Plant morphogenesis: theorical bases

Comprehension of plant morphogenesis is essential for understanding organogenesis and somatic embryogenesis processes, i.e., stages of tissue and organ development of a multicellular organism, which can lead to partial or total plant regeneration. Morphogenesis comprises the integration of growth and differentiation, mediated by cell division and specialization as a result of a complex spatial and temporal hormonal control, which occurs through regulation and expression of multiple gene systems, correlative action of meristems and their derivatives and environmental variations. However, in plant tissue culture, this endogenous links are disrupted. Tissues are exposed to exogenous conditions, represented by plant growth regulators, nutrients from the culture medium and controlled conditions of temperature and light. Therefore, morphogenesis seems to be modulated by the interaction of these factors, and also by other signaling agents, that act directly or indirectly on genetic level, triggering specific processes of synthesis that interfere with various biochemical pathways. Considering that complete elucidation of all the processes involved in morphogenesis has not been established yet, is essential to do a comprehensive study, particularly of the main factors implicated in these processes. In this context, this review aims to discuss, in general, the factors involved in the acquisition of competence, determination and cellular differentiation of morphogenesis processes, which may contribute to a better understanding and provide a basis for new research.