Early germination of Arabidopsis pollen in a double null mutant for the arabinogalactan protein genes AGP6 and AGP11

Coimbra, Sı́lvia; Costa, Mário; Mendes, Marta Adelina; Pereira, Ana Marta; Pinto, João Correia; Pereira, Luís Gustavo

doi:10.1007/s00497-010-0136-x

Cited by 57 publications

(62 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the 16 Arabidopsis GPI-AGPs, there are some robust groupings (greater than 70% bootstrap values), but only between pairs of sequences. For example, the pollen-specific AtAGP6 and AtAGP11 (Pereira et al, 2006;Coimbra et al, 2009Coimbra et al, , 2010 A, Protein disorder (PONDR) plots (see "Materials and Methods") for AtAGP6 (At5g14380; left), AtEXT3 (At1g21310; middle), and prolyl-4-hydroxylase (AtP4H1; At2g43080; right) using VL-XT (red), VL3 (green), and VSL2 (blue). PONDR prediction scores above the threshold line (0.5) predict disorder; below the line, they predict order.…”

Section: Resultsmentioning

confidence: 99%

Pipeline to Identify Hydroxyproline-Rich Glycoproteins

et al. 2017

View full text Add to dashboard Cite

Intrinsically disordered proteins (IDPs) are functional proteins that lack a well-defined three-dimensional structure. The study of IDPs is a rapidly growing area as the crucial biological functions of more of these proteins are uncovered. In plants, IDPs are implicated in plant stress responses, signaling, and regulatory processes. A superfamily of cell wall proteins, the hydroxyprolinerich glycoproteins (HRGPs), have characteristic features of IDPs. Their protein backbones are rich in the disordering amino acid proline, they contain repeated sequence motifs and extensive posttranslational modifications (glycosylation), and they have been implicated in many biological functions. HRGPs are evolutionarily ancient, having been isolated from the protein-rich walls of chlorophyte algae to the cellulose-rich walls of embryophytes. Examination of HRGPs in a range of plant species should provide valuable insights into how they have evolved. Commonly divided into the arabinogalactan proteins, extensins, and proline-rich proteins, in reality, a continuum of structures exists within this diverse and heterogenous superfamily. An inability to accurately classify HRGPs leads to inconsistent gene ontologies limiting the identification of HRGP classes in existing and emerging omics data sets. We present a novel and robust motif and amino acid bias (MAAB) bioinformatics pipeline to classify HRGPs into 23 descriptive subclasses. Validation of MAAB was achieved using available genomic resources and then applied to the 1000 Plants transcriptome project (www.onekp.com) data set. Significant improvement in the detection of HRGPs using multiple-kmer transcriptome assembly methodology was observed. The MAAB pipeline is readily adaptable and can be modified to optimize the recovery of IDPs from other organisms.

show abstract

Section: Resultsmentioning

confidence: 99%

Pipeline to Identify Hydroxyproline-Rich Glycoproteins

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In other studies aiming at a more inclusive phenotypic characterization of the agp6 agp11 double null mutants, it was detected that a number of pollen grains germinated precociously inside the anthers and this phenomenon was dependent upon the relative humidity of the growth chamber (Coimbra et al, 2010). Pollen germination inside anthers was not observed in single agp6 or agp11 mutants, and therefore those observations indicated that the double mutation was needed to induce the precocious germination character.…”

Section: Reverse Geneticsmentioning

confidence: 95%

“…We have further characterized the anthers and pollen of agp6 agp11 and concluded that both AGPs, AGP6 and AGP11, are necessary for the proper pollen tube growth as well as for preventing untimely pollen grain germination (Coimbra et al, 2010). Further details on the biology of pollen-specific AGPs are expected to emerge from a microarray experiment performed on RNA isolated from pollen tubes of agp6 agp11 mutant, and which is currently under analysis.…”

Section: Conclusion and Future Perspectivesmentioning

confidence: 96%

See 1 more Smart Citation

Arabinogalactan Proteins in Arabidopsis thaliana Pollen Development

Coimbra¹,

Pereira²

2012

Transgenic Plants - Advances and Limitations

View full text Add to dashboard Cite

“…A few AGPs, for example, AtAGP6 and AtAGP11, have been implicated in pollen development (Coimbra et al, 2009). A double null agp6 agp11 mutant has collapsed pollen grains, reduced (and precocious) pollen grain germination and tube elongation, and displays shorter fruits with less seeds; these phenotypes are due to pollen abortion (Coimbra et al, 2009(Coimbra et al, , 2010.BLAST searches of the Arabidopsis genome using mammalian b-(1,3)-GalT sequences as queries identified 20 genes of the CAZy Glycosyltransferase (GT) 31 family (www.cazy.org/) as potentially being involved in the synthesis of the type II AG backbone of AGPs (Qu et al, 2008). Based on phylogenetic analysis, the Arabidopsis GT31 family GalTs were grouped into four clades [clades 1 (VIII and IX), 7 (V and VI), 10 (I to IV), and 11 (VII); Qu et al, 2008;Egelund et al, 2011].…”

mentioning

confidence: 99%

KNS4/UPEX1: A Type II Arabinogalactan β-(1,3)-Galactosyltransferase Required for Pollen Exine Development

et al. 2016

View full text Add to dashboard Cite

Pollen exine is essential for protection from the environment of the male gametes of seed-producing plants, but its assembly and composition remain poorly understood. We previously characterized Arabidopsis (Arabidopsis thaliana) mutants with abnormal pollen exine structure and morphology that we named kaonashi (kns). Here we describe the identification of the causal gene of kns4 that was found to be a member of the CAZy glycosyltransferase 31 gene family, identical to UNEVEN PATTERN OF EXINE1, and the biochemical characterization of the encoded protein. The characteristic exine phenotype in the kns4 mutant is related to an abnormality of the primexine matrix laid on the surface of developing microspores. Using light microscopy with a combination of type II arabinogalactan (AG) antibodies and staining with the arabinogalactan-protein (AGP)-specific b-Glc Yariv reagent, we show that the levels of AGPs in the kns4 microspore primexine are considerably diminished, and their location differs from that of wild type, as does the distribution of pectin labeling. Furthermore, kns4 mutants exhibit reduced fertility as indicated by shorter fruit lengths and lower seed set compared to the wild type, confirming that KNS4 is critical for pollen viability and development. KNS4 was heterologously expressed in Nicotiana benthamiana, and was shown to possess b-(1,3)-galactosyltransferase activity responsible for the synthesis of AG glycans that are present on both AGPs and/or the pectic polysaccharide rhamnogalacturonan I. These data demonstrate that defects in AGP/pectic glycans, caused by disruption of KNS4 function, impact pollen development and viability in Arabidopsis.Pollen, the male gametophyte of all seed plants, is crucial for reproductive success. Due to the harsh environmental conditions that pollen must survive in, it has developed an elaborate and specialized cell wall. However, despite its importance our knowledge of the fine structure and assembly of the pollen grain wall is poorly understood (Newbigin et al., 2009;Ariizumi and Toriyama, 2011;Quilichini et al., 2015;Shi et al., 2015). Arabidopsis (Arabidopsis thaliana) provides an ideal genetic and cell biological model to dissect the assembly of the components of the pollen grain wall. Arabidopsis pollen grains have a typical surface structure that consists of an inner intine layer, which is usually made up of cellulose and pectin, and the outer exine, which is largely composed of sporopollenin (Li et al., 1995). The exine is further subdivided into inner nexine and outer sexine. The sexine has a three-dimensional (3D) structure composed of many columns called baculae and a roof called tectum. These two structures give the Arabidopsis pollen surface a reticulate appearance with a uniform mesh size. The nexine is composed of outer nexine I (foot layer), which contains sporopollenin, and inner nexine II (endexine; Ariizumi and Toriyama, 2011;Jiang et al., 2013). A recent study suggests that arabinogalactan proteins (AGPs) are key constituents of nexine with express...

show abstract

Early germination of Arabidopsis pollen in a double null mutant for the arabinogalactan protein genes AGP6 and AGP11

Cited by 57 publications

References 23 publications

Pipeline to Identify Hydroxyproline-Rich Glycoproteins

Pipeline to Identify Hydroxyproline-Rich Glycoproteins

Arabinogalactan Proteins in Arabidopsis thaliana Pollen Development

KNS4/UPEX1: A Type II Arabinogalactan β-(1,3)-Galactosyltransferase Required for Pollen Exine Development

Contact Info

Product

Resources

About