Ectopic expression of Arabidopsis Target of Rapamycin (AtTOR) improves water-use efficiency and yield potential in rice

• Published in: Scientific reports 2017-02, Vol.7 (1), p.42835-42835, Article 42835
• Main Authors: Bakshi, Achala, Moin, Mazahar, Kumar, M. Udaya, Reddy, Aramati Bindu Madhava, Ren, Maozhi, Datla, Raju, Siddiq, E. A., Kirti, P. B.
• Format: Article
• Language: English
• Subjects: 38; 38/39; 38/77; 45/29; 45/77; 631/449/1659; 704/172/4081; Abiotic stress; Abscisic acid; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Chlorophyll; Ectopic expression; Ectopic Gene Expression; Efficiency; Gene Expression Regulation, Plant; Humanities and Social Sciences; Kinases; MTOR Associated Protein, LST8 Homolog - genetics; multidisciplinary; Oryza - genetics; Oryza - growth & development; Phosphatidylinositol 3-Kinases - genetics; Phosphatidylinositol 3-Kinases - metabolism; Plant growth; Plant Proteins - genetics; Plants, Genetically Modified - growth & development; Quantitative Trait Loci; Rapamycin; Regulatory-Associated Protein of mTOR - genetics; Science; Seed germination; Stress, Physiological; TOR protein; Transcription activation; Up-Regulation; Water; Water use
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep42835

The target of Rapamycin (TOR) present in all eukaryotes is a multifunctional protein, regulating growth, development, protein translation, ribosome biogenesis, nutrient, and energy signaling. In the present study, ectopic expression of TOR gene of Arabidopsis thaliana in a widely cultivated indica rice resulted in enhanced plant growth under water-limiting conditions conferring agronomically important water-use efficiency (WUE) trait. The AtTOR high expression lines of rice exhibited profuse tillering, increased panicle length, increased plant height, high photosynthetic efficiency, chlorophyll content and low ∆ 13 C. Δ 13 C, which is inversely related to high WUE, was as low as 17‰ in two AtTOR high expression lines. These lines were also insensitive to the ABA-mediated inhibition of seed germination. The significant upregulation of 15 stress-specific genes in high expression lines indicates their contribution to abiotic stress tolerance. The constitutive expression of AtTOR is also associated with significant transcriptional upregulation of putative TOR complex-1 components, OsRaptor and OsLST8 . Glucose-mediated transcriptional activation of AtTOR gene enhanced lateral root formation. Taken together, our findings indicate that TOR , in addition to its multiple cellular functions, also plays an important role in response to abiotic stress and potentially enhances WUE and yield related attributes.