Barley Vacuolar Pyrophosphatase (HVP1) Gene Confers Salinity Tolerance in Locally Adapted Wheat (Triticum aestivum)

Vacuolar H⁺-pyrophosphatase (VP1) gene is an efficient proton pump that develops a proton gradient to promote Na⁺/H⁺ antiporter activity. Thus, it plays vital role in conferring salinity tolerance in plants. This study was planned to evaluate the performance of Hordium vulgare vacuolar H⁺-pyrophosphatase (HVP1) gene in wheat (Triticum aestivum). Incorporation and expression of HVP1 gene in wheat lines under maize ubiquitin (UBI1) promoter was confirmed through antibiotic selection, polymerase chain reaction, reverse-transcription polymerase chain reaction (RT-PCR) and Southern hybridization. Seeds of transgenic wheat exhibited better germination rate compared to non-transgenic when subjected to salt stress. Augmented HVP1 expression in transgenic wheat plants improved their physiological performance compared to non-transgenic. Overexpression of HVP1 in transgenic wheat plants also promoted the agronomic performance under saline field conditions (EC 16 dS m⁻¹; SAR 40.5; pH 7.82–8.92) compared to non-transgenic. Higher values of germination rate, plant height, spike length, number of spikelets per spike, 1000 grain weight, grain yield and harvest index were observed in transgenic wheat during 2017–2018 growing season at BSRI, Pakka Anna, Faisalabad. An increase of about 29% in grain yield of transgenic wheat compared to non-transgenic in saline field conditions highlights the performance of HVP1 as an affective cation pump that promotes active transport of toxic salts in vacuoles.