Figure 6.

Silencing of CsLAC18 by VIGS causes enhanced cold sensitivity in Poncirus trifoliata. (a–e,g–j) Phenotype (a), EL (b), MDA content (c), chlorophyll fluorescence imaging (d), Fv/Fm ratio (e), H₂O₂ level (g), CAT activity (h), SOD activity (i), and POD activity (j) of control plants (TRV) and VIGS plants (TRV-CsLAC18) before and after the cold treatment (12 h at −4 °C). (f) DAB and NBT staining of the leaves of trifoliate orange under cold stress. Asterisks indicate significant difference between the WT and the VIGS lines (* p < 0.05, ** p < 0.01, *** p < 0.001). Scale bars = 1 cm (a,d,f).