Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula.

ABSTRACT: There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under st

SUBMITTER: Zhao Q 

PROVIDER: S-EPMC3746925 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature