18.9 Do the lessons of animal development apply to plants? The evidence emerging from the results of comparative studies of pattern formation in a variety of animals indi-cates that many important developmental pathways are ancient inventions conserved and maintained in many, if not all, animal species. The life history, cell biology, and evolutionary origins of plants would, in contrast, argue against the appearance of these same sets of pathways in the regulation of plant development. Plants have very different organ systems from those of animals, depend on inFexible cell walls for structural rigidity, separate germ line from soma very late in development, and are very dependent on light intensity and duration to trigger various developmental events. Certainly, plants use hor-mones to regulate gene activity, to signal locally between cells by as yet unknown signals, and to create cell-fate differences by means of transcription factors. The gen-eral themes for establishing cell fates in animals are
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 01/10/2011 for the course BIOL BIOL taught by Professor Johnson during the Spring '08 term at Aberystwyth University.