Differentially Expressed Genes Associated with Improved Drought Tolerance in Creeping Bentgrass Overexpressing a Gene for Cytokinin Biosynthesis

PLoS One. 2016 Nov 17;11(11):e0166676. doi: 10.1371/journal.pone.0166676. eCollection 2016.

Abstract

Transformation with an isopentenyl transferase (ipt) gene controlling cytokinin (CK) synthesis has been shown to enhance plant drought tolerance. The objective of this study was to identify differentially-expressed genes (DEGs) in creeping bentgrass (Agrostis stolonifera) overexpressing ipt compared to non-transgenic plants. The ipt transgene was controlled by a senescence-activated promoter (SAG12). Both a null transformed line (NT) and SAG12-ipt plants were exposed to drought stress in an environmentally-controlled growth chamber until the soil water content declined to approximately 5% and leaf relative water content declined to 47%, which were both significantly below the well-watered controls. RNA was extracted from leaf samples of both well-watered and drought-stressed plants. Eight sets of subtractive hybridizations were performed for detection of up-regulated and down-regulated genes due to the presence of the transgene and due to drought stress in both NT and transgenic plants. Sequencing analysis revealed the identity of 252 DEGs due to either the transgene and drought stress. Sequencing analysis of 170 DEGs identified genes encoding for proteins that were related to energy production, metabolism, stress defense, signaling, protein synthesis and transport, and membrane transport could play major roles in the improved drought tolerance by overexpressing ipt in creeping bentgrass.

MeSH terms

  • Adaptation, Physiological / genetics*
  • Agrostis / genetics*
  • Agrostis / physiology*
  • Cytokinins / biosynthesis*
  • Droughts*
  • Gene Expression Profiling*
  • Gene Expression Regulation, Plant*
  • Gene Library
  • Genes, Plant*
  • Plant Leaves / genetics
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Real-Time Polymerase Chain Reaction

Substances

  • Cytokinins
  • Plant Proteins
  • RNA, Messenger

Grants and funding

The authors wish to thank the OJ Noer Foundation and Rutgers Center of Turfgrass Science for funding support for this research. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.