Self-incompatibility is a widespread mechanism in flowering plants that prevents inbreeding and promotes outcrossing. The self-incompatibility response is genetically controlled by one or more multi-allelic loci, and relies on a series of complex cellular interactions between the self-incompatible pollen and pistil. Although self-incompatibility functions ultimately to prevent self-fertilization, flowering plants have evolved several unique mechanisms for rejecting the self-incompatible pollen. The self-incompatibility system in the Solanaceae makes use of a multi-allelic RNase in the pistil to block incompatible pollen tube growth. In contrast, the Papaveraceae system appears to have complex cellular responses such as calcium fluxes, actin rearrangements, and programmed cell death occurring in the incompatible pollen tube. Finally, the Brassicaceae system has a receptor kinase signalling pathway activated in the pistil leading to pollen rejection. This review highlights the recent advances made towards understanding the cellular mechanisms involved in these self-incompatibility systems and discusses the striking differences between these systems.

RESUMO:Objetivou-se com este trabalho avaliar os efeitos da aplicação de diferentes fontes e doses de nitrogênio no crescimento da cana-de-açúcar, no ciclo de cana-planta. O experimento foi conduzido em condições de campo, em área da Fazenda Rio Paraiso II pertencente à Usina Raízen, no município de Jataí, GO. O solo coletado foi classificado como Latossolo Vermelho distrófico, muito argiloso, fase cerrado. PALAVRAS-CHAVE:Saccharum spp., ureia, nitrato de amônio, biometria. GROWTH OF SUGARCANE UNDER DIFFERENT SOURCES AND DOSES OF NITROGEN IN DYSTROPHIC RED LATOSOLABSTRACT: The aim of this work was to evaluate the effects of the application of different sources and doses of nitrogen in the growth of sugarcane in cane plant. We conducted the experiment under field conditions, in the area of Rio Paraiso II farm belonging to the Raízen 1 Mestrando em Ciências Agrárias -Agronomia, Instituto Federal Goiano -Campus Rio Verde, Rodovia Sul Goiana, Km 01, CEP: 75.901-170, Rio Verde -GO,