In the present study, we illustrate the strategy and protocol required to generate rice transgenics over-expressing the 21-nt form of Osa-miR820. The miR exists in two size variants of 21-nt and 24-nt so the natural precursor cannot be employed for the purpose of miR over-expression as the cellular machinery can process both size variants thereby masking the role of PTGS regulation. Hence, we adopted the artificial miR technology to specifically over-express the 21-nt species in the transgenics. During the course of experiments it was observed that the amiR constructs probably interfered with the regeneration of the transformed callus, necessitating protocol modifications. The results indicate the successful over-expression of the 21-nt miR species. These plants can serve as a useful source for the functional dissection of the role played by the 21-nt Osa-miR820 species. They will also be valuable in highlighting the importance for the existence of a dual mode of miR mediated target regulation.
Birch, R.G. (1997) Plant Transformation: Problems and Strategies for Practical Application. Annual Review of Plant Biology, 48, 297-326. http://dx.doi.org/10.1146/annurev.arplant.48.1.297
Hansen, G. and Wright, M.S. (1999) Recent Advances in the Transformation of Plants. Trends in Plant Science, 4, 226-231. http://dx.doi.org/10.1016/S1360-1385(99)01412-0
Zaidi, M., Narayanan, M., Sardana, R., Taga, I., Postel, S., Johns, R., McNulty, M., Mottiar, Y., Mao, J. and Loit, E. (2006) Optimizing Tissue Culture Media for Efficient Transformation of Different Indica Rice Genotypes. Agronomy Research, 4, 563-575.
Hiei, Y. and Komari, T. (2006) Improved Protocols for Transformation of Indica Rice Mediated by Agrobacterium tumefaciens. Plant Cell, Tissue and Organ Culture, 85, 271-283. http://dx.doi.org/10.1007/s11240-005-9069-8
Lin, Y.J. and Zhang, Q. (2005) Optimising the Tissue Culture Conditions for High Efficiency Transformation of Indica Rice. Plant Cell Reports, 23, 540-547. http://dx.doi.org/10.1007/s00299-004-0843-6
Mohanty, A., Kathuria, H., Ferjani, A., Sakamoto, A., Mohanty, P., Murata, N. and Tyagi, A. (2002) Transgenics of an Elite Indica Rice Variety Pusa Basmati 1 Harbouring the codA Gene Are Highly Tolerant to Salt Stress. Theoretical and Applied Genetics, 106, 51-57.
Sah, S., Kaur, A., Kaur, G. and Cheema, G. (2014) Genetic Transformation of Rice: Problems, Progress and Prospects. Journal of Rice Research, 3, 2.
Ge, X., Chu, Z., Lin, Y. and Wang, S. (2006) A Tissue Culture System for Different Germplasms of Indica Rice. Plant Cell Reports, 25, 392-402. http://dx.doi.org/10.1007/s00299-005-0100-7
Kant, P., Kant, S., Jain, R. and Chaudhury, V. (2007) Agrobacterium-Mediated High Frequency Transformation in Dwarf Recalcitrant Rice Cultivars. Biologia Plantarum, 51, 61-68. http://dx.doi.org/10.1007/s10535-007-0012-1
Patel, M., Dewey, R. and Qu, R. (2013) Enhancing Agrobacterium tumefaciens-Mediated Transformation Efficiency of Perennial Ryegrass and Rice Using Heat and High Maltose Treatments during Bacterial Infection. Plant Cell, Tissue and Organ Culture, 114, 19-29. http://dx.doi.org/10.1007/s11240-013-0301-7
Sahoo, K.K., Tripathi, A.K., Pareek, A., Sopory, S.K. and Singla-Pareek, S.L. (2011) An Improved Protocol for Efficient Transformation and Regeneration of Diverse Indica Rice Cultivars. Plant Methods, 7, 49. http://dx.doi.org/10.1186/1746-4811-7-49
Shri, M., Rai, A., Verma, P., Misra, P., Dubey, S., Kumar, S., Verma, S., Gautam, N., Tripathi, R., Trivedi, P. and Chakrabarty, D. (2013) An Improved Agrobacterium-Mediated Transformation of Recalcitrant Indica Rice (Oryza sativa L.) Cultivars. Protoplasma, 250, 631-636. http://dx.doi.org/10.1007/s00709-012-0439-x
Tripathi, R., Bisht, H. and Singh, R. (2010) Effect of Acetosyringone and Callus Age on Transformation for Scutellum-Derived Callus of Rice. International Journal of Pharma and Bio Sciences, 4, 163-170.
Lee, Y., Kim, M., Han, J., Yeom, K.-H., Lee, S., Baek, S.H. and Kim, V.N. (2004) MicroRNA Genes Are Transcribed by RNA Polymerase II. The EMBO Journal, 23, 4051-4060. http://dx.doi.org/10.1038/sj.emboj.7600385
Rogers, K. and Chen, X. (2013) Biogenesis, Turnover, and Mode of Action of Plant microRNAs. The Plant Cell, 25, 2383-2399. http://dx.doi.org/10.1105/tpc.113.113159
Voinnet, O. (2009) Origin, Biogenesis, and Activity of Plant MicroRNAs. Cell, 136, 669-687. http://dx.doi.org/10.1016/j.cell.2009.01.046
Cuperus, J.T., Carbonell, A., Fahlgren, N., Garcia-Ruiz, H., Burke, R.T., Takeda, A., Sullivan, C.M., Gilbert, S.D., Montgomery, T.A. and Carrington, J.C. (2010) Unique Functionality of 22-nt miRNAs in Triggering RDR6-Dependent siRNA Biogenesis from Target Transcripts in Arabidopsis. Nature Structural & Molecular Biology, 17, 997-1003. http://dx.doi.org/10.1038/nsmb.1866
Wu, L., Zhou, H., Zhang, Q., Zhang, J., Ni, F., Liu, C. and Qi, Y. (2010) DNA Methylation Mediated by a microRNA Pathway. Molecular Cell, 38, 465-475. http://dx.doi.org/10.1016/j.molcel.2010.03.008
Jones-Rhoades, M.W. and Bartel, D.P. (2004) Computational Identification of Plant microRNAs and Their Targets, including a Stress-Induced miRNA. Molecular Cell, 14, 787-799. http://dx.doi.org/10.1016/j.molcel.2004.05.027
Mittal, D., Mukherjee, S.K., Vasudevan, M. and Mishra, N.S. (2013) Identification of Tissue-Preferential Expression Patterns of Rice miRNAs. Journal of Cellular Biochemistry, 114, 2071-2081. http://dx.doi.org/10.1002/jcb.24552
Sanan-Mishra, N., Kumar, V., Sopory, S.K. and Mukherjee, S.K. (2009) Cloning and Validation of Novel miRNA from Basmati Rice Indicates Cross Talk between Abiotic and Biotic Stresses. Molecular Genetics and Genomics, 282, 463-474. http://dx.doi.org/10.1007/s00438-009-0478-y
Sunkar, R., Chinnusamy, V., Zhu, J. and Zhu, J.K. (2007) Small RNAs as Big Players in Plant Abiotic Stress Responses and Nutrient Deprivation. Trends in Plant Sciences, 12, 301-309. http://dx.doi.org/10.1016/j.tplants.2007.05.001
Luo, Y.-C., Zhou, H., Li, Y., Chen, J.-Y., Yang, J.-H., Chen, Y.-Q. and Qu, L.-H. (2006) Rice Embryogenic Calli Express a Unique Set of microRNAs, Suggesting Regulatory Roles of microRNAs in Plant Post-Embryogenic Development. FEBS Letters, 580, 5111-5116. http://dx.doi.org/10.1016/j.febslet.2006.08.046
Nosaka, M., Ishiwata, A., Shimizu-Sato, S., Ono, A., Ishimoto, K., Noda, Y. and Sato, Y. (2013) The Copy Number of Rice CACTA DNA Transposons Carrying MIR820 Does Not Correlate with MIR820 Expression. Plant Signaling & Behavior, 8, Article ID: e25169. http://dx.doi.org/10.4161/psb.25169
Nosaka, M., Ono, A., Ishiwata, A., Shimizu-Sato, S., Ishimoto, K., Noda, Y. and Sato, Y. (2013) Expression of the Rice microRNA miR820 Is Associated with Epigenetic Modifications at Its Own Locus. Genes & Genetic Systems, 88, 105-112. http://dx.doi.org/10.1266/ggs.88.105
Jeong, D.-H., Park, S., Zhai, J., Gurazada, S.G.R., De Paoli, E., Meyers, B.C. and Green, P.J. (2011) Massive Analysis of Rice Small RNAs: Mechanistic Implications of Regulated microRNAs and Variants for Differential Target RNA Cleavage. The Plant Cell, 23, 4185-4207. http://dx.doi.org/10.1105/tpc.111.089045
Sharma, N., Tripathi, A. and Sanan-Mishra, N. (2015) Profiling the Expression Domains of a Rice-Specific microRNA under Stress. Frontiers in Plant Science, 6, 333. http://dx.doi.org/10.3389/fpls.2015.00333
Sharma, D., Tiwari, M., Lakhwani, D., Tripathi, R.D. and Trivedi, P.K. (2015) Differential Expression of microRNAs by Arsenate and Arsenite Stress in Natural Accessions of Rice. Metallomics, 7, 174-187. http://dx.doi.org/10.1039/C4MT00264D
Warthmann, N., Chen, H., Ossowski, S., Weigel, D. and Hervé, P. (2008) Highly Specific Gene Silencing by Artificial miRNAs in Rice. PLoS ONE, 3, e1829.
Karjee, S., Islam, M. and Mukherjee, S. (2008) Screening and Identification of Virus-Encoded RNA Silencing Suppressors. In: Barik, S., Ed., RNAi, Humana Press, New York, 187-203.
Murray, M.G. and Thompson, W.F. (1980) Rapid Isolation of High Molecular Weight Plant DNA. Nucleic Acids Research, 8, 4321-4325. http://dx.doi.org/10.1093/nar/8.19.4321
Khraiwesh, B., Ossowski, S., Weigel, D., Reski, R. and Frank, W. (2008) Specific Gene Silencing by Artificial microRNAs in Physcomitrella patens: An Alternative to Targeted Gene Knockouts. Plant Physiology, 148, 684-693. http://dx.doi.org/10.1104/pp.108.128025
Schwab, R., Ossowski, S., Riester, M., Warthmann, N. and Weigel, D. (2006) Highly Specific Gene Silencing by Artificial microRNAs in Arabidopsis. The Plant Cell, 18, 1121-1133. http://dx.doi.org/10.1105/tpc.105.039834
Hiei, Y., Ohta, S., Komari, T. and Kumashiro, T. (1994) Efficient Transformation of Rice (Oryza sativa L.) Mediated by Agrobacterium and Sequence Analysis of the Boundaries of the T-DNA. The Plant Journal, 6, 271-282. http://dx.doi.org/10.1046/j.1365-313X.1994.6020271.x
Niroula, R., Sah, B., Bimb, H. and Nayak, S. (2007) Effect of Genotype and Culture Media on Callus Induction and Plant Regeneration from Matured Rice Grain Culture. Journal of the Institute of Agriculture and Animal Science, 26, 21-26.
Hood, E., Gelvin, S., Melchers, L. and Hoekema, A. (1993) New Agrobacterium Helper Plasmids for Gene Transfer to Plants. Transgenic Research, 2, 208-218. http://dx.doi.org/10.1007/BF01977351
Nanasato, Y., Konagaya, K.-I., Okuzaki, A., Tsuda, M. and Tabei, Y. (2011) Agrobacterium-Mediated Transformation of Kabocha Squash (Cucurbita moschata Duch) Induced by Wounding with Aluminum Borate Whiskers. Plant Cell Reports, 30, 1455-1464. http://dx.doi.org/10.1007/s00299-011-1054-6
Nanasato, Y., Konagaya, K.-I., Okuzaki, A., Tsuda, M. and Tabei, Y. (2013) Improvement of Agrobacterium-Mediated Transformation of Cucumber (Cucumis sativus L.) by Combination of Vacuum Infiltration and Co-Cultivation on Filter Paper Wicks. Plant Biotechnology Reports, 7, 267-276. http://dx.doi.org/10.1007/s11816-012-0260-1
Jain, R.K., Davey, M.R., Cocking, E.C. and Wu, R. (1997) Carbohydrate and Osmotic Requirements for High-Frequency Plant Regeneration from Protoplast-Derived Colonies of Indica and Japonica Rice Varieties. Journal of Experimental Botany, 48, 751-758. http://dx.doi.org/10.1093/jxb/48.3.751
Feng, X., Zhao, P., Hao, J., Hu, J., Kang, D. and Wang, H. (2011) Effects of Sorbitol on Expression of Genes Involved in Regeneration of Upland Rice (Oryza sativa L.). Plant Cell, Tissue and Organ Culture, 106, 455-463. http://dx.doi.org/10.1007/s11240-011-9943-5
Geng, P., La, H., Wang, H. and Stevens, E.J. (2008) Effect of Sorbitol Concentration on Regeneration of Embryogenic Calli in Upland Rice Varieties (Oryza sativa L.). Plant Cell, Tissue and Organ Culture, 92, 303-313. http://dx.doi.org/10.1007/s11240-007-9321-5
Steinitz, B. (1999) Sugar Alcohols Display Nonosmotic Roles in Regulating Morphogenesis and Metabolism in Plants That Do Not Produce Polyols as Primary Photosynthetic Products. Journal of Plant Physiology, 155, 1-8. http://dx.doi.org/10.1016/S0176-1617(99)80133-3
Azhakanandam, K., McCabe, M.S., Power, J.B., Lowe, K.C., Cocking, E.C. and Davey, M.R. (2000) T-DNA Transfer, Integration, Expression and Inheritance in Rice: Effects of Plant Genotype and Agrobacterium Super-Virulence. Journal of Plant Physiology, 157, 429-439. http://dx.doi.org/10.1016/S0176-1617(00)80028-0
Khanna, H.K. and Raina, S.K. (1999) Agrobacterium-Mediated Transformation of Indica Rice Cultivars Using Binary and Superbinary Vectors. Functional Plant Biology, 26, 311-324. http://dx.doi.org/10.1071/pp98160
Zhang, J., Xu, R.J., Elliott, M.C. and Chen, D.F. (1997) Agrobacterium-Mediated Transformation of Elite Indica and Japonica Rice Cultivars. Molecular Biotechnology, 8, 223-231. http://dx.doi.org/10.1007/BF02760776