Functional characterization of OsmiR396a in rice (Oryza sativa L.)
miR396 is a conservative microRNA family, which has been shown to be important for plant growth and development. To investigate the functions of miR396 in rice (Oryza sativa L.), we carried out a study on OsmiR396a. We found that OsmiR396a was expressed in various tissues with highest transcriptional level in leaves. Bioinformatic prediction suggested that OsmiR396a targets nine Growth Regulating Factor(GRF) genes, of which four (OsGRF1/2/6/8) were significantly down regulated by overexpression of OsmiR396a (aOE). aOE severely suppressed cell proliferation, leading to dwarf plants with smaller leaves. aOE also resulted in abnormal panicles and spikelets, especially a large proportion of rare conjoined-twin florets. Consistent with these defects, some related genes, including H4-2 and OsRAN2 (involved in cell division), FZP and LAX1 (controlling inflorescence architecture) and various floral organ identity genes (involved in floral development), exhibited significantly altered expressional levels in the aOE plants. Our findings further demonstrated the functional conservation of miR396 across dicot and monocot plants and suggested that OsmiR396a functions mainly by targeting OsGRF genes and indirectly regulating many downstream genes in rice.
KeywordsRice OsmiR396a Overexpression Functional characterization
We thank Dr. Tao Lan, Dr. Mo Wang, Dr. Xiaofang Xie, Junjie Lin, Chunfen Lai, Binqing Lin, Qin Lin, Huan Chen and Owie Swithin Omosuwa for their help in the experiments. This work was supported by National Natural Science Foundation of China (Project No.: 31301003).
ZD: Conceived and designed the experiments, performed the experiments, analyzed the data, contributed regents/materials/analysis tools and wrote the paper. WW: Conceived and designed the experiments, analyzed the data, contributed regents/materials/analysis tools and wrote the paper. MY: Performed the experiments, analyzed the data and wrote the paper. SB: Analyzed the data. YD: Contributed regents/materials/analysis tools. LZ: Performed the experiments.
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Conflict of interest
The authors declare no potential competing interests.
- Duan Y, Xing Z, Diao Z, Xu W, Li S, Du X, Wu G, Wang C, Lan T, Meng Z, Liu H, Wang F, Wu W, Xue Y (2012) Characterization of Osmads6-5, a null allele, reveals that OsMADS6 is a critical regulator for early flower development in rice (Oryza sativa L.). Plant Mol Biol 80(4–5):429–442CrossRefPubMedGoogle Scholar
- Tobina H, Uozu S, Matsuoka M, Kitano H, Hattori K (2003) Gene expression pattern of cell division/elongation factors in rice dwarf mutants. In: Khush GS, Brar DS, Hardy B (eds) In advances in rice genetics. International Rice Research Institute, Manila, pp 470–472Google Scholar
- Zhou S, Wang Y, Li W, Zhao Z, Ren Y, Wang Y, Gu S, Lin Q, Wang D, Jiang L, Su N, Zhang X, Liu L, Cheng Z, Lei C, Wang J, Guo X, Wu F, Ikehashi H, Wang H, Wan J (2011) Pollen semi-sterility1 encodes a kinesin-1-like protein important for male meiosis, anther dehiscence, and fertility in rice. Plant Cell 23(1):111–129CrossRefPubMedPubMedCentralGoogle Scholar