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 3 Nod factor structure biosynthesized in the presence of apigenin (3.7 μM) by wild type CIAT899 and the nodD1 and nodD2 mutants

[M + H] ⁺ ( m / z )	B _i ions	Structure ^a	CIAT899 ^b	*nodD1* ^b	*nodD2* ^b
810	386, 589	III (C_14:0, NMe)	-	-	+
824	400, 603	III (C_16:0)	-	+	+
838	414, 617	III (C_16:0, NMe)	+	+	+
850	426, 629	III (C_18:1)	+	+	+
852	428, 631	III (C_18:0)	+	-	-
864	440, 643	III (C_18:1, NMe)	+	-	+
999	372, 575, 778	IV (C_14:0)	+	+	-
1011	384, 597, 790	IV (C_14:1, NMe)	+	-	-
1013	386, 589, 792	IV (C_14:0, NMe)	+	+	+
1025	398, 601, 804	IV (C_16:1)	+	+	+
1027	400, 603, 806	IV (C_16:0)	+	+	+
1039	412, 615, 818	IV (C_16:1, NMe)	+	+	+
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)	+	-	+
1069	442, 645, 848	IV (C_18:0, NMe)	+	-	+
1081	454, 657, 860	IV (C_20:1)	+	-	-
1147	440, 643, 846	IV (C_18:1, NMe, S)	-	-	+
1202	372, 575, 778, 981	V (C_14:0)	+	+	-
1214	426, 629, 790, 832, 993^d	V (C_18:1, dNAc)	+	-	-
1216	386, 589, 792, 995	V (C_14:0, NMe)	+	+	+
1228	440, 643, 846, 1007^e	V (C_18:1, NMe, dNAc)	+	-	-
1230	400, 603, 806, 1009	V (C_16:0)	+	+	-
1231	440, 643, 846, 1049	IV Hex-ol (C_18:1, NMe)	-	-	+
1242	412, 615, 818, 1021	V (C_16:1, NMe)	+	+	+
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)	+	+	+
1272	442, 645, 848, 1051	V (C_18:0, NMe)	+	-	+
1284	454, 657, 860, 1063	V (C_20:1)	-	-	+
1324	414, 617, 820, 1023	V (C_16:0, NMe, S)	+	-	+
1336	426, 629, 832, 1035	V (C_18:1, S)	+	+	-
1350	440, 643, 846, 1049, [M-80]^+c = 1270	V (C_18:1, 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. Hex-ol, hexytol (reduced terminal hexose); 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.
^dMixture of two Nod Factors, deacetylated at glucosamine residues numbers 2 and 3, respectively.
^eNod Factor deacetylated at glucosamine residue number 2.

ISSN: 1471-2164