Cold Responsive Gene Expression Profiling of Sugarcane and Saccharum spontaneum with Functional Analysis of a Cold Inducible Saccharum Homolog of NOD26-Like Intrinsic Protein to Salt and Water Stress

PLoS One. 2015 May 4;10(5):e0125810. doi: 10.1371/journal.pone.0125810. eCollection 2015.

Abstract

Transcriptome analysis of sugarcane hybrid CP72-1210 (cold susceptible) and Saccharum spontaneum TUS05-05 (cold tolerant) using Sugarcane Assembled Sequences (SAS) from SUCEST-FUN Database showed that a total of 35,340 and 34,698 SAS genes, respectively, were expressed before and after chilling stress. The analysis revealed that more than 600 genes are differentially expressed in each genotype after chilling stress. Blast2Go annotation revealed that the major difference in gene expression profiles between CP72-1210 and TUS05-05 after chilling stress are present in the genes related to the transmembrane transporter activity. To further investigate the relevance of transmembrane transporter activity against abiotic stress tolerance, a S. spontaneum homolog of a NOD26-like major intrinsic protein gene (SspNIP2) was selected for functional analysis, of which expression was induced after chilling stress in the cold tolerant TUS05-05. Quantitative real-time PCR showed that SspNIP2 expression was increased ~2.5 fold at 30 minutes after cold treatment and stayed induced throughout the 24 hours of cold treatment. The amino acid sequence analysis of the cloned SspNIP2 confirmed the presence of six transmembrane domains and two NPA (Asn-Pro-Ala) motifs, signature features of major intrinsic protein families. Amino acid analysis confirmed that four amino acids, comprising the ar/R (aromatic residue/arginine) region responsible for the substrate specificity among MIPs, are conserved among monocot silicon transporters and SspNIP2. Salinity stress test on SspNIP2 transgenic tobacco plants resulted in more vigorous transgenic lines than the non-transgenic tobacco plants, suggesting some degree of tolerance to salt stress conferred by SspNIP2. SspNIP2-transgenic plants, exposed to 2 weeks of water stress without irrigation, developed various degrees of water stress symptom. The water stress test confirmed that the SspNIP2 transgenic lines had lower evapotranspiration rates than non-transgenic lines, suggesting that SspNIP2 transgenic lines showed a slight tolerance to the early water stress compared to wild type plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • Cold Temperature
  • Computational Biology
  • Gene Expression Profiling*
  • Gene Expression Regulation, Plant*
  • High-Throughput Nucleotide Sequencing
  • Molecular Sequence Annotation
  • Molecular Sequence Data
  • Nicotiana / genetics
  • Phenotype
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Saccharum / genetics*
  • Saccharum / metabolism*
  • Sequence Alignment
  • Stress, Physiological*
  • Transcriptome*

Substances

  • Plant Proteins

Grants and funding

Texas Emerging Technology Fund (Awarded to JAD), Bioenergy Grant from the Office of Economic Development and Tourism, division within the Office of the Governor of the State of Texas. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.