TIP1 is required for both tip growth and non‐tip growth in Arabidopsis

Abstract

TIP1 is a gene defined by an X‐ray induced allele tip1–2 and a previously described EMS‐induced allele tip1−1. TIP1 is involved in plant cell growth. tip1–2 plants display growth defects throughout the plant and exhibit defects in both root‐hair and pollen‐tube growth. tip1–2 plants are partly male sterile resulting from a combination of pollen germination and pollen‐tube defects; their root‐hairs are short, exhibit a tendency to branch and 2–4 hairs can initiate from each hair cell. They are also slightly dwarf in stature as a result of a general decrease in cell growth indicating that TIP1 activity is required for general cell growth. We propose a role for TIP in both the initiation and maintenance of growth in tip‐growing cells. In addition TIP1 activity is required for normal cell expansion (non‐tip cell growth) indicating that TIP1 is not exclusively involved in tip‐growth.