African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12294

Full Length Research Paper

The effects of calcium on the expression of genes involved in ethylene biosynthesis and signal perception during tomato flower abscission

Tao Xu, Mingfang Qi, Shuangshuang Lv, Xianhong Zuo, Jinhong Li and Tianlai Li*
College of Horticulture, Shenyang Agricultural University, Shenyang, Liaoning, 110161, P. R. China
Email: [email protected]

  •  Accepted: 06 May 2010
  •  Published: 14 June 2010

Abstract

 

Calcium regulation of the genes involved in ethylene biosynthesis and ethylene receptors in flower abscission zones (AZ) of wild-type tomato (Lycopersicon esculentum Mill.) was investigated in this study. Calcium treatment delayed abscission of pedicel explants. However, verapamil (VP, calcium inhibitor) treatments accelerated abscission. Results showed an increase in AZ ethylene production consistent with abscission in both control and treatment explants. Moreover, in the AZ of flower pedicels treated with VP, ethylene production,LeACO1 and LeETR1 expression was elevated, but LeETR4 expression decreased. Calcium treatments delayed the onset and maximum ethylene production, maintained low LeACO1 expression and elevated LeETR2, 3, 4, 5expressions. Results also found that VP and calcium had little effect on LeACS2expression. Our hypothesis that calcium is integral in preventing ethylene production at the point when 1-aminocyclopropane-1-carboxylic acid (ACC) is converted to ethylene was supported, but the study also revealed the regulation of expression in the ethylene receptors. The potential roles of LeACO1LeETR 3, 4, 5and calcium in AZs during tomato pedicel explants abscission are discussed.

 

Key words: Abscission, ethylene receptor, calcium, tomato.

Abbreviation

AZ, Abscission zones; VP, verapamil; SAM, S-adenosylmethionine;ACC,1-aminocyclopropane-1-carboxylic acid; ACS, 1-aminocyclopropane-1-carboxylic acid synthase; ACO, 1-aminocyclopropane-1-carboxylic acid oxidase;ETRs, ethylene receptors; SDS, sodium deodecyl sulfate; AR, abscission rate;CDPK, calcium-dependent protein kinase; 1-MCP, 1-methylcyclopropene.