These results imply that F5H expression is essential for S lignin synthesis during stem development.
For example, wounding induces the genes involved in lignin biosynthesis, such as PAL (phenylalanine ammonia-lyase), C4H (cinnamate 4hydroxylase), F5H, CAD (cinnamyl alcohol dehydrogenase), CCR (cinnamoyl-CoA reductase), and 4CL (4-coumarate-CoA ligase), which caused accumulation of lignin compounds surrounding the wounding sites [23, 52, 53].
As a key enzyme in lignin synthesis, F5H induction by cold might lead to lignification in kenaf stem tissues.
When detached leaves were treated with ABA, F5H was found to be induced in Camptotheca acuminata , suggesting that F5H might belong to the ABA-dependent pathway.
Inour study, we found the upregulation of F5H by MeJA in kenaf.
In summary, a full length of the gene F5H encoding ferulate 5-hydroxylase was cloned from kenaf (Hibiscus cannabinus L.).