Suppression of Dwarf and irregular xylem Phenotypes Generates Low-Acetylated Biomass Lines in Arabidopsis

• Published in: Plant Physiology
• Main Authors: Bensussan, Matthieu, Lefebvre, Valérie, Ducamp, Aloise, Trouverie, Jacques, Gineau, Emilie, Vallery-Radot, Marie-Noëlle, Guillebaux, Alexia, Baldy, Aurélie, Naquin, Delphine, Herbette, Stéphane, Lapierre, Catherine, Mouille, Gregory, Horlow, Christine, Durand-Tardif, Marie-Hélène
• Other Authors: Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Centre de génétique moléculaire (CGM), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier (PIAF), Institut National de la Recherche Agronomique (INRA)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP), Ecophysiologie Végétale, Agronomie et Nutritions (EVA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Recherche Agronomique (INRA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: [SDV]Life Sciences [q-bio]; [SDV.BV]Life Sciences [q-bio]/Vegetal Biology; eskimo*
• Online Access: https://hal.science/hal-01204187; https://doi.org/10.1104/pp.15.00122

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.