Overexpression of OsSWEET5 in rice causes growth retardation and precocious senescence.
As a novel sugar transporter family, SWEETs play important roles in plant growth and development. Here, we characterized a SWEET gene named OsSWEET5 through its overexpression in rice. Heterologous expression assay indicated that OsSWEET5 encoded a galactose transporter in yeast. OsSWEET5-overexpressing plants displayed the phenotypes of growth retardation and precocious senescence at seedling stage. GC-MS analysis showed that the sugar levels were largely altered in the leaves of the OsSWEET5-overexpressing plants. Molecular analysis revealed that these phenotypes might be due to the transcriptional changes of the genes involved in sugar metabolism and transport. In addition, the transgenic plants showed a lower level of auxin with altered transcription of genes involved in auxin signaling and translocation pathways. However, no obvious phenotype was observed between the amiRNA-OsSWEET5 transgenic lines and WT plants, which could be a result of the functional redundancy of the galactose transporters in rice. Taken together, our findings suggest that OsSWEET5 plays a crucial role in regulating the crosstalk between sugar and auxin in rice.
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Yong
Y
Zhou
Plant Reproductive Biology, University of California Davis, Davis, California, United States of America.
Li
L
Liu
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Weifeng
W
Huang
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Meng
M
Yuan
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Fei
F
Zhou
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Xianghua
X
Li
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
Yongjun
Y
Lin
D001692:Biological Transport / Q000235:genetics; D050260:Carbohydrate Metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D042541:Intracellular Space / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development
D026901:Membrane Transport Proteins; D010940:Plant Proteins