HYDROXYPROLINE-INDUCED CHANGES IN FORM,APICAL DEVELOPMENT,AND CELL WALL PROTEIN IN THE LIVERWORT PLAGIOCHILA ARCTICA

Hydroxy-L-proline induces phenovariation in Plagiochila arctica Bryhn & Kaal. (Plagiochilaceae) similar to that previously induced by this compound in representatives of three other families of leafy liverworts (i.e., Cephaloziaceae, Jungermanniaceae and Scapaniaceae). Because the pattern of phenovariation in P. arctica was uniform and persistent over relatively long incubation periods, adequate material for chemical analysis and reliable material for histological analysis could be obtained for the first time. These analyses revealed interesting correlations between form, cellular “behavior,” and wall chemistry in normal and phenovariant plants. The correlations interpreted in the context of available information suggest, as a working hypothesis, that hydroxyproline-proteins regulate several aspects of morphogenesis in leafy liverworts by suppressing growth and development at critical times in highly localized areas.