Fig 2. M. truncatula (cv. A17) defense triggered by aphids’ feeding or aphid saliva.
(a-e) Relative expression levels of M. truncatula JA and SA pathway genes induced by aphids. Serratia -: Serratia -free aphids and Serratia +: Serratia -infected aphid. (a)PAL , phenylalanine ammonia lyase; (b) NPR1 , nonexpresser of PR genes 1; (c) PR1 , pathogenesis-related protein 1; (d)LOX2 , lipoxygenase 2; (e) AOS2 , allene oxide synthase 2. (n=6). (f) H2O2 concentration induced by 10 Serratia -infected and Serratia -free aphids, respectively for 6 h (n=6). (g) Subcellular localization of fluorescent probes, DCFH-DA, in leaves of M. truncatula infiltrate bySerratia -free (the middle panel) and Serratia -infected aphid saliva (the lower panel). Control (the upper panel): 15% sucrose solution treatment. Bars = 100 μm. (h) Normalized fluorescence (ΔF/F0) of Ca2+ signal measurements every 3 s in N. benthamiana detached leaves infiltrated bySerratia -: Serratia -free, and Serratia +:Serratia -infected aphids saliva. Control: 15% sucrose solution treatment. ΔF, the difference between measured fluorescence and the fluorescence of the very first picture (F0) (n=15). Yellow shading indicates significant difference between Serratia - and Serratia + treatment (P < 0.05). (i) Representative fluorescence microscope images showing fluorescence of Ca2+ signal in N. benthamiana leaves infiltrated by Serratia -free (the middle panel) andSerratia -infected aphid saliva (the lower panel). Control (the upper panel): 15% sucrose solution treatment. Bars = 100 μm. The data shown are mean ± standard error (SEM). * above the bars indicate significant differences among different treatments at P < 0.05 (t-test, *P < 0.05, **P < 0.01, ***P < 0.001).