HORMONAL-REGULATION OF MOSS DEVELOPMENT

The morphogenesis of mosses is regulated by the same plant hormones as in higher plants. A minimum amount of auxin and cytokinin is necessary, but the direction of morphogenesis from chloronema to caulonema needs an enhanced auxin content, from caulonema to buds a higher cytokinin level within the target cells. In both cases the higher level must act continuously and not only as a trigger. The third hormone, abscisic acid, is a mediator for the high desiccation tolerance of mosses.