Fig. 2.

Electron microscope observation for effects of SA on ultrastructure in chilling-stressed banana seedling leaves. (a) Mesophyll cells of banana seedlings growing at normal growth conditions (30/22 °C); (b) Mesophyll cells of banana seedlings treated by 0.5 mmol/L SA at 30/22 °C for 1 d; (c) Mesophyll cells of banana seedlings suffered from 7 °C stress for 3 d; (d) Mesophyll cells of SA-pretreated banana seedlings suffered from 7 °C stress for 3 d; (e) Chloroplast of mesophyll cells of banana seedlings growing at 30/22 °C; (f) Chloroplast of mesophyll cells of banana seedlings treated by SA at 30/22 °C for 1 d; (g) Chloroplast of mesophyll cells of banana seedlings suffered from 7 °C stress for 3 d; (h) Chloroplast of mesophyll cells of SA-pretreated banana seedlings suffered from 7 °C stress for 3 d; (i) Thylakoid of mesophyll cells of banana seedlings growing at 30/22 °C; (j) Thylakoid of mesophyll cells of banana seedlings treated by SA at 30/22 °C for 1 d; (k) Thylakoid of mesophyll cells of banana seedlings suffered from 7 °C stress for 3 d; (l) Thylakoid of mesophyll cells of SA-pretreated banana seedlings suffered from 7 °C stress for 3 d; (m) Mitochondria of mesophyll cells of banana seedlings growing at 30/22 °C; (n) Mitochondria of mesophyll cells of banana seedlings treated by SA at 30/22 °C for 1 d; (o) Mitochondria of mesophyll cells of banana seedlings suffered from 7 °C stress for 3 d; (p) Mitochondria of mesophyll cells of SA-pretreated banana seedlings suffered from 7 °C stress for 3 d

C: Cell membrane; CH: Chloroplast; CM: Chloroplast membrane; CR: Crevice; GT: Grana thylakoid; L: Lipid droplet; M: Mitochondria; MC: Mitochondria cristae; MM: Mitochondria membrane; N: Nucleus; S: Starch; ST: Stromal thylakoid; V: Vacuole; VE: Vesicle. White lines of black panes express bars of magnification