Analysis of the lignin contents and related enzymes activities in seed coat between black-seeded and yellow-seeded rapes (Brassica napus)

摘要

A pair of near isogenic yellow/black seeded rape (Brassica napus) were used as experimental materials to study the changes of lignin contents and enzymes activities of 4-coumarate: Co A ligase (4CL), Cinnamyl alcohol dehydrogenase (CAD) and ferulate 5-hydroxylase (F5H) in seed coat during seed development. The results showed that the changes of lignin contents and enzyme activites of 4CL, CAD and F5H in seed coat had significant differences between black- and yellow-seeded rapes, and also between different development stages. Correlation analysis demonstrated that the lignin contents were positively related to the activities of all three enzymes investigated in the study, and the interactions between them in the seed coat of the two lines. For yellow-seeded rape, except the correlation coefficient of lignin content and 4CL was not significant, the other correlation coefficients were significant or even highly positively significant. For the black-seeded rape, only the lignin content was highly positively related to the activity of F5H, the other correlation coefficients were not significant. It is suggested that 4CL, CAD and F5H regulate the biosynthesis of lignin in the seed coat of the rapes, leading to the lignin contents in the seed coat of the yellow-seeded rape much lower than that of the black-seeded line, and affecting the thickness of seed coat in rapes.