GhLac1 transgenic lines show an altered phenylpropanoid pathway and phytohormone homeostasis. A, Lignin content in the roots and young leaves. Values are the means ± sd; n = 6. B, Total flavonoid content and gossypol equivalent content in the roots and young leaves. Values are the means ± sd; n = 6. C, JA and JA-Ile contents in the roots between Mock and V. dahliae-inoculated plants. Roots were collected after inoculation with V. dahliae spores or sterile distilled water for 6 h. Values are the means ± sd; n = 9. D, JA and JA-Ile contents in the leaves between Mock, cotton bollworm-, and cotton aphid-infected plants. Statistical analyses were performed using Student’s t test. *, P < 0.05; **, P < 0.01. Values are the means ± sd; n = 9. All of the experiments were repeated at least three times with similar results.