Co-overexpression of AVP1 and OsSIZ1 in Arabidopsis substantially enhances plant tolerance to drought, salt, and heat stresses

Nardana Esmaeili,Guoxin Shen,Xiaojie Yang,Xunlu Zhu,Li Sun,Weiping Fang,Hong Zhang,Yifan Cai,Paxton Payton

doi:10.1038/s41598-019-44062-0

Abstract

Abiotic stresses such as water deficit, salt, and heat are major environmental factors that negatively affect plant growth, development, and productivity. Previous studies showed that overexpression of the Arabidopsis vacuolar H+-pyrophosphatase gene AVP1 increases salt and water deficit stress tolerance and overexpression of the rice SUMO E3 ligase gene OsSIZ1 improves heat and water deficit stress tolerance in transgenic plants. In this report, the effects of co-overexpression of AVP1 and OsSIZ1 in Arabidopsis on abiotic stress tolerance were studied. It was found that AVP1/OsSIZ1 co-overexpressing plants performed significantly better than AVP1-overexpressing plants and OsSIZ1-overexpressing plants, and produced 100% more seed than wild-type plants under single stress or multiple stress conditions. The increased stress tolerance in AVP1/OsSIZ1 co-overexpressing plants was substantially larger than the increased stress tolerance in AVP1-overexpressing plants and OsSIZ1-overexpressing plants under every abiotic stress condition tested. This research provides the proof-of-concept that crop yields might be substantially improved using this approach.

Highlights

Water deficit, salinity, and heat are major environmental factors that negatively affect every aspect of plant growth and development, leading to substantial yield losses in agriculture
We measured the concentration of Na+ and K+ ions in leaves of wild-type plants (WT) and transgenic plants under control and salt stress conditions, and we found that AVP1/OsSIZ1 co-overexpressing plants (AO) plants irrigated with saline water contained around 20% and 30% more Na+ and K+ ions than WT plants, respectively
The study by Zhou et al.[45] shows that overexpression of MdSIZ1 in Arabidopsis causes in improved growth and chlorophyll production as well as enhanced proton release to medium compared to WT, indicating that SUMO E3 ligase is involved in the up-regulation of plasma membrane (PM) H+-ATPase. In agreement with these studies, we found that AVP1/OsSIZ1 co-overexpressing plants even have higher capacity in acidifying the rhizosphere (Fig. 7A), hinting at the possibility that the improved growth and yield could be related to better absorption of nutrients, increased photo-assimilate production and sucrose mobility in AVP1/OsSIZ1 co-overexpressing plants

Summary

Introduction

Salinity, and heat are major environmental factors that negatively affect every aspect of plant growth and development, leading to substantial yield losses in agriculture. Studies with AVP1-overexpressing tomato[14] and cotton[15] showed a dramatic increase in root biomass and improved plant survival rate under drought and salt stress conditions. Lv et al reported a significant improvement in growth and photosynthetic rates of cotton plants overexpressing the H+-PPase gene from Thellungiella halophila in response to salt stress[19]. Schilling et al showed that overexpression of AVP1 increased yield and shoot biomass in barely plants grown in saline soil[28] Heat stress is another environmental stress that results in significant losses in crop production worldwide[29], and it is predicted to become even more serious in the future[30]. Efforts have been made in engineering plants for heat stress tolerance by overexpressing heat-shock protein genes or heat-shock factor genes in transgenic plants over the last 20 years[3], yet limited success was made, and so far none was applied in crops

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