Genome-wide expression analysis of rice aquaporin genes and development of a functional gene network mediated by aquaporin expression in roots

Planta. 2013 Oct;238(4):669-81. doi: 10.1007/s00425-013-1918-9. Epub 2013 Jun 26.

Abstract

The world population continually faces challenges of water scarcity for agriculture. A common strategy called water-balance control has evolved to adapt plant growth to these challenges. Aquaporins are a family of integral membrane proteins that play a central role in water-balance control. In this study, we identified 34 members of the rice aquaporin gene family, adding a novel member to the previous list. A combination of phylogenetic tree and anatomical meta-expression profiling data consisting of 983 Affymetrix arrays and 209 Agilent 44 K arrays was used to identify tissue-preferred aquaporin genes and evaluate functional redundancy among aquaporin family members. Eight aquaporins showed root-preferred expression in the vegetative growth stage, while 4 showed leaf/shoot-preferred expression. Integrating stress-induced expression patterns into phylogenetic tree and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that 3 rice aquaporin genes were markedly downregulated and 4 were upregulated by water deficiency in the root, suggesting that these candidate genes are key regulators of water uptake from the soil. Finally, we constructed a functional network of genes mediated by water stress and refined the network by confirming the differential expression using RT-PCR and real-time PCR. Our data will be useful to elucidate the molecular mechanism of water-balance control in rice root.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aquaporins / genetics*
  • Aquaporins / metabolism
  • Droughts
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Gene Regulatory Networks
  • Oryza / genetics*
  • Oryza / metabolism
  • Phylogeny
  • Plant Roots / metabolism*
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stress, Physiological
  • Water / physiology

Substances

  • Aquaporins
  • Water