Affordable Access

deepdyve-link
Publisher Website

Apyrase (nucleoside triphosphate-diphosphohydrolase) and extracellular nucleotides regulate cotton fiber elongation in cultured ovules.

Authors
  • Clark, Greg
  • Torres, Jonathan
  • Finlayson, Scott
  • Guan, Xueying
  • Handley, Craig
  • Lee, Jinsuk
  • Kays, Julia E
  • Chen, Z Jeffery
  • Roux, Stanley J
Type
Published Article
Journal
PLANT PHYSIOLOGY
Publisher
American Society of Plant Biologists
Publication Date
Feb 01, 2010
Volume
152
Issue
2
Pages
1073–1083
Identifiers
DOI: 10.1104/pp.109.147637
PMID: 20018604
Source
Medline
License
Unknown

Abstract

Ectoapyrase enzymes remove the terminal phosphate from extracellular nucleoside tri- and diphosphates. In Arabidopsis (Arabidopsis thaliana), two ectoapyrases, AtAPY1 and AtAPY2, have been implicated as key modulators of growth. In fibers of cotton (Gossypium hirsutum), transcript levels for GhAPY1 and GhAPY2, two closely related ectoapyrases that have high sequence similarity to AtAPY1 and AtAPY2, are up-regulated when fibers enter their rapid growth phase. In an ovule culture system, fibers release ATP as they grow, and when their ectoapyrase activity is blocked by the addition of polyclonal anti-apyrase antibodies or by two different small molecule inhibitors, the medium ATP level rises and fiber growth is suppressed. High concentrations of the poorly hydrolyzable nucleotides ATPgammaS and ADPbetaS applied to the medium inhibit fiber growth, and low concentrations of them stimulate growth, but treatment with adenosine 5'-O-thiomonophosphate causes no change in the growth rate. Both the inhibition and stimulation of growth by applied nucleotides can be blocked by an antagonist that blocks purinoceptors in animal cells, and by adenosine. Treatment of cotton ovule cultures with ATPgammaS induces increased levels of ethylene, and two ethylene antagonists, aminovinylglycine and silver nitrate, block both the growth stimulatory and growth inhibitory effects of applied nucleotides. In addition, the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, lowers the concentration of nucleotide needed to promote fiber growth. These data indicate that ectoapyrases and extracellular nucleotides play a significant role in regulating cotton fiber growth and that ethylene is a likely downstream component of the signaling pathway.

Report this publication

Statistics

Seen <100 times