Non-inductive conditions expose the cryptic bract of flower phytomeres in Arabidopsis thaliana

Müller-Xing R, Schubert D, Goodrich J – 2015

The aerial plant architecture is built by phytomeres which are metameric units, each composed of a stem segment (internode) and a leaf with axillary meristem (node). In Arabidopsis thaliana, fully developed flower phytomeres lack the leaf even if they temporarily exhibit a cryptic bract (CB) during early development. Recently, we demonstrated that the CB becomes more prominent under non-inductive short-day conditions. However, a full outgrowth as cauline leaf is prevented by Polycomb-group (Pc-G) proteins which silence the MADS gene FLOWERING LOCUS C (FLC) encoding a repressor of FLOWERING LOCUS T (FT). Also the loss of SHORT VEGETATIVE PHASE (SVP) supresses ectopic leaves at the base of Pc-G deficient pedicels. Here we present new expression data of flowering genes LEAFY (LFY) and TWIN SISTER OF FT (TSF) and the re-analysis of morphological changes in Pc-G deficient plants suggesting that the specifications of CB and floral meristem (FM) are separated in time.

Non-inductive conditions expose the cryptic bract of flower phytomeres in Arabidopsis thaliana
Müller-Xing R, Schubert D, Goodrich J
Taylor & Francis
Arabidopsis; CB, cryptic bract; FLC, FLOWERING LOCUS C; FM, floral meristem; FT, FLOWERING LOCUS T; IM, inflorescence meristem; LFY, LEAFY; P0, P1, etc., numbering of floral primordia; Pc-G, Polycomb-group; RB, rudimentary bract; SAM, shoot apical meristem; STM, SHOOT MERISTEMLESS; SVP, SHORT VEGETATIVE PHASE; St1, floral stage 1 etc; Ste2, early floral stage 2; Stl2, late floral stage 2; TSF, TWIN SISTER OF FT.; cell specification; ev, emf2-10 vrn2-1; floral primordia; floral reversion; iCLF, clf-28 swn-7 CLF-GR; plant morphology; rIM, reverted inflorescence meristem
doi: 10.1080/15592324.2015.1010868
Appeared in
Plant signaling & behavior, 10(4): e1010868
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