Table 5.

Effects of apigenin, nodD1, andnodSU on Nod factor production and nodulation of L. leucocephala by strains NGR234 and USDA257

StrainaNod factor productionbNodulation of L. leucocephala
− Apigenin+ Apigenin
NGR2340.4 ± 0.261.8 ± 9.7Nod+Fix+
NGRΔnodD10.4 ± 0.30.3 ± 0.2Nod
NGRΔnodSU0.3 ± 0.35.7 ± 2.5Nod
USDA2570.2 ± 0.21.5 ± 1.1Nod
USDA257(nodSU)0.1 ± 0.138.3 ± 9.8Nod+Fix+
  • a NGRΔnodD1,nodD1 mutant of Rhizobium sp. strain NGR234; NGRΔnodSU, nodSU mutant of strain NGR234; USDA257 (nodSU), R. fredii USDA257 transconjugant containing the functional nodSU genes of NGR234.

  • b Nod factors were quantified using the tomato cell suspension assay (259). The results are expressed in nanomoles per milliliter of culture corrected to an absorbance at 700 nm of 1 and were taken from references 144, 158, and214.