Fig. 7

Incompatible rhizobia induce shoot to root transport of G3P. a, b Average number of nodules produced by U122 or U257 on a wild-type, b control VIGS vector inoculated (V) or G3Pdh knockdown (Sil_G3Pdh) Rj2 rfg1 plants, that were leaf-infiltrated with MgCl₂ or G3P 24 h after rhizobia inoculation. Black circles on x axis indicates absence of nodules. c Quantification of radioactivity (left panel) and percentage ¹⁴C-G3P transported (right panel) to stem and roots of Rj2 rfg1 plants that were root-inoculated with buffer (MgCl₂), U122 (incompatible), or U257 (compatible) followed by leaf infiltration with ¹⁴C-G3P. ¹⁴C levels were measured 48 h later. d Autoradiograph of Rj2 rfg1 seedlings that were root-inoculated with MgCl₂, U122 or U257 followed by ¹⁴C-G3P infiltration in leaves. Images were obtained 24 h post ¹⁴C-G3P infiltration. e Autoradiograph of thin-layer chromatogram (TLC) of leaf and root extracts prepared from plants that were root-inoculated with MgCl₂, U122 or U257 followed by leaf infiltration with ¹⁴C-G3P. ¹⁴C-G3P and ¹⁴C-glycerol were loaded as controls. The extracts were prepared 48 h post rhizobia inoculation and chromatographed on a cellulose plate. Vertical arrow indicates direction of run. Arrowhead indicates glycerol. f Pst Vir counts in leaves of Arabidopsis thaliana (Col-0) plants that were pre-infiltrated with TLC separated root extracts from MgCl₂ or U122-inoculated Rj2 rfg1 soybean plants as in (e). Root extracts from Rj2 rfg1 plants inoculated with MgCl₂ or U122 (root) were separated on TLC. TLC extracts were infiltrated into A. thaliana plants followed by Pst Vir inoculation on systemic leaves, 48 h later. LOG₁₀ values of colony forming units (CFU) ^ cm²-1 leaf area are presented. Error bars indicate standard deviation (n = 4). Asterisks denote data significantly different from corresponding mock, Student’s t-test, P < 0.005. Results are representative of two-four independent experiments.