ecular mechanisms by which plant roots respond to the high pH of the rhizosphere

Root cell elongation is thought to be one of the targets of alkaline stress. However, we reported that a difference in the effect of high pH on root growth between barley and tomato was found in cell proliferation and elongation in the root apices. To identify the barley-specific genes for high pH, we investigated the barley transcriptome by RNA-Seq and compared it to tomato, whose root elongation was reduced by pH 8. We identified two genes, NRT2-like and MADS-box genes, as barley-specific high pH-responsive genes. NRT2 is a high-affinity nitrate transporter. MADS-box domains are encoded by a large gene family, one of which regulates nitrate-dependent root development.