Ectopic expression of secretory peptide PdEPF3 in Arabidopsis confers drought tolerance with reduced stomatal density

Sha Liu,Xinli Xia,Fuli Jia,Weilun Yin,Jingjing Wang,Zhiyin Jiao

doi:10.5586/asbp.3627

Abstract

Drought is one of the most prevalent environmental stresses that affect plant growth and development. Improvement in drought tolerance is associated with reduced stomatal density and higher water use efficiency (WUE). In this study, an epidermal patterning factor (EPF), PdEPF3, from a fast-growing poplar clone, NE-19 [Populus nigra × (Populus deltoides × Populus nigra)], was characterized. Quantitative reverse transcription polymerase chain reaction showed that the transcription of PdEPF3 was induced by drought. We further found that the transgenic Arabidopsis overexpressing PdEPF3 had an earlier seedling germination and longer primary roots under osmotic stress treatments, compared with the WT and mutant epf1-1. In addition, ectopic overexpression of PdEPF3 in Arabidopsis plants was able to enhance drought tolerance. This observation was associated with the reduced stomatal density of transgenic plants, which would limit transpiration and reduce water loss, consequently improving the WUE of plants. Interestingly, the reduction of stomatal density in transgenic plants overexpressing PdEPF3 did not affect their photosynthetic capacity. These results indicate that PdEPF3 could be used in transgenic breeding to enhance plant drought tolerance.

Highlights

At present, 65% of the world’s agroforestry production is affected by drought, with developing countries accounting for more than 80% of this proportion [1]
We demonstrate that the ectopic overexpression of PdEPF3 reduced the stomatal density and water loss mediated by, increasing drought tolerance
We identified a putative poplar peptide which was homologous to PdEPF1 [12], and designated this peptide as PdEPF3 (GenBank accession number MF461306)

Summary

Introduction

65% of the world’s agroforestry production is affected by drought, with developing countries accounting for more than 80% of this proportion [1]. For the sustainable development of agriculture and environment, it is important to identify key genes that enhance drought tolerance without reducing yield or biomass [2]. With the development of molecular biology and genetics, more researchers are focusing on the use of technology to improve the water use efficiency (WUE) of plants. Water use efficiency is defined as the ratio of carbon assimilation to transpiration, or the ratio of biomass production to water consumption. Compared with other engineering techniques for water saving, breeding new varieties with a high WUE and drought resistance has several advantages, such as: low investment and sustainable efficiency [3]. The most obvious and important management strategies for plants to cope with drought stress are minimizing water loss through closure of stomata and reduction in stomatal density [2].

Methods

Results

Conclusion