Arabidopsis, a useful weed

Abstract

Plants are unique in many aspects of development, cell biology, biochemistry, and physiological response. Plant cells do not migrate during morphogenesis, and totipotency of cells from many organs shows that plant development does not require maternal storage of positional information. Plant cell division is unlike that in other eukaryotes; plant cells are connected to their neighbors by unique structures (plasmodesmata) and live encased in a singular type of matrix (the cell wall). Plant biochemistry involves not only the metabolic processes familiar in animals but also several types of photosynthesis, as well as synthesis of an extraordinary range of plant-specific chemicals, many used in defense against herbivores and bacterial and fungal plant pathogens. In response to their environment, plants utilize unique pathways of light and gravity detection; in both environmental response and development they use growth substances, or hormones, quite unlike those of organisms in other kingdoms. Not only are these hormones chemically different from those in animals, but their use does not involve specific endocrine organs. Many of the most perplexing aspects of plant physiology, development, and biochemistry are now coming to be studied by the methods of classical and molecular genetics.