Regulation of the major vacuolar Ca²⁺ transporter genes, by intercellular Ca²⁺ concentration and abiotic stresses, in tip-burn resistant Brassica oleracea

Mol Biol Rep. 2013 Jan;40(1):177-88. doi: 10.1007/s11033-012-2047-4. Epub 2012 Nov 9.

Abstract

Calcium is an essential plant macronutrient that has unique structural and signaling roles related to tip-burn disorder in Brassica spp. crops. For two types of cabbage inbred lines, tip-burn susceptible and resistant, we measured and compared major macronutrient cations, including Ca(2+), in leaves. In both lines, Ca(2+), Mg(2+), Na(+), and K(+), accumulated more in leaf base than in leaf apex. Ca(2+) and K(+) were >2 times more abundant in the tip-burn resistant line, while Na(+) was higher in the susceptible line. Ca(2+) differences between the two lines resulted from differential accumulation of calcium into cell vacuoles. We profiled major vacuolar Ca(2+) transporters, in both cabbage lines, by growth time and intercellular Ca(2+) concentration. Expression pattern of several Ca(2+) transporter genes differed between tip-burn susceptible and resistant lines by growth time points. We also identified promoter regions of the major Ca(2+) vacuole transporter genes, CAX1, ACA4, and ACA11, which displayed hormonal, light and defense-related cis-acting regulatory elements. Finally, transporter genes in the two cabbage lines responded differently to abiotic stresses, demonstrating diversity in gene regulation among orthologous genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brassica / genetics*
  • Brassica / metabolism*
  • Calcium / metabolism*
  • Calcium-Transporting ATPases / genetics*
  • Cations / metabolism
  • Gene Expression Regulation, Plant
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Proteins / genetics*
  • Stress, Physiological*
  • Vacuoles / metabolism*

Substances

  • Cations
  • Plant Proteins
  • Calcium-Transporting ATPases
  • Calcium