RESUMO
The PEN1-SNAP33-VAMP721/722 exocytic pathway is a conserved immunity-associated secretory pathway between monocotyledonous barley and dicotyledonous Arabidopsis plants. In Arabidopsis, this secretory pathway plays an additional role in plant growth and development. However, how this pathway can be manipulated to engage in both growth/development and immunity remains to be answered. To understand its regulation, we recently analyzed the expression of VAMP721/722 genes whose products drive secretory vesicles to the target plasma membrane. By investigating their transcript and protein levels, we found that plants distinctly control the activity of this secretory pathway during biotic or abiotic stress responses. Since stress responses are in general accompanied by growth inhibition in plants and since plants in nature are simultaneously threatened by a number of environmental stresses, understanding of this growth/immunity-related secretory pathway would help to generate more efficiently growth/immunity-balancing plants.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Modelos Biológicos , Proteínas R-SNARE/metabolismo , Estresse Fisiológico , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Desenvolvimento Vegetal/genética , Imunidade Vegetal/genética , Proteínas R-SNARE/genética , Estresse Fisiológico/genéticaRESUMO
Effective recognition of pathogens and rapid execution of immune responses are essential for the survival of living organisms. Cell-autonomous immune responses of animal and plant cells rely on pattern recognition receptors that can distinguish self from non-self structures and that are able to activate a molecular execution machinery that ultimately terminates most pathogen attacks. Reminiscent of the situation in mammalian T cells, accumulating evidence points to a key role of vesicle trafficking and exocytosis in plant innate immunity. In this context, our recent finding that ternary soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) complexes comprising PEN1, SNAP33 and VAMP721/722 function at pathogen entry sites is instrumental in understanding the execution of plant immune responses at the cell periphery. Our study further revealed unexpected overlapping functions of the same SNARE complexes in disease resistance and development. Here, we discuss the potential identity of cargo delivered through the PEN1-SNAP33-VAMP721/722-dependent secretory pathway and the necessity for a tight regulation of SNARE complex formation to avoid unintentional release of toxic load.
