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).