ABNORMAL LIGNIN IN A LOBLOLLY-PINE MUTANT

Novel lignin is formed in a mutant loblolly pine (Pinus taeda L.) seve rely depleted in cinnamyl alcohol dehydrogenase (E.C. 1.1.1.195), whic h converts coniferaldehyde to coniferyl alcohol, the primary lignin pr ecursor in pines. Dihydrocbniferyl alcohol, a monomer not normally ass ociated with the lignin biosynthetic pathway, is the major component o f the mutant's lignin, accounting for similar to 30 percent (versus si milar to 3 percent in normal pine) of the units. The level of aldehyde s, including new 2-methoxybenzaldehydes, is also increased. The mutant pines grew normally indicating that, even within a species, extensive variations in lignin composition need not disrupt the essential funct ions of lignin.