PPOX and infection: After inoculation with S. scitamineum, the expression level of CCR in YC05–179 and ROC22 was upregulated (Fig. 6B), which coincided with the increase in PPO activity at 2 and 5 d after inoculation (Fig. 2), suggesting that high expression of CCR transcript and PPO activity may promote the synthesis and accumulation of lignin to actively respond to S. scitamineum infection.