[著者] Gaquerel E, Kotkar H, Onkokesung N, Galis I, Baldwin IT.
[論文タイトル] Silencing an N-acyltransferase-like involved in lignin biosynthesis in Nicotiana attenuata dramatically alters herbivory-induced phenolamide metabolism
[掲載論文] PLoS One 8 (5): e62336 (2013) doi: 10.1371/journal.pone.0062336
[内容紹介] Caffeic acid-derived phenolamides (PA) are newly identified defense compounds produced in tobacco plants against herbivores. Their biosynthesis shares several common precursors with the well-known lignin biosynthetic pathway in plants that is controlled by the hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) gene. As expected, experimental silencing of HCT gene not only disrupted lignin deposition in stems but also significantly affected the accumulation patterns of tobacco PAs in the leaves. However, only coumaric acid derived PAs, but not caffeic acid type PAs, accumulated in HCT-silenced plants, showing a strong metabolic separation of lignin and herbivory-related PA biosynthetic pathways. Because HCT gene was strongly induced by herbivory, our data suggest that increased lignification represents an independent and universal defense mechanism of plants against feeding insects.（文責 Group of Plant-Insect Interactions・Ivan Galis）