Plant architecture is one of the key factors that affect plant survival and productivity. Plant body structure is established through the iterative initiation and outgrowth of lateral organs, which are derived from the shoot apical meristem and root apical meristem, after embryogenesis. Here we report that ADP1, a putative MATE (multidrug and toxic compound extrusion) transporter, plays an essential role in regulating lateral organ outgrowth, and thus in maintaining normal architecture of Arabidopsis. Elevated expression levels of ADP1 resulted in accelerated plant growth rate, and increased the numbers of axillary branches and flowers. Our molecular and genetic evidence demonstrated that the phenotypes of plants over-expressing ADP1 were caused by reduction of local auxin levels in the meristematic regions. We further discovered that this reduction was probably due to decreased levels of auxin biosynthesis in the local meristematic regions based on the measured reduction in IAA levels and the gene expression data. Simultaneous inactivation of ADP1 and its three closest homologs led to growth retardation, relative reduction of lateral organ number and slightly elevated auxin level. Our results indicated that ADP1-mediated regulation of the local auxin level in meristematic regions is an essential determinant for plant architecture maintenance by restraining the outgrowth of lateral organs.

• MeSH
• Arabidopsis genetika   růst a vývoj   MeSH
• kořeny rostlin genetika   růst a vývoj   metabolismus   MeSH
• květy genetika   růst a vývoj   MeSH
• kyseliny indoloctové metabolismus   MeSH
• meristém růst a vývoj   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• proteiny přenášející organické kationty genetika   MeSH
• regulace genové exprese u rostlin MeSH
• výhonky rostlin genetika   růst a vývoj   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Phosphoglycerolipids are essential structural constituents of membranes and some also have important cell signalling roles. In this review, we focus on phosphoglycerolipids that are mediators in hormone signal transduction in plants. We first describe the structures of the main signalling phosphoglycerolipids and the metabolic pathways that generate them, namely the phospholipase and lipid kinase pathways. In silico analysis of Arabidopsis transcriptome data provides evidence that the genes encoding the enzymes of these pathways are transcriptionally regulated in responses to hormones, suggesting some link with hormone signal transduction. The involvement of phosphoglycerolipid signalling in the early responses to abscisic acid, salicylic acid and auxins is then detailed. One of the most important signalling lipids in plants is phosphatidic acid. It can activate or inactivate protein kinases and/or protein phosphatases involved in hormone signalling. It can also activate NADPH oxidase leading to the production of reactive oxygen species. We will interrogate the mechanisms that allow the activation/deactivation of the lipid pathways, in particular the roles of G proteins and calcium. Mediating lipids thus appear as master players of cell signalling, modulating, if not controlling, major transducing steps of hormone signals.

• MeSH
• Arabidopsis fyziologie   MeSH
• fosfolipasy metabolismus   MeSH
• fosfotransferasy metabolismus   MeSH
• glycerofosfolipidy metabolismus   MeSH
• kyselina abscisová metabolismus   MeSH
• kyseliny fosfatidové metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné proteiny metabolismus   MeSH
• rostliny MeSH
• signální transdukce fyziologie   MeSH
• transkriptom MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Nucleolin is the major nucleolar protein of animal, plant and yeast proliferating cells. It is enriched in the most soluble nuclear or nucleolar protein extract, containing ribonucleoproteins, from which it has been purified. It has a tripartite structure in which each domain accounts for different functions. Despite its multifunctionality, the best characterized role of nucleolin is in the primary cleavage of pre-rRNA, an early step of ribosome biogenesis. In the nucleolus of proliferating cells, nucleolin is mostly located in the dense fibrillar component, following a vectorial pattern, from the periphery of fibrillar centers outwards. This pattern is lost in quiescent cells in which nucleolin is present in low levels. Nucleolin is the most phosphorylated protein of the soluble nuclear extract. It is phosphorylated by casein kinase II and CDKA, and phosphorylation is closely associated with the role of nucleolin in proliferating cells. During mitosis, nucleolin is transported from the mother to the daughter cell nucleolus in the form of processing particles, together with pre-rRNA precursors and other nucleolar proteins. It forms part of prenucleolar bodies and plays a role in nucleologenesis. Recent studies on the nucleolin function, carried out on samples with inactivated nucleolin genes (siRNA downregulated or mutants) have evidenced that nucleolin is absolutely essential for cell proliferation, for the organization of the nucleolus and for transcription and processing of pre-rRNA. In plants, nucleolin controls the auxin responsiveness, thus being involved in the regulation of plant development.

• MeSH
• biogeneze organel MeSH
• buněčný cyklus fyziologie   genetika   MeSH
• fosfoproteiny biosyntéza   genetika   chemie   MeSH
• fosforylace fyziologie   genetika   MeSH
• jaderné proteiny biosyntéza   genetika   chemie   MeSH
• klinické laboratorní techniky využití   MeSH
• kvasinky MeSH
• kyseliny indoloctové MeSH
• prekurzory RNA biosyntéza   genetika   chemie   MeSH
• proliferace buněk MeSH
• proteiny vázající RNA biosyntéza   genetika   chemie   MeSH
• ribonukleoproteiny malé jadérkové biosyntéza   MeSH
• ribozomy genetika   chemie   MeSH
• rostliny MeSH
• statistika jako téma MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• přehledy MeSH