西亚试剂优势供应上万种化学试剂产品，欢迎各位新老客户咨询、选购！
中国
联系我们
联系方式：400-990-3999 / 邮箱：sales@xiyashiji.com
西亚试剂 —— 品质可靠，值得信赖
Expression analysis and functional characterization of the monosaccharide transporters, OsTMTs, involving vacuolar sugar transport in rice (Oryza sativa)
Jung-Il Cho 1 , Bo Burla 2,3 , Dae-Woo Lee 1 , Nayeon Ryoo 1 , Soon-Kwan Hong 4 , Hyun-Bi Kim 1 , Joon-Seob Eom 1 , Sang-Bong Choi 5 , Man-Ho Cho 1 , Seong Hee Bhoo 1 , Tae-Ryong Hahn 1 , H. Ekkehard Neuhaus 6 , Enrico Martinoia 2,3 and Jong-Seong Jeon 1,7
1 Graduate School of Biotechnology and Plant Metabolism Research Center, Kyung Hee University, Yongin 446-701, Korea ; 2 Institute of Plant Biology, University Zurich, CH–8008 Zurich, Switzerland ; 3 POSTECH-UZH Global Research Laboratory, Division of Molecular Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea ; 4 Department of Plant Biotechnology, Kangwon National University, Chuncheon 200-701, Korea ; 5 Division of Bioscience and Bioinformatics, Myongji University, Yongin 449-728, Korea ; 6 Plant Physiology, University of Kaiserslautern, D–67653 Kaiserslautern, Germany ; 7 Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
ABSTRACT
In Arabidopsis, the compartmentation of sugars into vacuoles is known to be facilitated by sugar transporters. However, vacuolar sugar transporters have not been studied in detail in other plant species.
To characterize the rice (Oryza sativa) tonoplast monosaccharide transporters, OsTMT1 and OsTMT2, we analysed their subcellular localization using green fluorescent protein (GFP) and expression patterns using reverse-transcription polymerase chain reaction (RT-PCR), performed histochemical β-glucuronidase (GUS) assay and in situ hybridization analysis, and assessed sugar transport ability using isolated vacuoles.
Expression of OsTMT–GFP fusion protein in rice and Arabidopsis revealed that the OsTMTs localize at the tonoplast. Analyses of OsTMT promoter-GUS transgenic rice indicated that OsTMT1 and OsTMT2 are highly expressed in bundle sheath cells, and in vascular parenchyma and companion cells in leaves, respectively. Both genes were found to be preferentially expressed in the vascular tissues of roots, the palea/lemma of spikelets, and in the main vascular tissues and nucellar projections on the dorsal side of the seed coats. Glucose uptake studies using vacuoles isolated from transgenic mutant Arabidopsis (tmt1-2-3) expressing OsTMT1 demonstrated that OsTMTs are capable of transporting glucose into vacuoles.
Based on expression analysis and functional characterization, our present findings suggest that the OsTMTs play a role in vacuolar glucose storage in rice.
