caa a22 4500 463171713 CHVBK 20180406164815.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s00344-006-0046-1 doi (NATIONALLICENCE)springer-10.1007/s00344-006-0046-1 A Crucial Role for Cytokinins in Pea ABR17-mediated Enhanced Germination and Early Seedling Growth of Arabidopsis thaliana under Saline and Low-temperature Stresses [Elektronische Daten] [Sanjeeva Srivastava, R. Emery, Muhammad Rahman, Nat Kav] The role of cytokinins (CKs) in mediating the previously observed ABR17-mediated enhancement of germination of Arabidopsis thaliana under salinity and low-temperature stresses has been evaluated. We determined the endogenous concentrations of CK in the three transgenic and wild-type seedlings, which indicated that the transgenic seedlings had higher endogenous concentrations of CK. Furthermore, the relative levels of expression of ABR17 cDNA and the primary CK response gene, ARR5, were evaluated in the transgenic and wild-type seedlings by quantitative real-time polymerase chain reaction (RT-PCR). Our results indicated that two of the three independently derived transgenic plants possessed higher levels of ABR17 transcripts, which correlated well with increased ARR5 expression, further supporting a possible role for CK in mediating the observed phenomenon. In addition, the exogenous application of various CKs on the germination of wild-type A. thaliana under these abiotic stress conditions enhanced its germination. Finally, the ribonuclease (RNase) activity of the pea ABR17 protein was also demonstrated after expression of its cDNA in Escherichia coli, purification of the recombinant protein, and in vitro RNase assays. Our findings are discussed within the context of ABR17-mediated enhancement of endogenous CK concentrations, the involvement of CKs in germination under abiotic stress, as well as the role of the RNase activity of ABR17 protein in mediating the observed effects. Springer Science+Business Media, Inc., 2007 Arabidopsis nationallicence ABR17 nationallicence AtARR5 nationallicence Cytokinin nationallicence Pathogenesis-related PR 10 nationallicence Ribonuclease nationallicence tRNA nationallicence Srivastava Sanjeeva Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut Emery R. Department of Biology, Trent University, K9J 7B8, Peterborough, Ontario, Canada aut Rahman Muhammad Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut Kav Nat Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut Journal of Plant Growth Regulation Springer-Verlag; www.springer-ny.com 26/1(2007-03-01), 26-37 0721-7595 26:1<26 2007 26 344 https://doi.org/10.1007/s00344-006-0046-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00344-006-0046-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Srivastava Sanjeeva Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut NATIONALLICENCE 700 1- Emery R. Department of Biology, Trent University, K9J 7B8, Peterborough, Ontario, Canada aut NATIONALLICENCE 700 1- Rahman Muhammad Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut NATIONALLICENCE 700 1- Kav Nat Department of Agricultural, Food and Nutritional Science, University of Alberta, T6G 2P5, Edmonton Alberta, Canada aut NATIONALLICENCE 773 0- Journal of Plant Growth Regulation Springer-Verlag; www.springer-ny.com 26/1(2007-03-01), 26-37 0721-7595 26:1<26 2007 26 344 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer