Up-regulation of a H ⁺ -pyrophosphatase (H ⁺ -PPase) as a strategy to engineer drought-resistant crop plants

Abstract

Engineering drought -resistant crop plants is a critically important objective. Overexpression of the vacuolar H ؉ -pyrophosphatase (H ؉ -PPase) AVP1 in the model plant Arabidopsis thaliana results in enhanced performance under soil water deficits. Recent work demonstrates that AVP1 plays an important role in root development through the facilitation of auxin fluxes. With the objective of improving crop performance, we expressed AVP1 in a commercial cultivar of tomato. This approach resulted in (i) greater pyrophosphate-driven cation transport into root vacuolar fractions, (ii) increased root biomass, and (iii) enhanced recovery of plants from an episode of soil water deficit stress. More robust root systems allowed transgenic tomato plants to take up greater amounts of water during the imposed water deficit stress, resulting in a more favorable plant water status and less injury. This study documents a general strategy for improving drought resistance of crops.root development ͉ biotechnology ͉ water deficit stress ͉ tomato

Optimization of regeneration and transformation parameters in tomato and improvement of its salinity and drought tolerance

“…Furthermore, transgenic tomato plants overexpressing the pyrophosphatase gene exhibited a more robust root system compared to wild type and TNHX1 tomato plants ( Figure 3c and d); such phenotype was previously described by Park et al (2005). This holds true for tomato plants grown in pots as well as those grown continuously in a hydroponic culture during a three months period.…”

“…The vacuolar sodium antiporter and pyrophosphatase genes from diverse species were successfully overexpressed and shown to confer salinity and drought tolerance in many model and cultivated plants (Park et al, 2005;Zhang and Blumwald, 2001;Jia et al, 2002;Lee et al, 2003). In the present study, we introduced two wheat genes encoding these vacuolar proteins and evaluated their potential to confer salinity tolerance in tomato.…”

“…Addressing these problems by using classical breeding programmes remains a challenge for breeders since tolerance to salinity is a very complex character involving many genes with small effects (Cuartero et al, 2006). Fortunately, with the advent of genetic engineering tools it became possible to introduce a single gene in plants to enhance abiotic stress tolerance, at least to some extent, without adverse effects on the final product quality (Park et al, 2005;Zhang and Blumwald, 2001;Jia et al, 2002;Lee et al, 2003). The establishment of an efficient in vitro regeneration and transformation protocol is a prerequisite for the genetic improvement of tomato.…”

H+‐pyrophosphatase IbVP1 promotes efficient iron use in sweet potato [Ipomoea batatas (L.) Lam.]

“…Under stressful conditions, up‐regulation of enzyme expression enables plant cells to use PPi as an energy source and maintain membrane integrity and intracellular transport via hydrolysis‐mediated ion transport (Gaxiola et al ., 2016; Greenway and Gibbs, 2003; Stitt, 1998). Increased abiotic stress tolerance and enhanced growth performance in Pi or nitrogen deficiency were observed during H + ‐PPase overexpression in Arabidopsis (Gaxiola et al ., 2001), tomato(Dong et al ., 2011; Park et al ., 2005; Yang et al ., 2007), tobacco (Khoudi et al ., 2012), rice (Zhang et al ., 2011; Zhao et al ., 2006), maize (Li et al ., 2008), lettuce (Paez‐Valencia et al ., 2013) and cotton (Lv et al ., 2009; Pasapula et al ., 2011). Nevertheless, the role of H + ‐PPase‐induced Fe uptake is unknown.…”

Elymus dahuricus H+-PPase EdVP1 enhances potassium uptake and utilization of wheat through the development of root system

“…The size of the root system, the physiology of uptake and the ability of plants to increase K solubility in the rhizosphere by exudation of organic compounds are considered as mechanisms of uptake efficiency Rengel and Damon, 2008). In recent years, H + -PPase gene cloned from Arabidopsis and Hordeum vulgare have been proved to play an important role in improving the salt drougt tolerance of transgenic plants (Liu et al, 2005;Park et al, 2005). However, there is little research involving the function of Elymus dahuricus H + -PPase (EdVP1) in the transgenic plants.…”