member of SYP13 Gene Family, PM-associated; The root length of SYP132-overexpressing seedlings was shorter than that of the wild type. Auxin regulates SYP132 in root growth and the geotropic response. The expression of SYP132 is tightly regulated by auxin, and increased expression of SYP132 reduces the content of H+-ATPase protein on the plasma membrane and is involved in the endocytosis of plasma membrane H+-ATPase proteins, reducing their density and activity on the PM