Czech J. Genet. Plant Breed., 2019, 55(4):156-161 | DOI: 10.17221/134/2018-CJGPB

Overexpression of Arabidopsis H⁺-pyrophosphatase improves the growth of alfalfa under long-term salinity, drought conditions and phosphate deficiencyOriginal Paper

Jia-Hao Su^†, Tian-Hui Bai^†, Fei Wang, Ai-Ke Bao^*

State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou , P.R. China

Alfalfa planting is threatened by limited arable land, salinization, water shortage, and soil nutrient deprivation. To deal with this challenge, we previously introduced the Arabidopsis type I H⁺-pyrophosphatase gene AVP1 into alfalfa and found that transgenic lines exhibited enhanced tolerance to short-term salinity or drought. In this study, the growth performances of two transgenic lines were further investigated under long-term salinity or drought conditions, as well as under phosphate deficiency (low-Pi). Compared with wild-type (WT) plants, the transgenic alfalfa showed better growth performance with taller plants and more biomass accumulation after being treated with either long-term salinity, long-term drought, or low-Pi. Most importantly, the overexpression of AVP1 significantly increased the root dry weight and the root/shoot ratio of transgenic alfalfa. A more robust root system facilitates the transgenic alfalfa to absorb nutrients, and in turn promotes the growth of the plants. Whether being treated with low-Pi or not, transgenic plants showed higher total phosphorus concentrations by 16.5-35.5% than WT plants. This study laid a foundation for breeding alfalfa cultivars adapted to saline, arid and nutrient-deprived marginal land.

Keywords: AVP1 gene; growth performance; phosphorus nutrition; stress tolerance; transgenic alfalfa

Published: December 31, 2019  Show citation