Legume Root Transformation and Nodulation

The plant materials were M. truncatula A17, soybean (G. max cv. Williams 82) and L. japonicus Gifu. Roots of these legumes were transformed using Agrobacterium rhizogenes strain ARqua-1 or K599 carrying specific vectors^{28 (link),29 (link)}. Nodules were induced on soybean by B. japonicum CB1809 when the NCR169 promoter activity was investigated and by B. japonicum USDA110 wild-type, its ΔbclA mutant, when the effects of NCR169 on bacteroids were tested. L. japonicus was inoculated with M. loti R7A and M. truncatula by S. medicae WSM419. Plants for nodulation were grown in vermiculite and fertilized once per week with 1 g l⁻¹ of Plant-Prod fertilizer (0–15–40, N–P–K; Brampton) in a growth chamber programmed for 16 h light and 8 h dark, at 28 °C/22 °C day/night for soybean and at 22 °C/20 °C day/night for M. truncatula and L. japonicus.