Regulatory nodD1 and nodD2 genes of Rhizobium tropici strain CIAT 899 and their roles in the early stages of molecular signaling and host-legume nodulation

Table 2 Nod factor structure biosynthesized in control condition (B ⁻ medium) by wild type CIAT 899 and the nodD1 and nodD2 mutants

[M + H] ⁺ ( m / z )	B _i ions	Structure ^a	CIAT899 ^b	*nodD1* ^b	*nodD2* ^b
850	426, 629, 832	III (C_18:1)	+	+	-
1027	400, 603, 806	IV (C_16:0)	+	+	+
1041	414, 617, 820	IV (C_16:0, NMe)	-	-	+
1053	426, 629, 832	IV (C_18:1)	+	+	+
1055	428, 631, 834	IV (C_18:0)	+	-	-
1067	440, 643, 846	IV (C_18:1, NMe)	+	+	+
1216	386, 589, 792, 995	V (C_14:0, NMe)	+	-	+
1230	400, 603, 806, 1009	V (C_16:0)	+	+	+
1244	414, 617, 820, 1023	V (C_16:0, NMe)	+	+	+
1256	426, 629, 832, 1035	V (C_18:1)	+	+	+
1270	440, 643, 846, 1049	V (C_18:1, NMe)	+	+	+
1350	440, 643, 846, 1049, [M-80]^+c = 1270	V (C_18:1, NMe, S)	+	+	+
1352	442, 645, 848, 1051, [M-80]^+c = 1272	V(C_18:0, NMe, S)	-	+	-
1378	468, 671, 874, 1077, [M-80]^+c = 1298	V (C_20:1, NMe, S)	-	+	-

^aNF structures are represented following the convention (Spaink, 1992) [43] that indicates the number of GlcNAc residues in the backbone (Roman numeral), the length and degree of unsaturation of the fatty acyl chain, and the other substituents, which are listed in the order in which they appear, moving clockwise from the fatty acid. NMe, N-methyl group at glucosamine non reducing residue; S, sulfate group at reducing glucosamine residue.
^bSymbol: + = detected; − = non detected.
^cThese ions arise by loss of a neutral with mass 80 Da, corresponding to the loss of SO₃.

ISSN: 1471-2164