Role of pearl millet aquaporin genes in abiotic stress responseP SReddyauthorKDivyaauthorKSivasakthiauthorMTharanyaauthorALaleauthorPBhatnagar-MathurauthorJKholovaauthorK KSharmaauthorVVadezauthorPearl millet, Pennisetum glaucumL.), a crop of semi-arid tropics, has remarkable tolerance to a wide range of abiotic stresses, including high degree of genetic diversity for drought stress tolerance. To investigate the molecular mechanisms that possibly account for differences in drought tolerance, four recombinant inbred lines from a high resolution cross (HRC) were selected for their variability in transpiration rate (Tr) response to vapour pressure deficit (VPD) conditions. The expression of PgAQPs in contrasting genotypes varied during the day, generally decreasing in the afternoon regardless of the VPD conditions. However, under high VPD conditions (4.21kPa), both root and leaf tissues of the VPD-insensitive genotypes had higher transcript abundance than the VPD-sensitive genotypes. Three PIP2 subfamily genes (PIP2;1, PIP2;3 and PIP2;6) particularly PIP2;6 gene, showed an increase in transcript abundance under high VPD conditions. Transgenic tobacco plants constitutively expressing PgPIP2;6 gene were developed for functional validation studies in homozygous T2 transgenic tobacco plants. The transgenic plants showed better tolerance under drought stress, VPD and salinity compared to wild type plants as seen from biochemical, physiological and molecular studies. The transgenic plants also showed increased soluble sugar, membrane stability, reduced electrolyte leakage and other photosynthetic parameters as compared to the wild type (WT). Taken together, our studies suggest that, PgPIP2;6gene can be deployed to engineer stress tolerant transgenic crops for sustained growth and productivity under unfavourable conditions.Abiotic StressPearl MilletGenetics and Genomics2017-02Conference or Workshop Item