“…Plants homozygous for mutations in COW1 and TIP1 produce short, wide root hairs, and sometimes multiple hairs form at a single site of hair formation (Schiefelbein et al, 1993;Grierson et al, 1997;Ryan et al, 1998). Plants homozygous for mutations in RHD3 and RHD4 have short, wavy root hairs (Schiefelbein and Somerville, 1990;Galway et al, 1997Galway et al, , 1999Wang et al, 1997).…”