GAUT10 is required for Arabidopsis root cell differentiation and elongation

Abstract

O_LICell wall properties of the root apical meristem (RAM) are poorly understood compared to the elongation and maturation zones of the developing root. GAUT10 is a pectin biosynthesizing enzyme that is post-transcriptionally regulated by auxin that influences Arabidopsis RAM size in a sucrose-dependent manner. C_LIO_LIUsing live-cell microscopy, we have determined the short root phenotype of the gaut10 loss of function allele is due to a reduction in both RAM cell number and epidermal cell elongation. In addition, the absence of GAUT10 leads to a reduction in lateral root cap and epidermal cell marker line expression, indicating root cell differentiation defects in this mutant. C_LIO_LIGAUT10 is required for normal pectin and hemicellulose composition in primary Arabidopsis roots. Loss of GAUT10 leads to a reduction in galacturonic acid and xylose in primary cell walls and alters the presence of rhamnogalacturonan (RG) I and homogalacturonan (HG) polymers in the root. C_LIO_LIAuxin mediated gene expression and metabolism is altered in gaut10 roots, suggesting that cell wall composition may influence auxin pathways. C_LI