Expression patterns of members of the ethylene signaling-related gene families in response to dehydration stresses in cassava

PLoS One. 2017 May 23;12(5):e0177621. doi: 10.1371/journal.pone.0177621. eCollection 2017.

Abstract

Drought is the one of the most important environment stresses that restricts crop yield worldwide. Cassava (Manihot esculenta Crantz) is an important food and energy crop that has many desirable traits such as drought, heat and low nutrients tolerance. However, the mechanisms underlying drought tolerance in cassava are unclear. Ethylene signaling pathway, from the upstream receptors to the downstream transcription factors, plays important roles in environmental stress responses during plant growth and development. In this study, we used bioinformatics approaches to identify and characterize candidate Manihot esculenta ethylene receptor genes and transcription factor genes. Using computational methods, we localized these genes on cassava chromosomes, constructed phylogenetic trees and identified stress-responsive cis-elements within their 5' upstream regions. Additionally, we measured the trehalose and proline contents in cassava fresh leaves after drought, osmotic, and salt stress treatments, and then it was found that the regulation patterns of contents of proline and trehalose in response to various dehydration stresses were differential, or even the opposite, which shows that plant may take different coping strategies to deal with different stresses, when stresses come. Furthermore, expression profiles of these genes in different organs and tissues under non-stress and abiotic stress were investigated through quantitative real-time PCR (qRT-PCR) analyses in cassava. Expression profiles exhibited clear differences among different tissues under non-stress and various dehydration stress conditions. We found that the leaf and tuberous root tissues had the greatest and least responses, respectively, to drought stress through the ethylene signaling pathway in cassava. Moreover, tuber and root tissues had the greatest and least reponses to osmotic and salt stresses through ethylene signaling in cassava, respectively. These results show that these plant tissues had differential expression levels of genes involved in ethylene signaling in response to the stresses tested. Moreover, after several gene duplication events, the spatiotemporally differential expression pattern of homologous genes in response to abiotic and biotic stresses may imply their functional diversity as a mechanism for adapting to the environment. Our data provide a framework for further research on the molecular mechanisms of cassava resistance to drought stress and provide a foundation for breeding drought-resistant new cultivars.

MeSH terms

  • Computer Simulation
  • Dehydration / genetics*
  • Dehydration / metabolism*
  • Ethylenes / metabolism
  • Gene Expression Profiling
  • Manihot / genetics*
  • Manihot / metabolism*
  • Phylogeny
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Proline / metabolism
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Stress, Physiological / genetics*
  • Stress, Physiological / physiology*
  • Time Factors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Trehalose / metabolism

Substances

  • Ethylenes
  • Plant Proteins
  • Transcription Factors
  • ethylene
  • Proline
  • Trehalose

Grants and funding

This study was supported by the National Nature Science Foundation of China (31201603, 31501043) to RJF; the National High Technology Research and Development Program of China (863 Programme; no. 2012AA101204-2) to MP; the Major Science and Technology program of Hainan (ZDZX2013023-1) to MP; the Hainan Natural Science Foundation (312050, 312051) to RJF and JYW; and the Graduate Outstanding Dissertation Cultivation Plan of Hainan University (15) to MYR.