Down-regulation of hydroxycinnamoyl CoA: Shikimate hydroxycinnamoyl transferase in transgenic alfalfa affects lignification, development and forage quality

Transgenic alfalfa (Medicago sativa L.) plants were generated in which the levels of the enzyme hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) were reduced through antisense HCT expression. These plants had strongly reduced lignin content and striking changes in lignin monomer composition. Analysis of forage quality parameter showed strong reductions of neutral- and acid-detergent fiber in the down-regulated lines, in parallel with large increases (up to 20%) in dry matter forage digestibility.