Atmospheric characterization has become a crucial area of study for exoplanets. The exoplanets known as ultra-hot Jupiters (UHJs) offer a natural laboratory for studying extreme atmospheric physics that cannot be observed in the solar system. One way to analyze their atmospheres is by transmission spectroscopy. However, it can be challenging to obtain such information because a planet’s signal is too weak compared to that of its host star, resulting in the planetary contribution to the observed spectrum being negligible. Therefore, the minimum observational requirements must be assessed first to distinguish the planetary signal from the stellar one to study these planets. In this context, we obtained the transmission spectra of UHJs TOI-1431 b and WASP-189 b by observing each exoplanet for one night with BOAO Echelle Spectrograph (BOES) on the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO). We searched for various chemical species by cross-correlating the exoplanetary spectra with model synthetic spectra. Our search for atmospheric signal returned a detection confidence level less than 3 σ for both targets. Therefore, we applied model injection to recover the atmospheric signals of the planets and assessed the minimum signal-to-noise ratio (S/N) to achieve 5 σ detection. During our search, we successfully recovered the planet signals with detection significances of 5.11 σ after a 750% injection of the model signal for TOI-1431 b and 5.02 σ for a 90% injection forWASP-189 b. These signal injection exercises suggest that a higher S/N of the transmission spectra is required to detect the planetary absorption features, and this can be done by stacking data from the observations of more than three cycles of the transit of a planet with a small-scale height such as WASP-189 b at BOAO facilities.

Rice (Oryza sativa L.) plants were cultivated to examine changes in antioxidative defence mechanism induced by elevated ozone levels. Catalase activities in tolerant Jinpumbyeo and susceptible Chucheongbyeo under ozone fumigation were reduced at 5 hrs and 3 hrs after ozone fumigation, respectively. With the increased ozone supply, peroxidase activity in Jinpumbyeo was steadily enhanced whereas in Chucheongbyeo it was not changed. Four SOD-isozymes were detected by NBT staining of native-PAGE. Two isozymes of them were obviously induced by ozone supply, particularly in Jinpumbyeo. The continuous ozone fumigation increased remarkably putrescine levels in leaves whereas it did not affect the levels of spermidine and spermine. In this study, it was implied that ozone in cell inhibits strongly diamine oxidase and thus promotes ethylene biosynthesis which will cause the senescence in rice plants.