Suppression of Dwarf and irregular xylem Phenotypes Generates Low-Acetylated Biomass Lines in Arabidopsis  . Issue 2 (17th April 2015)

• Record Type: Journal Article
• Authors: Bensussan, Matthieu; Lefebvre, Valérie; Ducamp, Aloïse; Trouverie, Jacques; Gineau, Emilie; Fortabat, Marie-Noëlle; Guillebaux, Alexia; Baldy, Aurélie; Naquin, Delphine; Herbette, Stéphane; Lapierre, Catherine; Mouille, Gregory; Horlow, Christine; Durand-Tardif, Mylène
• Is Part Of: Plant physiology. Volume 168:Issue 2(2015)
• Page Start: 452
• Page End: 463
• Publication Date: 2015-04-17
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.15.00122
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Inactivation of ubiquitin-ligase3 suppresses dwarfism and irregular xylem in an Arabidopsis mutant, generating a line with low acetylated biomass and high glucose release after cellulolysis. Abstract: eskimo1 -5 ( esk1-5 ) is a dwarf Arabidopsis ( Arabidopsis thaliana ) mutant that has a constitutive drought syndrome and collapsed xylem vessels, along with low acetylation levels in xylan and mannan. ESK1 has xylan O -acetyltransferase activity in vitro. We used a suppressor strategy on esk1-5 to screen for variants with wild-type growth and low acetylation levels, a favorable combination for ethanol production. We found a recessive mutation in the KAKTUS ( KAK ) gene that suppressed dwarfism and the collapsed xylem character, the cause of decreased hydraulic conductivity in the esk1-5 mutant. Backcrosses between esk1-5 and two independent knockout kak mutants confirmed suppression of the esk1-5 effect. kak single mutants showed larger stem diameters than the wild type. The KAK promoter fused with a reporter gene showed activity in the vascular cambium, phloem, and primary xylem in the stem and hypocotyl. However, suppression of the collapsed xylem phenotype in esk1 kak double mutants was not associated with the recovery of cell wall O -acetylation or any major cell wall modifications. Therefore, our results indicate that, in addition to its described activity as a repressor of endoreduplication, KAK may play a role in vascular development. Furthermore, orthologous esk1 kak double mutants may hold promise for ethanol production in crop plants.