Future-Proofing Potato for Drought and Heat Tolerance by Overexpression of Hexokinase and SP6A.

Günter G Lehretz,Nitsan Lugassi,Uwe Sonnewald,Sophia Sonnewald,David Granot

doi:10.3389/fpls.2020.614534

Günter G Lehretz, Nitsan Lugassi + Show 3 more

Open Access

https://doi.org/10.3389/fpls.2020.614534

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Abstract

Crop yield is largely affected by global climate change. Especially periods of heat and drought limit crop productivity worldwide. According to current models of future climate scenarios, heatwaves and periods of drought are likely to increase. Potato, as an important food crop of temperate latitudes, is very sensitive to heat and drought which impact tuber yield and quality. To improve abiotic stress resilience of potato plants, we aimed at co-expressing hexokinase 1 from Arabidopsis thaliana (AtHXK1) in guard cells and SELF-PRUNING 6A (SP6A) using the leaf/stem-specific StLS1 promoter in order to increase water use efficiency as well as tuberization under drought and heat stress. Guard cell-specific expression of AtHXK1 decreased stomatal conductance and improved water use efficiency of transgenic potato plants as has been shown for other crop plants. Additionally, co-expression with the FT-homolog SP6A stimulated tuberization and improved assimilate allocation to developing tubers under control as well as under single and combined drought and heat stress conditions. Thus, co-expression of both proteins provides a novel strategy to improve abiotic stress tolerance of potato plants.

Highlights

Global climate change has become a huge threat for food security worldwide (Birch et al, 2012; Mittler et al, 2012; Fahad et al, 2017; George et al, 2017; Lamaoui et al, 2018; Dahal et al, 2019)
We provide a novel strategy to adopt potato plants to withstand expected climate changes and help to secure future carbohydrate food production while saving water resources at the same time
In previous studies it has been shown that guard cell-specific expression of AtHXK1 improves water use efficiency (WUE) of several plant species (Kelly et al, 2013, 2017; Lugassi et al, 2015)

Summary

Introduction

Global climate change has become a huge threat for food security worldwide (Birch et al, 2012; Mittler et al, 2012; Fahad et al, 2017; George et al, 2017; Lamaoui et al, 2018; Dahal et al, 2019). Potato plants are very sensitive to elevated temperatures (Lafta and Lorenzen, 1995; Levy and Veilleux, 2007; Hastilestari et al, 2018; Trapero-Mozos et al, 2018), and drought susceptible (Deblonde and Ledent, 2001). They originate from relatively cool regions in the Andes of South America and produce starchy storage organs, the tubers, which form from underground stems, the stolons. This process has been described previously (Hannapel et al, 2017), and is amongst various other regulators mainly

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