Lack of the Golgi phosphate transporter PHT4;6 causes strong developmental defects, constitutively activated disease resistance mechanisms and altered intracellular phosphate compartmentation in Arabidopsis
Articolo
Data di Pubblicazione:
2012
Citazione:
Lack of the Golgi phosphate transporter PHT4;6 causes strong developmental defects, constitutively activated disease resistance mechanisms and altered intracellular phosphate compartmentation in Arabidopsis / S. Hassler, L. Lemke, B. Jung, T. Möhlmann, F. Krüger, K. Schumacher, L. Espen, E. Martinoia, H.E. Neuhaus. - In: PLANT JOURNAL. - ISSN 0960-7412. - 72:5(2012 Dec), pp. 732-744. [10.1111/j.1365-313X.2012.05106.x]
Abstract:
The Golgi-located phosphate exporter PHT4;6 has been described as involved in salt tolerance but further
analysis on the physiological impact of PHT4;6 remained elusive. Here we show that PHT4;6–GFP is targeted to
the trans-Golgi compartment and that loss of function of this carrier protein has a dramatic impact on plant
growth and development. Knockout mutants of pht4;6 exhibit a dwarf phenotype that is complemented by the
homologous gene from rice (Oryza sativa). Interestingly, pht4;6 mutants show altered characteristics of several
Golgi-related functions, such as an altered abundance of certain N-glycosylated proteins, altered composition
of cell-wall hemicelluose, and higher sensitivity to the Golgi a-mannosidase and the retrograde transport
inhibitors kifunensine and brefeldin A, respectively. Moreover, pht4;6 mutants exhibit a ‘mimic disease’
phenotype accompanied by constitutively activated pathogen defense mechanisms and increased resistance
against the virulent Pseudomonas syringae strain DC3000. Surprisingly, pht4;6 mutants also exhibit phosphate
starvation symptoms, as revealed at the morphological and molecular level, although total Pi levels in wildtype
and pht4;6 plants are similar. This suggested that subcellular Pi compartmentation was impaired. By use
of nuclear magnetic resonance (NMR), increased Pi concentration was detected in acidic compartments of
pht4;6 mutants. We propose that impaired Pi efflux from the trans-Golgi lumen results in accumulation of
inorganic phosphate in other internal compartments, leading to low cytoplasmic phosphate levels with
detrimental effects on plant performance.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Alkaloids ; Arabidopsis ; Arabidopsis Proteins ; Brefeldin A ; Cell Wall ; Disease Resistance ; Gene Knockdown Techniques ; Genetic Complementation Test ; Golgi Apparatus ; Mutation ; Oryza sativa ; Phosphate Transport Proteins ; Plant Diseases ; Plants ; Genetically Modified ; Polysaccharides ; Pseudomonas syringae ; alpha-Mannosidase
Elenco autori:
S. Hassler, L. Lemke, B. Jung, T. Möhlmann, F. Krüger, K. Schumacher, L. Espen, E. Martinoia, H.E. Neuhaus
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