RETRACTED: Overexpression ofVP, a vacuolar H+-pyrophosphatase gene in wheat (Triticum aestivumL.), improves tobacco plant growth under Pi and N deprivation, high salinity, and drought

Abstract

Establishing crop cultivars with strong tolerance to P and N deprivation, high salinity, and drought is an effective way to improve crop yield and promote sustainable agriculture worldwide. A vacuolar H+-pyrophosphatase (V-H+-PPase) gene in wheat (TaVP) was functionally characterized in this study. TaVP cDNA is 2586-bp long and encodes a 775-amino-acid polypeptide that contains 10 conserved membrane-spanning domains. Transcription of TaVP was upregulated by inorganic phosphate (Pi) and N deprivation, high salinity, and drought. Transgene analysis revealed that TaVP overexpression improved plant growth under normal conditions and specifically under Pi and N deprivation stresses, high salinity, and drought. The improvement of growth of the transgenic plants was found to be closely related to elevated V-H+-PPase activities in their tonoplasts and enlarged root systems, which possibly resulted from elevated expression of auxin transport-associated genes. TaVP-overexpressing plants showed high dry mass, photosynthetic efficiencies, antioxidant enzyme activities, and P, N, and soluble carbohydrate concentrations under various growth conditions, particularly under the stress conditions. The transcription of phosphate and nitrate transporter genes was not altered in TaVP-overexpressing plants compared with the wild type, suggesting that high P and N concentrations regulated by TaVP were caused by increased root absorption area instead of alteration of Pi and NO3 − acquisition kinetics. TaVP is important in the tolerance of multiple stresses and can serve as a useful genetic resource to improve plant P- and N-use efficiencies and to increase tolerance to high salinity and drought.

Arabidopsis Type I Proton-Pumping Pyrophosphatase Expresses Strongly in Phloem, Where It Is Required for Pyrophosphate Metabolism and Photosynthate Partitioning

“…Yang et al, 2007;Bao et al, 2008;Lv et al, 2008;Pasapula et al, 2011;Arif et al, 2013;Paez-Valencia et al, 2013;Schilling et al, 2014). Some of these transgenic plants also have enhanced rhizosphere acidification capacity and nutrient use efficiencies (Yang et al, 2007;Pei et al, 2012;Undurraga et al, 2012;Paez-Valencia et al, 2013;Li et al, 2014). These phenotypes suggest that H + -PPase up-regulation elicits an increased production and mobilization of photoassimilates.…”

“…Pizzio, and K. Regmi, unpublished data). In addition to salt and drought tolerance, increased shoot and root biomass and yield, enhanced root acidification, and improved nutrient use efficiencies were also reported (Yang et al, 2007(Yang et al, , 2014Lv et al, 2008;Pasapula et al, 2011;Pei et al, 2012;Arif et al, 2013;Paez-Valencia et al, 2013;Li et al, 2014;Schilling et al, 2014;Wang et al, 2014). These phenotypes are not well explained by the traditional model of type I H + -PPases operating solely on the vacuole to energize the tonoplast (Martinoia et al, 2007).…”

Job Sharing in the Endomembrane System: Vacuolar Acidification Requires the Combined Activity of V-ATPase and V-PPase

“…35S-driven overexpression of AVP1 is a successful strategy to improve crop performance. Increased biomass, higher stress tolerance, and enhanced P solubilization are highly desirable traits that have been achieved in many crop plants including rice (Oryza sativa), barley (Hordeum vulgare), wheat (Triticum aestivum), cotton (Gossypium hirsutum), sugarcane (Saccharum officinarum) (Yang et al, 2007;Pasapula et al, 2011;Kumar et al, 2014;Li et al, 2014), and tomato (Solanum lycopersicum), for which stable expression of the transgene up to the T8 generation has been reported (Park et al, 2005;Yang et al, 2014).…”

Constitutive and Companion Cell-Specific Overexpression of AVP1, Encoding a Proton-Pumping Pyrophosphatase, Enhances Biomass Accumulation, Phloem Loading, and Long-Distance Transport

“…Overexpressing the H + -PPase AVP1 and orthologs in numerous plant species increased biomass transfer to sink organs and overall whole-plant biomass accumulation Lv et al, 2008;Gonzalez et al, 2010). It also increased salt tolerance and drought resistance (Gaxiola et al, 2001;Gao et al, 2006;Brini et al, 2007;Bao et al, 2008;Li et al, 2008Li et al, , 2010Lv et al, 2009;Pasapula et al, 2011;Schilling et al, 2014) and improved growth in nutrientlimited conditions (Yang et al, 2007;Pei et al, 2012;Paez-Valencia et al, 2013;Li et al, 2014). Consistent with improved nutrient use and uptake, plants overexpressing AVP1 acidified the rhizosphere and showed greater expression of transporters involved in nitrogen, potassium, and phosphate uptake than wild-type controls (Yang et al, 2007;Undurraga et al, 2012;Pizzio et al, 2015).…”