Boron supply maintains efficient antioxidant system, cell wall components and reduces aluminum concentration in roots of trifoliate orange

Plant Physiol Biochem. 2019 Apr:137:93-101. doi: 10.1016/j.plaphy.2019.02.003. Epub 2019 Feb 8.

Abstract

Aluminum (Al) toxicity in the acid soils (pH ≤ 5) is the major limiting abiotic factor affecting the productivity of crops. Boron (B) has been reported to alleviate Al toxicity. In spite of recent advances, it is not clear how B relieves Al toxicity. Results demonstrated that Al toxicity hampered the root elongation. Moreover, lumogallion fluorescent molecular probe unequivocally localized mostly bound Al to the periphery of the cell wall (CW) and to the nuclei. Additionally, Al toxicity induced variations in the CW components through the accumulation of pectin and hemicellulose. Nevertheless, B supply reduced callose deposition, increased root growth and reduced changes in the CW components under Al toxicity. Moreover, B supply reduced the un-methylated pectin while increased the degree of methyl esterification of pectin. These results imply that B due to its role in the CW formation could reduce aluminum-induced negative effects on plant growth by attenuating apoplastic Al3+ and changes in the CW components which ultimately results in the improved root growth.

Keywords: Aluminum toxicity; Boron; Cell wall components; Confocal microscopy; Lumogallion.

MeSH terms

  • Aluminum / analysis
  • Aluminum / pharmacokinetics
  • Aluminum / toxicity*
  • Antioxidants / metabolism*
  • Ascorbic Acid / metabolism
  • Boron / pharmacokinetics
  • Boron / pharmacology*
  • Cell Wall / chemistry
  • Cell Wall / drug effects*
  • Citrus / cytology
  • Citrus / drug effects*
  • Citrus / metabolism
  • Glucans / metabolism
  • Microscopy, Confocal
  • Monoamine Oxidase / metabolism
  • Plant Cells / drug effects
  • Plant Cells / metabolism
  • Plant Leaves / metabolism
  • Plant Proteins / metabolism
  • Plant Roots / drug effects
  • Plant Roots / growth & development
  • Plant Roots / metabolism
  • Principal Component Analysis
  • Xanthine Oxidase / metabolism

Substances

  • Antioxidants
  • Glucans
  • Plant Proteins
  • callose
  • Aluminum
  • Xanthine Oxidase
  • Monoamine Oxidase
  • Boron
  • Ascorbic Acid