ORIGINAL PAPER Overexpression of a Rice Monosaccharide Transporter Gene (OsMST6) Confers Enhanced Tolerance to Drought and Salinity Stress in Arabidopsis thaliana Hossein Hosseini Monfared 1,2 & Jin Kiat Chew 3 & Parisa Azizi 4 & Gang-Ping Xue 5 & Su-Fang Ee 1 & Saeid Kadkhodaei 6 & Pouya Hedayati 1 & Ismanizan Ismail 1,3 & Zamri Zainal 1,3 Published online: 4 January 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Monosaccharide transporter (MSTs) is a large family of integral membrane proteins that plays a crucial role in cell-to-cell and long-distance distribution of sugars throughout the plant. It has long been regarded as one of the most essential components in a myriad of plant physiological functions such as carbohydrate partitioning, sugar signaling, and environmental stress response. In the present study, an in vivo functional analysis of a rice monosaccharide transporter gene, namely OsMST6, has been conducted using a transgenic approach to understand its role in plant responses to abiotic stress. Physiological traits analysis indicated that the transgenic lines had a relatively lower water loss rate, higher relative water content (1.3–2.2-fold), increased cell membrane stability (1.5–2-fold), and higher total soluble sugar content (2.8–3.5-fold) compared to the parental lines. Furthermore, the overexpression of OsMST6 was also found to enhance both drought and salt tolerance in transgenic Arabidopsis thaliana. Taken together, these results suggested that OsMST6 may be involved in the adaptation of rice plant to water stress by maintaining the water status of plant cells. This study provides insight into the function of OsMST6, which may have potential application in the generation of transgenic abiotic stress-tolerant plants. Keywords Oryza sativa . Monosaccharide transporter . Drought tolerance . Transgenic Arabidopsis Key Message • The overexpression of OsMST6 confers a higher survival rate to transgenic Arabidopsis seedlings under stress. • Transgenic Arabidopsis exhibited multiple physiological traits, which are beneficial to alleviate the adverse effect of abiotic stress. • cis-regulatory elements and co-expression analysis indicated the in- volvement of OsMST6 in the response of rice to abiotic stress. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11105-019-01186-x) contains supplementary material, which is available to authorized users. * Zamri Zainal zz@ukm.edu.my 1 Centre for Biotechnology and Functional Food, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia 2 Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran 3 Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia 4 Laboratory of Plantation Science and Technology, Institute of Plantation Studies, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 5 CSIRO Plant Industry, 306 Carmody Rd, St Lucia, QLD 4067, Australia 6 Institute of Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan 84156-83111, Iran Plant Molecular Biology Reporter (2020) 38:151–164 https://doi.org/10.1007/s11105-019-01186-x