein	Arabidopsis thaliana	At4g34180	DYLSFAAFDESPATHK	15/16 (94%)	1.00E-28	28384	34586	Y
				GLDYLSFAAFDESPATHK	17/18 (94%)
				EFDSSFSGFFTDGAK	13/15 (87%)
				LIGLDYLSFAAFDESPATHK	19/20 (95%)
				GRDIIPVEALK	11/11 (100%)
45	Peroxidase 21 (ATP2a)	Arabidopsis thaliana	At2g37130	DASLLLETAR	10/10 (100%)	5.00E-18	36741	35614	Y
				PTLDPDYALYLK	11/12 (92%)
				ADNGYFHEQFSR	12/12 (100%)
				LLSETNPLTGDQGEIR	16/16 (100%)
46	Peroxidase, putative	Arabidopsis thaliana	At4g33420	PTLAAGLIR	9/9 (100%)	8.00E-40	35975	38018	Y
				GFTPQDVVALSGAHTLGVAR	20/20 (100%)
				LTTPDSSFDSSFVNTLTK	13/18 (72%)
				FDNAYFNALQR	10/11 (91%)
				SGVLFSDQTLFNTPATR	17/17 (100%)
47	Peroxidase, putative	Arabidopsis thaliana	At4g33420	DNTAEKDSPANLSLR	15/15 (100%)	1.00E-25	35975	37062	Y
				GFTPQDVVALSGAHTLGVAR	20/20 (100%)
				NDFDNAYFNALQR	12/13 (92%)
				LFSDQTLFNTP	11/11 (100%)
48	Peroxidase 21 (ATP2a)	Arabidopsis thaliana	At2g37130	DASLLLETAR	10/10 (100%)	8.00E-09	36741	36691	Y
				LLSETNPLTGDQGEIR	16/16 (100%)
49	Beta-1,3-glucanase (BG3)	Arabidopsis thaliana	At3g57240	LLLDVPNPDLQR	11/12 (92%)	3.00E-1B	30712	36691	N
				YISVGNEVQPS	11/11 (100%)
				FVLPAMQNIDR	10/11 (91%)
				TYVNNLIQTVK	11/11 (100%)

Spot No	Similarity to	Organism	Acc. No.	Sequence	identity	E value	expected Mr	observed Mr	aS

50	Beta-1,3-glucanase (BG3)	Arabidopsis thaliana	At3g57240	LLLDVPNPDLQR	11/12(92%)	3.00E-18	30712	37250	N
				YISVGNEVQPS	11/11 (100%)
				FVLPAMQNIDR	10/11 (91%)
				TYVNNLIQTVK	11/11 (100%)
51	Polygalacturonase inhibitor protein 2	Brassica napus	AAM94869	NFLQFDLSR	9/9 (100%)	5.00E-05	37117	40280	Y
				LQEFDTYSYFHNK	13/13 (100%)
52	Peroxidase 59 precursor	Arabidopsis thaliana	At5g19890	PYLVQIVR	7/8 (88%)	2.00E-06	35023	41850	Y
				GFEVVDTIK	8/9 (89%)
				LVEAYSQSQSLFFR	13/14 (93%)
53	Peroxidase 59 precursor	Arabidopsis thaliana	At5g19890	PYLVQIVR	7/8 (88%)	5.00E-04	35023	43793	Y
				LVEAYSQSQSLFFR	13/14 (93%)
54	Peroxidase 59 precursor	Arabidopsis thaliana	At5g19890	PYLVQIVR	7/8 (88%)	2.00E-06	35023	43793	Y
				GFEVVDTIK	8/9 (89%)
				LVEAYSQSQSLFFR	13/14 (93%)
55	Subtilase family protein	Arabidopsis thaliana	At1g20160	AVASAYGTFPTTVIDSK	16/17 (94%)	1.00E-17	81480	56,025*	Y
				SILKPDITAPGVAILAAWTG	19/20 (95%)
				LTYQVTVSATA	10/11 (91%)
56	Subtilase family protein	Arabidopsis thaliana	At1g20160	SPVYPLIHGK	10/10 (100%)	2.00E-05	81480	56,025*	Y
				ASAYGTFPTTVIDSK	14/15 (93%)
				VSVETPAYQIQVTPEK	13/16 (63%)
				VFGALT	6/6 (100%)
57	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78850	KVPVDEQFLVVNK	10/13 (77%)	8.00E-16	49051	50573	Y
				TDYSPIEYNPDVR	13/13 (100%)
				ILENGNFVIYDSSVK	13/15 (87%)
				SVNTDGPYSLVFEDK	12/15 (80%)
				TPKPIAVREGYEFFSK	12/16 (75%)
58	Polygalacturonase/ glycoside hydrolase 28	Arabidopsis thaliana	At3g61490	DATLLAAQDLEEYPVLK	14/17 (82%)	1.00E-10	51939	56471	Y
				DEYGIAFGFPTK	10/12 (83%)
				IALGSEFSGGIEDVR	14/15 (93%)
59	Subtilase family protein	Arabidopsis thaliana	At1g20160	SPVYPLIHGK	10/10 (100%)	1.00E-10	81480	58,848*	Y
				ASAYGTFPTTVIDSK	14/15 (93%)
				SLHPTWCPSAIR	10/12 (83%)
				VSVETPAYQIQVTPEK	13/16(81%)
				LTYQVTVSAADDDV	10/14(71%)
				VFGALT	6/6 (100%)
60	Subtilase family protein	Arabidopsis thaliana	At1g20160	SPVYPLIHGK	10/10 (100%)	1.00E-10	81480	56,025*	Y
				ASAYGTFPTTVIDSK	14/15 (93%)
				SLHPTWCPSAIR	10/12 (83%)
				VSVETPAYQIQVTPEK	13/16(81%)
				LTYQVTVSAADDDV	10/14(71%)
				VFGALT	6/6 (100%)
61	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78850	KVPVDEQFLVVNK	10/13 (77%)	6.00E-11	49051	50573	Y
				TDYSPIEYNPDVR	13/13 (100%)
				ILENGNFVIYDSSVK	13/15 (87%)
				SVNTDGPYSLVFEDK	12/15 (80%)
				TPKPIAVREGYEFFSK	12/16 (75%)
62	Curculin-like (mannose-binding) lectin	Arabidopsis thaliana	At1g78850	KVPVDEQFLVVNK	10/13 (77%)	6.00E-11	49051	51999	Y
				TDYSPIEYNPDVR	13/13 (100%)
				ILENGNFVIYDSSVK	13/15 (87%)
				SVNTDGPYSLVFEDK	12/15 (80%)
				TPKPIAVREGYEFFSK	12/16 (75%)
63	Subtilase family protein	Arabidopsis thaliana	At1g20160	AVASAYGTFPTTVIDSK	16/17 (94%)	3.00E-07	81480	56,926*	Y
				TVTNVGGDRAVYK	10/13 (77%)
				VFGALT	6/6 (100%)
64	Polygalacturonase/ glycoside hydrolase 28	Arabidopsis thaliana	At3g61490	DEYGIAFGFPTK	10/12 (83%)	9.00E-08	51939	5786B	Y
				IALGSEFSGGIEDVR	14/15 (93%)
				WTLLAAQDLEEYPVLK	14/16 (88%)
65	Subtilase family protein	Arabidopsis thaliana	At1g20160	ESDVVLGGSK	9/10 (90%)	5.00E-08	81480	81188	Y
				SPVYPLIHGK	10/10 (100%)
				AVASAYGTFPTTVIDSK	16/17 (94%)
				SLHPTWCPSAIR	10/12 (83%)
				TVTNVGGDRAVYK	10/13 (77%)
				LTYQVTVSA	8/9 (89%)
66	Subtilase family protein	Arabidopsis thaliana	At1g20160	ESDVVLGGSK	9/10 (90%)	5.00E-08	81480	79849	Y
				SPVYPLIHGK	10/10 (100%)
				AVASAYGTFPTTVIDSK	16/17 (94%)
				SLHPTWCPSAIR	10/12 (83%)
				TVTNVGGDRAVYK	10/13 (77%)
				LTYQVTVSA	8/9 (89%)
67	Subtilase family protein	Arabidopsis thaliana	At1g20160	ESDVVLGGSK	9/10 (90%)	6.00E-07	81480	81188	Y
				AVASAYGTFPTTVIDSK	16/17 (94%)
				TVTNVGGDRAVYK	10/13 (77%)
				LTYQVTVSA	8/9 (89%)
				VFGALT	6/6 (100%)
68	Cucumisin-like serine protease (ARA12)	Arabidopsis thaliana	At5g67360	VEGASLLGFASGTAR	14/15 (93%)	1.00E-06	79415	78587	Y
				DGVAIGAFAAFER	12/13 (92%)
				PALAILGNGK	10/10 (100%)
				LNYPSFAVNVDGSGAYK	16/17 (94%)
				TVTFTVDSSK	10/10 (100%)
69	Germin-like protein	Arabidopsis thaliana	At3g05950	FTSGLNIAGNTIN	13/13 (100%)	7.00E-05	24736	76,260**	Y
				AFQLDVNVVR	9/10 (90%)

Kehr et al. BMC Plant Biology 2005 5:11 doi:10.1186/1471-2229-5-11