Organ specific expression patterns of mot1 family members. Histochemical GUS assay of transgenic A. thaliana carrying mot1.1::gus (A–C). Root tip (A), mature root (B), and old leaf (C) are shown. Histochemical (E–G) GUS assay of transgenic A. thaliana carrying mot1.2::gus showing mature root ((E); i = unstained root periphery, ii = stained central cylinder), rosette leaves of increasing age ((F); (i) young, (ii) middle-aged, (iii) old) and developing fruit (G). Scale bars = 500 µm (A,B,E,G) and 3000 µm (C,F). Fluorimetric GUS assay (D,H) showing GUS activity of three independent (L1–L3) mot1.1::gus plant lines and one mot1.2::gus line grown with molybdate availability (+) and deprivation (−) in roots, young and old leaves.