Pollen grain development is compromised in Arabidopsis agp6 agp11 null mutants

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Silvia Coimbra (Autor) FCUP; Mario Costa (Autor) Outra; Brian Jones (Autor) Outra; Marta Adelina Mendes (Autor) Outra; Luis Gustavo Pereira (Autor) FCUP

Revista

Título: Journal of Experimental Botany

Vol. 60 Nº 4

Páginas: 3133-3142

ISSN: 0022-0957

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 98 Citações

Scopus - 102 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Ciências biológicas

Outras Informações

ID Authenticus: P-003-HW0

DOI: 10.1093/jxb/erp148

Abstract (EN): Arabinogalactan proteins (AGPs) are structurally complex plasma membrane and cell wall proteoglycans that are implicated in diverse developmental processes, including plant sexual reproduction. Male gametogenesis (pollen grain development) is fundamental to plant sexual reproduction. The role of two abundant, pollen-specific AGPs, AGP6, and AGP11, have been investigated here. The pollen specificity of these proteoglycans suggested that they are integral to pollen biogenesis and their strong sequence homology indicated a potential for overlapping function. Indeed, single gene transposon insertion knockouts for both AGPs showed no discernible phenotype. However, in plants homozygous for one of the insertions and heterozygous for the other, in homozygous double mutants, and in RNAi and amiRNA transgenic plants that were down-regulated for both genes, many pollen grains failed to develop normally, leading to their collapse. The microscopic observations of these aborted pollen grains showed a condensed cytoplasm, membrane blebbing and the presence of small lytic vacuoles. Later in development, the generative cells that arise from mitotic divisions were not seen to go into the second mitosis. Anther wall development, the establishment of the endothecium thickenings, the opening of the stomium, and the deposition of the pollen coat were all normal in the knockout and knockdown lines. Our data provide strong evidence that these two proteoglycans have overlapping and important functions in gametophytic pollen grain development.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10