Top

Research Article

Split Viewer

Mol. Cells 2005; 19(3): 342-349

Published online June 30, 2005

© The Korean Society for Molecular and Cellular Biology

Characterization of an Arabidopsis Gene that Mediates Cytokinin Signaling in Shoot Apical Meristem Development

Jae-Hoon Jung, Ju Yun, Yeon-Hee Seo, Chung-Mo Park

Abstract

Cytokinins are adenine derivatives that regulate numerous plant growth and developmental processes, including apical and floral meristem development, stem growth, leaf senescence, apical dominance, and stress tolerance. However, not much is known about how cytokinin biosynthesis and metabolism is regulated. We identified a novel Arabidopsis gene, ALL, encoding an aldolase-like enzyme that regulates cytokinin signaling. An Arabidopsis mutant, all-1D, in which ALL is activated by the nearby insertion of the 35S enhancer, exhibited extreme dwarfism with rolled, dark-green leaves and reduced apical dominance, symptomatic of cytokinin-overproducing mutants. Consistent with this, ARR4 and ARR5, two representative primary cytokinin-responsive genes, were significantly induced in all-1D. Whereas SHOOT MERISTEMLESS (STM) and KNAT1, which regulate meristem development, were also greatly induced, expression of REV and PHV that regulate lateral organ polarity was inhibited. ALL encodes an aldolase-like enzyme that belongs to the HpcH/HpaI aldolase family in prokaryotes and is down-regulated by exogenous cytokinin, possibly through a negative feedback pathway. We propose that ALL is involved in cytokinin biosynthesis or metabolism and acts as a positive regulator of cytokinin signaling during shoot apical meristem development and determination of lateral organ polarity.

Keywords Activation Tagging; Aldolase; Apical Meristem; Arabidopsis; Cytokinin; Signal Transduction.

Article

Research Article

Mol. Cells 2005; 19(3): 342-349

Published online June 30, 2005

Copyright © The Korean Society for Molecular and Cellular Biology.

Characterization of an Arabidopsis Gene that Mediates Cytokinin Signaling in Shoot Apical Meristem Development

Jae-Hoon Jung, Ju Yun, Yeon-Hee Seo, Chung-Mo Park

Abstract

Cytokinins are adenine derivatives that regulate numerous plant growth and developmental processes, including apical and floral meristem development, stem growth, leaf senescence, apical dominance, and stress tolerance. However, not much is known about how cytokinin biosynthesis and metabolism is regulated. We identified a novel Arabidopsis gene, ALL, encoding an aldolase-like enzyme that regulates cytokinin signaling. An Arabidopsis mutant, all-1D, in which ALL is activated by the nearby insertion of the 35S enhancer, exhibited extreme dwarfism with rolled, dark-green leaves and reduced apical dominance, symptomatic of cytokinin-overproducing mutants. Consistent with this, ARR4 and ARR5, two representative primary cytokinin-responsive genes, were significantly induced in all-1D. Whereas SHOOT MERISTEMLESS (STM) and KNAT1, which regulate meristem development, were also greatly induced, expression of REV and PHV that regulate lateral organ polarity was inhibited. ALL encodes an aldolase-like enzyme that belongs to the HpcH/HpaI aldolase family in prokaryotes and is down-regulated by exogenous cytokinin, possibly through a negative feedback pathway. We propose that ALL is involved in cytokinin biosynthesis or metabolism and acts as a positive regulator of cytokinin signaling during shoot apical meristem development and determination of lateral organ polarity.

Keywords: Activation Tagging, Aldolase, Apical Meristem, Arabidopsis, Cytokinin, Signal Transduction.

Mol. Cells
Aug 31, 2022 Vol.45 No.8, pp. 513~602
COVER PICTURE
Cryo-EM structure of human porphyrin transporter ABCB6 (main figure) shows that binding of hemin (inset, magenta) in concert with two glutathione molecules (cyan) primes ABCB6 for high ATP turnover (Kim et al., pp. 575-587).

Share this article on

  • line
  • mail

Molecules and Cells

eISSN 0219-1032
qr-code Download