Pollen grain development is compromised in Arabidopsis agp6 agp11 null mutants

• Type: Article in International Scientific Journal
• Date: 2009

Authors

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

Journal

Title: Journal of Experimental Botany

Vol. 60 No. 4

Pages: 3133-3142

ISSN: 0022-0957

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 98 Citations

Scopus - 102 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10