BOTANICA	Comunicación intercelular a distancia a través del floema en plantas
	© María de Jesús Elisa León Ramírez, Beatriz Xoconostle Cázares, Roberto Ruiz Medrano , 2004   rmedrano@enigma.red.cinvestav.mx

[RESUMEN]ABSTRACT

In many cases the observed response to different environmental stimuli in plants occurs in tissues additional to those that perceive the stimulus, such as the response to pathogen attack and flowering. In the first case, a defense response is established in non-infected tissues, while in the second case the shoot apex becomes a reproductive structure, in both cases in response to signals produced in leaves that perceived the original stimulus and are transported to other tissues via the phloem. These are the conduits through which nutrients produced by photosynthesis are distributed to the rest of the plant. Classical plant hormones and other small molecules have been proposed as signals, although recent evidence suggests that proteins and nucleic acids could also be signals, taking into account viral movement within the phloem and the propagation of postranscriptional gene silencing.