Overexpressing of OsAMT1-3, a High Affinity Ammonium Transporter Gene, Modifies Rice Growth and Carbon-Nitrogen Metabolic Status

International Journal of Molecular Sciences

Aili Bao²  Zhijun Liang²  Zhuqing Zhao²  Hongmei Cai¹ 

[1] Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Microelement Research Center, Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China;

关键词: AMT1-3;    carbon-nitrogen metabolism;    ¹⁵N tracer;    overexpressing;    rice;   

DOI  :  10.3390/ijms16059037

来源: mdpi

【 摘 要 】

AMT1-3 encodes the high affinity NH₄⁺ transporter in rice roots and is predominantly expressed under nitrogen starvation. In order to evaluate the effect of AMT1-3 gene on rice growth, nitrogen absorption and metabolism, we generated AMT1-3-overexpressing plants and analyzed the growth phenotype, yield, carbon and nitrogen metabolic status, and gene expression profiles. Although AMT1-3 mRNA accumulated in transgenic plants, these plants displayed significant decreases in growth when compared to the wild-type plants. The nitrogen uptake assay using a ¹⁵N tracer revealed poor nitrogen uptake ability in AMT1-3-overexpressing plants. We found significant decreases in AMT1-3-overexpressing plant leaf carbon and nitrogen content accompanied with a higher leaf C/N ratio. Significant changes in soluble proteins and carbohydrates were also observed in AMT1-3-overexpressing plants. In addition, metabolite profile analysis demonstrated significant changes in individual sugars, organic acids and free amino acids. Gene expression analysis revealed distinct expression patterns of genes that participate in carbon and nitrogen metabolism. Additionally, the correlation between the metabolites and gene expression patterns was consistent in AMT1-3-overexpressing plants under both low and high nitrogen growth conditions. Therefore, we hypothesized that the carbon and nitrogen metabolic imbalance caused by AMT1-3 overexpressing attributed to the poor growth and yield of transgenic plants.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.