The Physcomitrella patens exocyst subunit EXO70.3d has distinct roles in growth and development, and is essential for completion of the moss life cycle
Language English Country England, Great Britain Media print-electronic
Document type Journal Article
PubMed
28397275
DOI
10.1111/nph.14548
Knihovny.cz E-resources
- Keywords
- EXO70, Physcomitrella patens, auxin, cytokinesis, egg cell development, exocyst, phylogeny, secretory pathway,
- MeSH
- Cell Differentiation MeSH
- Cytokinesis MeSH
- Plant Epidermis metabolism MeSH
- Phylogeny MeSH
- Genetic Pleiotropy MeSH
- Gene Knockout Techniques MeSH
- Gravitation MeSH
- Bryopsida anatomy & histology growth & development metabolism ultrastructure MeSH
- Mutation genetics MeSH
- Likelihood Functions MeSH
- Cell Proliferation MeSH
- Protoplasts metabolism MeSH
- Regeneration MeSH
- Plant Proteins metabolism MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Plant Proteins MeSH
The exocyst, an evolutionarily conserved secretory vesicle-tethering complex, spatially controls exocytosis and membrane turnover in fungi, metazoans and plants. The exocyst subunit EXO70 exists in multiple paralogs in land plants, forming three conserved clades with assumed distinct roles. Here we report functional analysis of the first moss exocyst subunit to be studied, Physcomitrella patens PpEXO70.3d (Pp1s97_91V6), from the, as yet, poorly characterized EXO70.3 clade. Following phylogenetic analysis to confirm the presence of three ancestral land plant EXO70 clades outside angiosperms, we prepared and phenotypically characterized loss-of-function Ppexo70.3d mutants and localized PpEXO70.3d in vivo using green fluorescent protein-tagged protein expression. Disruption of PpEXO70.3d caused pleiotropic cell elongation and differentiation defects in protonemata, altered response towards exogenous auxin, increased endogenous IAA concentrations, along with defects in bud and gametophore development. During mid-archegonia development, an abnormal egg cell is formed and subsequently collapses, resulting in mutant sterility. Mutants exhibited altered cell wall and cuticle deposition, as well as compromised cytokinesis, consistent with the protein localization to the cell plate. Despite some functional redundancy allowing survival of moss lacking PpEXO70.3d, this subunit has an essential role in the moss life cycle, indicating sub-functionalization within the moss EXO70 family.
References provided by Crossref.org
EXO70A2 Is Critical for Exocyst Complex Function in Pollen Development
Regulation of Exocyst Function in Pollen Tube Growth by Phosphorylation of Exocyst Subunit EXO70C2
Evolution of late steps in exocytosis: conservation and specialization of the exocyst complex
SH3Ps-Evolution and Diversity of a Family of Proteins Engaged in Plant Cytokinesis
Developmental plasticity of Arabidopsis hypocotyl is dependent on exocyst complex function