Drought response in wheat: key genes and regulatory mechanisms controlling root system architecture and transpiration efficiency
- 1National Research Council Canada (NRC-CNRC), Canada
- 2Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada (AAFC), Canada
- 3Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
- 4National Agriculture and Food Research Organization (NARO), Japan
- 5International Center for Tropical Agriculture, Colombia
Abiotic stresses such as drought, heat, salinity and flooding threaten global food security. Crop genetic improvement with increased resilience to abiotic stresses is a critical component of crop breeding strategies. Wheat is an important cereal crop and a staple food source globally. Enhanced drought tolerance in wheat is critical for sustainable food production and global food security. Recent advances in drought tolerance research have uncovered many key genes and transcription regulators governing morpho-physiological traits. Genes controlling root architecture and stomatal development play an important role in soil moisture extraction and its retention, and therefore have been targets of molecular breeding strategies for improving drought tolerance. In this systematic review, we have summarized evidence of beneficial contributions of root and stomatal traits to plant adaptation to drought stress. Specifically, we discuss a few key genes such as DRO1 in rice and ERECTA in Arabidopsis and rice that were identified to be the enhancers of drought tolerance via regulation of root traits and transpiration efficiency. Additionally, we highlight several transcription factor families, such as ERF (ethylene response factors), DREB (dehydration responsive element binding), ZFP (zinc finger proteins), WRKY and MYB that were identified to be both positive and negative regulators of drought responses in wheat, rice, maize and/or Arabidopsis. The overall aim of this review was to provide an overview of candidate genes that have been tested as regulators of drought response in plants. The lack of a reference genome sequence for wheat and nontransgenic approaches for manipulation of gene functions in the past had impeded high-resolution interrogation of functional elements, including genes and QTLs, and their application in cultivar improvement. The recent developments in wheat genomics and reverse genetics, including the availability of a gold-standard reference genome sequence and advent genome editing technologies, are expected to aid in deciphering of the functional roles of genes and regulatory networks underlying adaptive phenological traits, and utilizing the outcomes of such studies in developing drought tolerance cultivars.
Keywords: wheat, drought, root traits, Transpiration efficiency, Transcriptional regulation, EAR motif
Received: 31 Aug 2017;
Accepted: 07 Nov 2017.
Edited by:Raju Datla, National Research Council Canada (NRC-CNRC), Canada
Reviewed by:Rupesh K. Deshmukh, Laval University, Canada
Noemi Tel Zur, Ben-Gurion University of the Negev, Beersheba, Israel
Copyright: © 2017 Kulkarni, Soolanayakanahally, Ogawa, Uga, Selvaraj and Kagale. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Sateesh Kagale, National Research Council Canada (NRC-CNRC), 110 Gymnasium Place, Ottawa, S7N 0W9, Saskatchewan, Canada, Sateesh.Kagale@nrc-cnrc.gc.ca