Overexpression of V-type H+ pyrophosphatase gene EdVP1 from Elymus dahuricus increases yield and potassium uptake of transgenic wheat under low potassium conditions

Yongbin Zhou,Qinglin Si,Zhaoshi Xu,Chengshe Wang,Mengmeng Guo,Jianhui Dong,Yan Li,Ming Chen,Xueli Qi,Youzhi Ma,Weihuan Jing,Rongbang Liu,Liancheng Li,Xianguo Cheng

doi:10.1038/s41598-020-62052-5

Abstract

Lack of potassium in soil limits crop yield. Increasing yield and conserving potassium ore requires improving K use efficiency (KUE). Many genes influence KUE in plants, but it is not clear how these genes function in the field. We identified the V-type H+-pyrophosphatase gene EdVP1 from Elymus dahurica. Gene expression analysis showed that EdVP1 was induced by low potassium stress. Protein subcellular localization analysis demonstrated that EdVP1 localized on the plasma membrane. We overexpressed EdVP1 in two wheat varieties and conducted K tolerance experiments across years. Yield per plant, grain number per spike, plant height, and K uptake of four transgenic wheat lines increased significantly compared with WT; results from two consecutive years showed that EdVP1 significantly increased yield and KUE of transgenic wheat. Pot experiments showed that transgenic plants had significantly longer shoots and roots, and higher K accumulation in shoots and roots and H+-PPase activity in shoots than WT under low K. A fluidity assay of potassium ion in EdVP1 transgenic plant roots showed that potassium ion influx and H+ outflow in transgenic plants were higher than WT. Overexpressing EdVP1 significantly improved yield and KUE of transgenic wheat and was related to higher K uptake capacity in root.

Highlights

Potassium is an essential nutrient element for plants and is involved in osmoregulation and cell extension, stomatal regulation, activation of enzymes, photosynthesis, phloem loading, and transport of assimilates and water[1], thereby promoting crop yield and quality
Analysis of the physiological mechanism proved that overexpression of EdVP1 promotes K+ influx and H+ efflux in transgenic plant roots. These results show that expression of EdVP1 can promote plant uptake of K and increase grain yield under low K stress, which indicates that EdVP1 has important application prospects for genetic improvement of K use efficiency (KUE) in crops
EdVP1 can increase the yield of transgenic wheat by increasing the number of grains per spike under low potassium conditions

Summary

Introduction

Potassium is an essential nutrient element for plants and is involved in osmoregulation and cell extension, stomatal regulation, activation of enzymes, photosynthesis, phloem loading, and transport of assimilates and water[1], thereby promoting crop yield and quality. Transcription factor AtRAP2.11 participates in the transcriptional regulation of HAK59 in response to low K conditions Overexpression of these genes can improve the ability of transgenic plants to tolerate low K stress. Up-regulation of either the Arabidopsis or Thellungiella halophila type I H+-PPase enhances growth/biomass and photosynthetic capacity in a variety of agriculturally important crops (such as Arabidopsis, maize, creeping bentgrass, and cotton) grown under normal or stressful conditions such as water scarcity and salinity stress[13,14,15,16,17]. AVP1 (type I H+-PPase gene from Arabidopsis) is believed to contribute to the establishment of electrochemical potential across the vacuole membrane, which is important for subsequent vacuolar secondary transport and ion sequestration[18]. We still do not know whether the H+-PPase gene can affect the plant’s capacity to absorb K ions in the field under low K stress conditions

Methods

Results

Conclusion