Fig. 4.

Expression profiles of GhMKK5 in different tissues and under different stress conditions. (A) Tissue-specific expression of GhMKK5 analysed by northern blot using the total RNA extracted from roots, stems, and cotyledon leaves of 7-day-old cotton seedlings. For stress treatments, 7-day-old cotton seedlings obtained from hydroponic culture were treated with low temperature (4 °C) (B), wounding (C), 200 mM NaCl (D), 10 μM MV (E), F. oxysporum f. sp. vasinfectum (F), 10 mM SA (G), 100 μM H₂O₂ (H), 100 μM MeJA (I), 100 μM ABA (J), and 5 mM ET released from ethephon (K). Total RNA was isolated at the indicated times after the treatments and was subjected to northern blot analysis using α-³²P-labelled GhMKK5 cDNA fragments as a probe. The ethidium bromide (EB)-stained rRNA is included as a loading control. This experiment was repeated at least twice.