Large-conductance calcium-activated potassium (BK(Ca)) channels are composed of the pore-forming alpha-subunit and the auxiliary beta-subunits. The beta4-subunit is dominantly expressed in the mammalian central nervous system. To understand the physiological roles of the beta4-subunit on the BK(Ca) channel alpha-subunit (Slo), we isolated a full-length complementary DNA of rat beta4-subunit (rbeta4), expressed heterolgously in Xenopus oocytes, and investigated the detailed functional effects using electrophysiological means. When expressed together with rat Slo (rSlo), rbeta4 profoundly altered the gating characteristics of the Slo channel. At a given concentration of intracellular Ca(2+), rSlo/rbeta4 channels were more sensitive to transmembrane voltage changes. The activation and deactivation rates of macroscopic currents were decreased in a Ca(2+)-dependent manner. The channel activation by Ca(2+) became more cooperative by the coexpression of rbeta4. Single-channel recordings showed that the increased Hill coefficient for Ca(2+) was due to the changes in the open probability of the rSlo/rbeta4 channel. Single BK(Ca) channels composed of rSlo and rbeta4 also exhibited slower kinetics for steady-state gating compared with rSlo channels. Dwell times of both open and closed events were significantly increased. Because BK(Ca) channels are known to modulate neuroexcitability and the expression of the beta4-subunit is highly concentrated in certain subregions of brain, the electrophysiological properties of individual neurons should be affected profoundly by the expression of this second subunit.

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A standard rose cultivar, 'To Dios'(Rosa hybrida) was selected for use as a cut flower from the progeny of a cross between 'Vanilla perfume' and 'Marcia' at the research and development division of the Goyang-si Agricultural Technology Center in 2013. 'Vanilla perfume', an orange-colored (RHS Orange Group 27C) standard rose cultivar with 48 petals, was used as the female plant. 'Marcia', a white-colored (RHS Green white Group 157B) standard rose cultivar with 96 petals was used as the male parent. A cross was made in 2009 and seedlings were produced. Selections were made between 2010 and 2013, and a plant with good cut flower traits was finally selected and named 'To Dios'. 'To Dios' is a standard rose with large flowers of 11.2 cm in diameter and 128 peach-colored (RHS Red Group 36B) petals per flower. Vase life of this cultivar is up to 15 days. It takes 47 days from pruning to blooming and cut flower productivity is approximately 160 stems/m 2 per year. 'To Dios' was registered as a new cultivar No. 4875 with the Korea Seed & Variety Service on March 19, 2014.