AUTHOR=Gigli Bisceglia Nora , Savatin Daniel V. , Cervone Felice , Engelsdorf Timo , De Lorenzo Giulia 

TITLE=Loss of the Arabidopsis Protein Kinases ANPs Affects Root Cell Wall Composition, and Triggers the Cell Wall Damage Syndrome

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.02234

DOI=10.3389/fpls.2017.02234

ISSN=1664-462X

ABSTRACT=<p>The Arabidopsis NPK1-related Protein kinases ANP1, ANP2 and ANP3 belong to the MAP kinase kinase kinase (MAPKKK) superfamily and were previously described to be crucial for cytokinesis, elicitor-induced immunity and development. Here we investigate the basis of their role in development by using conditional β-estradiol-inducible triple mutants to overcome lethality. In seedlings, lack of ANPs causes root cell bulging, with the transition zone being the most sensitive region. We uncover a role of ANPs in the regulation of cell wall composition and suggest that developmental defects of the triple mutants, observed at the cellular level, might be a consequence of the alterations of the pectic and cellulosic cell wall components. Lack of ANPs also induced a typical cell wall damage syndrome (CWDS) similar to that observed in plants treated with the cellulose biosynthesis inhibitor isoxaben (ISX). Moreover, <italic>anp</italic> double mutants and plants overexpressing single ANPs (<italic>ANP1</italic> or <italic>ANP3</italic>) respectively showed increased and reduced accumulation of jasmonic acid and <italic>PDF1.2</italic> transcripts upon ISX treatment, suggesting that ANPs are part of the pathway targeted by this inhibitor and play a role in cell wall integrity surveillance.</p><p><bold>Highlights</bold>: The loss of ANP function affects cell wall composition and leads to typical cell wall damage-induced phenotypes, such as ectopic lignification and jasmonic acid accumulation.</p>