Physiological and molecular analysis of the interaction between aluminium toxicity and drought stress in common bean (Phaseolus vulgaris)

J Exp Bot. 2012 May;63(8):3109-25. doi: 10.1093/jxb/ers038. Epub 2012 Feb 27.

Abstract

Aluminium (Al) toxicity and drought are two major factors limiting common bean (Phaseolus vulgaris) production in the tropics. Short-term effects of Al toxicity and drought stress on root growth in acid, Al-toxic soil were studied, with special emphasis on Al-drought interaction in the root apex. Root elongation was inhibited by both Al and drought. Combined stresses resulted in a more severe inhibition of root elongation than either stress alone. This result was different from the alleviation of Al toxicity by osmotic stress (-0.60 MPa polyethylene glycol) in hydroponics. However, drought reduced the impact of Al on the root tip, as indicated by the reduction of Al-induced callose formation and MATE expression. Combined Al and drought stress enhanced up-regulation of ACCO expression and synthesis of zeatin riboside, reduced drought-enhanced abscisic acid (ABA) concentration, and expression of NCED involved in ABA biosynthesis and the transcription factors bZIP and MYB, thus affecting the regulation of ABA-dependent genes (SUS, PvLEA18, KS-DHN, and LTP) in root tips. The results provide circumstantial evidence that in soil, drought alleviates Al injury, but Al renders the root apex more drought-sensitive, particularly by impacting the gene regulatory network involved in ABA signal transduction and cross-talk with other phytohormones necessary for maintaining root growth under drought.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / biosynthesis
  • Aluminum / toxicity*
  • Biosynthetic Pathways / drug effects
  • Biosynthetic Pathways / genetics
  • Cell Wall / drug effects
  • Cell Wall / genetics
  • Colombia
  • Cytokinins / biosynthesis*
  • Droughts*
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Plant / genetics
  • Genotype
  • Glucans / metabolism
  • Isopentenyladenosine / analogs & derivatives
  • Isopentenyladenosine / metabolism
  • Models, Biological
  • Osmotic Pressure / drug effects
  • Phaseolus / drug effects
  • Phaseolus / genetics*
  • Phaseolus / physiology*
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plant Roots / physiology
  • Seedlings / drug effects
  • Seedlings / growth & development
  • Stress, Physiological / drug effects*
  • Stress, Physiological / genetics*

Substances

  • Cytokinins
  • Glucans
  • Abscisic Acid
  • Isopentenyladenosine
  • zeatin riboside
  • callose
  • Aluminum