The effects of high steady state auxin levels on root cell elongation in Brachypodium

• Verfasst von: Pacheco-Villalobos, David [VerfasserIn]
• Verfasst von: Díaz-Moreno, Sara M. [VerfasserIn]
• Verfasst von: Schuren, Alja van der [VerfasserIn]
• Verfasst von: Tamaki, Takayuki [VerfasserIn]
• Verfasst von: Kang, Yeon Hee [VerfasserIn]
• Verfasst von: Gujas, Bojan [VerfasserIn]
• Verfasst von: Novak, Ondrej [VerfasserIn]
• Verfasst von: Jaspert, Nina [VerfasserIn]
• Verfasst von: Li, Zhenni [VerfasserIn]
• Verfasst von: Wolf, Sebastian [VerfasserIn]
• Verfasst von: Oecking, Claudia [VerfasserIn]
• Verfasst von: Ljung, Karin [VerfasserIn]
• Verfasst von: Bulone, Vincent [VerfasserIn]
• Verfasst von: Hardtke, Christian S. [VerfasserIn]
• Titel: The effects of high steady state auxin levels on root cell elongation in Brachypodium
• Verf.angabe: David Pacheco-Villalobos, Sara M. Díaz-Moreno, Alja van der Schuren, Takayuki Tamaki, Yeon Hee Kang, Bojan Gujas, Ondrej Novak, Nina Jaspert, Zhenni Li, Sebastian Wolf, Claudia Oecking, Karin Ljung, Vincent Bulone, and Christian S. Hardtke
• E-Jahr: 2016
• Jahr: May 5, 2016
• Umfang: 16 S.
• Fussnoten: Gesehen am 19.10.2020
• Titel Quelle: Enthalten in: The plant cell
• Ort Quelle: Rockville, Md. : Soc., 1989
• Jahr Quelle: 2016
• Band/Heft Quelle: 28(2016), 5, Seite 1009-1024
• ISSN Quelle: 1532-298X
• DOI: doi:10.1105/tpc.15.01057
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1735933392

Abstract

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.