Expression of Fragaria vesca PIP aquaporins in response to drought stress: PIP down-regulation correlates with the decline in substrate moisture content

PLoS One. 2013 Sep 23;8(9):e74945. doi: 10.1371/journal.pone.0074945. eCollection 2013.

Abstract

PIP aquaporin responses to drought stress can vary considerably depending on the isoform, tissue, species or level of stress; however, a general down-regulation of these genes is thought to help reduce water loss and prevent backflow of water to the drying soil. It has been suggested therefore, that it may be necessary for the plant to limit aquaporin production during drought stress, but it is unknown whether aquaporin down-regulation is gradual or triggered by a particular intensity of the stress. In this study, ten Fragaria PIP genes were identified from the woodland strawberry (Fragaria vesca L.) genome sequence and characterised at the sequence level. The water relations of F. vesca were investigated and the effect of different intensities of drought stress on the expression of four PIP genes, as well as how drought stress influences their diurnal transcription was determined. PIP down-regulation in the root corresponded to the level of drought stress. Moreover, transcript abundance of two genes highly expressed in the root (FvPIP1;1 and FvPIP2;1) was strongly correlated to the decline in substrate moisture content. The amplitude of diurnal aquaporin expression in the leaves was down-regulated by drought without altering the pattern, but showing an intensity-dependent effect. The results show that transcription of PIP aquaporins can be fine-tuned with the environment in response to declining water availability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aquaporins / chemistry
  • Aquaporins / genetics
  • Aquaporins / metabolism*
  • Circadian Rhythm / genetics
  • Dehydration
  • Down-Regulation / genetics*
  • Droughts*
  • Fragaria / genetics*
  • Fragaria / physiology*
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Molecular Sequence Data
  • Plant Leaves / genetics
  • Plant Leaves / physiology
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Roots / genetics
  • Plant Roots / physiology
  • Stress, Physiological* / genetics
  • Water / metabolism*

Substances

  • Aquaporins
  • Plant Proteins
  • major intrinsic protein, plant
  • Water

Grants and funding

This work was funded by the East Malling Trust for Horticultural Research. DJS acknowledges funding for Applied Rosaceous Genomics from the Autonomous Province of Trento, Italy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.