Enhanced disease resistance and drought tolerance in transgenic rice plants overexpressing protein elicitors from Magnaporthe oryzae

PLoS One. 2017 Apr 18;12(4):e0175734. doi: 10.1371/journal.pone.0175734. eCollection 2017.

Abstract

Exogenous application of the protein elicitors MoHrip1 and MoHrip2, which were isolated from the pathogenic fungus Magnaporthe oryzae (M. oryzae), was previously shown to induce a hypersensitive response in tobacco and to enhance resistance to rice blast. In this work, we successfully transformed rice with the mohrip1 and mohrip2 genes separately. The MoHrip1 and MoHrip2 transgenic rice plants displayed higher resistance to rice blast and stronger tolerance to drought stress than wild-type (WT) rice and the vector-control pCXUN rice. The expression of salicylic acid (SA)- and abscisic acid (ABA)-related genes was also increased, suggesting that these two elicitors may trigger SA signaling to protect the rice from damage during pathogen infection and regulate the ABA content to increase drought tolerance in transgenic rice. Trypan blue staining indicated that expressing MoHrip1 and MoHrip2 in rice plants inhibited hyphal growth of the rice blast fungus. Relative water content (RWC), water usage efficiency (WUE) and water loss rate (WLR) were measured to confirm the high capacity for water retention in transgenic rice. The MoHrip1 and MoHrip2 transgenic rice also exhibited enhanced agronomic traits such as increased plant height and tiller number.

MeSH terms

  • Abscisic Acid / genetics
  • Acclimatization
  • Disease Resistance
  • Droughts
  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Plant
  • Magnaporthe / genetics*
  • Oryza / genetics*
  • Oryza / immunology*
  • Plant Diseases / genetics*
  • Plant Diseases / immunology
  • Plant Diseases / microbiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified / genetics*
  • Plants, Genetically Modified / physiology
  • Salicylic Acid / metabolism
  • Up-Regulation

Substances

  • Fungal Proteins
  • Plant Proteins
  • Abscisic Acid
  • Salicylic Acid

Grants and funding

We would like to thank Professor Songbiao Chen in Fujian Academy of Agricultural Sciences for cultivating transgenic rice. This work was supported by grants from the National Hi-Tech Research and Development Program of China (‘‘863’’ Projects, grant nos. 2012AA101504).