ZmDRR206 involves in maintaining cell wall integrity during maize
seedling growth and interaction with the environment
Abstract
Plants adaptively change their cell wall composition and structure
during growth, development, and interactions with environmental
stresses. Dirigent proteins (DIRs) contribute to environmental
adaptations by dynamically reorganizing the cell wall and/or by
generating defense compounds. We established that maize DIR ZmDRR206
(DISEASE RESISTANCE RESPONSE206) mediates maize seedling growth and
disease resistance response by coordinately regulating biosynthesis of
cell wall components for cell wall integrity (CWI) maintenance.
ZmDRR206 responded to pathogen infection by rapidly increasing
its expression. Both mutation and overexpression of ZmDRR206
resulted in similar small kernel and diminished seedling growth; while
ZmDRR206-overexpression increased disease resistance, greater
drought tolerance and reduced photosynthetic activity, thus caused maize
seedlings to show a growth-defense trade-off phenotype. Consistently,
ZmDRR206-overexpression reduced the contents of primary
metabolites and down-regulated the photosynthesis-related genes; while
increased the contents of major cell wall components and defense
phytohormones; up-regulated defense- and cell wall biosynthesis-related
genes in maize seedlings grown under non-stress conditions. Furthermore,
ZmDRR206 physically interacted with ZmCesA10, a secondary cell
wall-specific cellulose synthase catalytic subunit, in yeast and in
planta. Our findings unravel a mechanism that ZmDRR206 maintains
CWI during maize seedling growth, providing opportunities for breeding
strong disease resistance in maize.