The phosphate transporter PHT4;6 locates to the trans-Golgi compartment, and its impaired activity causes altered intracellular phosphate compartmentation, leading to low cytosolic Pi levels, a blockage of Golgi-related processes such as protein glycosylation and hemicellulose biosynthesis, and a dwarf phenotype. However, it was unclear whether altered Pi homeostasis in pht4;6 mutants causes further cellular problems, typically associated with limited phosphate availability. Here we report that pht4;6 mutants exhibit a markedly increased disposition to induce dark-induced senescence. In control experiments, in which pht4;6 mutants and wild-type plants developed similarly, we confirmed that accelerated dark-induced senescence in mutants is not a 'pleiotropic' process associated with the dwarf phenotype. In fact, accelerated dark-induced senescence in pht4;6 mutants correlates strongly with increased levels of toxic NH4 (+) and higher sensitivity to ammonium, which probably contribute to the inability of pht4;6 mutants to recover from dark treatment. Experiments with modified levels of either salicylic acid (SA) or trans-zeatin (tZ) demonstrate that altered concentrations of these compounds in pht4;6 plants act as major cellular mediators for dark-induced senescence. This conclusion gained further support from the notion that the expression of the pht4;6 gene is, in contrast to genes coding for major phosphate importers, substantially induced by tZ. Taken together, our findings point to a critical function of PHT4;6 to control cellular phosphate levels, in particular the cytosolic Pi availability, required to energize plant primary metabolism for proper plant development. Phosphate and its allocation mediated by PHT4;6 is critical to prevent onset of dark-induced senescence.
- MeSH
- Arabidopsis metabolism physiology MeSH
- Chlorophyll metabolism MeSH
- Cytokinins metabolism MeSH
- Golgi Apparatus metabolism physiology MeSH
- Arabidopsis Proteins physiology MeSH
- Phosphate Transport Proteins physiology MeSH
- Gene Expression Regulation, Plant physiology MeSH
- Aging physiology MeSH
- Light MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Progress in clinical and biological research ; Vol. 252
xxiii, 426 s. : obr., tab.
- MeSH
- Phosphates MeSH
- Phosphorus MeSH
- Membrane Transport Proteins MeSH
- Calcium MeSH
- Publication type
- Congress MeSH
- Collected Work MeSH
- Conspectus
- Biochemie. Molekulární biologie. Biofyzika
- NML Fields
- biochemie
- gastroenterologie
- endokrinologie
... (2-CHLOROETHYL) PHOSPHATE -- PREAMBLE x -- ABBREVIATIONS xix -- TRIS(CHLOROPROPYL) PHOSPHATE 1 -- 1. ... ... SUMMARY 2 -- ^ 1.1 Tris(l-chloro-2-propyl) phosphate (TCPP) 2 -- 1.2 Tris(l,3-dichloro-2-propyl) phosphate ... ... ENVIRONMENTAL TRANSPORT, DISTRIBUTION -- AND TRANSFORMATION 15 -- 4.1 Transport and distribution between ... ... FURTHER RESEARCH 50 -- TRIS(2-CHLOROETHYL) PHOSPHATE 51 -- Al. SUMMARY 52 -- A2. ... ... ENVIRONMENTAL TRANSPORT, DISTRIBUTION -- AND TRANSFORMATION 59 -- A4.1 Transport and distribution between ...
Environmental health criteria, ISSN 0250-863X No. 209
xix, 106 s. ; 20 cm
- Keywords
- zpomalovače hoření,
- MeSH
- Organophosphates adverse effects toxicity MeSH
- Flame Retardants adverse effects toxicity MeSH
- Environmental Exposure MeSH
- Conspectus
- Lékařské vědy. Lékařství
- NML Fields
- environmentální vědy
- toxikologie
- environmentální vědy
- NML Publication type
- publikace WHO
