Nejvíce citovaný článek - PubMed ID 1831768
The long-standing Acid Growth Theory of plant cell elongation posits that auxin promotes cell elongation by stimulating cell wall acidification and thus expansin action. To date, the paucity of pertinent genetic materials has precluded thorough analysis of the importance of this concept in roots. The recent isolation of mutants of the model grass species Brachypodium distachyon with dramatically enhanced root cell elongation due to increased cellular auxin levels has allowed us to address this question. We found that the primary transcriptomic effect associated with elevated steady state auxin concentration in elongating root cells is upregulation of cell wall remodeling factors, notably expansins, while plant hormone signaling pathways maintain remarkable homeostasis. These changes are specifically accompanied by reduced cell wall arabinogalactan complexity but not by increased proton excretion. On the contrary, we observed a tendency for decreased rather than increased proton extrusion from root elongation zones with higher cellular auxin levels. Moreover, similar to Brachypodium, root cell elongation is, in general, robustly buffered against external pH fluctuation in Arabidopsis thaliana However, forced acidification through artificial proton pump activation inhibits root cell elongation. Thus, the interplay between auxin, proton pump activation, and expansin action may be more flexible in roots than in shoots.
- MeSH
- Brachypodium metabolismus MeSH
- buněčná stěna metabolismus MeSH
- galaktany metabolismus MeSH
- kořeny rostlin metabolismus MeSH
- kyseliny indoloctové metabolismus MeSH
- signální transdukce fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- arabinogalactan MeSH Prohlížeč
- galaktany MeSH
- kyseliny indoloctové MeSH
Classical isolation procedure for plasma membrane H(+)-ATPase of Saccharomyces cerevisiae based on fractional centrifugation yielded always a roughly two-fold greater amount of membranes when starting from glucitol-preincubated than from glucose-preincubated yeast. This difference persisted all the way to the purified plasma membranes and to the purified H(+)-ATPase. The ATP-hydrolyzing activity by plasma membranes was roughly twice greater in glucose-preincubated cells than in the D-glucitol-preincubated ones while the purified enzyme was 7 times more active after glucose than after glucitol. Effects of diethylstilbestrol, suloctidil, erythrosin B, vanadate and dicarbanonaboranuide were very similar on plasma membrane-localized and purified ATPases of both forms, suggesting that both preparations contain the two ATPase forms, the glucose-preincubated one being richer in the activated form while the glucitol-preincubated one contains less of it.
- MeSH
- adenosintrifosfát metabolismus MeSH
- buněčná membrána enzymologie MeSH
- inhibitory enzymů farmakologie MeSH
- kultivační média MeSH
- protonové ATPasy antagonisté a inhibitory izolace a purifikace metabolismus MeSH
- Saccharomyces cerevisiae enzymologie růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenosintrifosfát MeSH
- inhibitory enzymů MeSH
- kultivační média MeSH
- protonové ATPasy MeSH
- MeSH
- aktivní transport MeSH
- draslík metabolismus MeSH
- fungální proteiny metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- membránové proteiny metabolismus MeSH
- proteiny přenášející kationty * MeSH
- protony * MeSH
- rubidium metabolismus MeSH
- Saccharomyces cerevisiae - proteiny * MeSH
- Saccharomyces cerevisiae metabolismus MeSH
- thallium metabolismus MeSH
- transportní proteiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- draslík MeSH
- fungální proteiny MeSH
- membránové proteiny MeSH
- proteiny přenášející kationty * MeSH
- protony * MeSH
- rubidium MeSH
- Saccharomyces cerevisiae - proteiny * MeSH
- thallium MeSH
- transportní proteiny MeSH
- TRK1 protein, S cerevisiae MeSH Prohlížeč
- TRK2 protein, S cerevisiae MeSH Prohlížeč
