In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series...In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series of spikelet meristem (SM) as the branch. The SM then produces a series of floret meristem (FM) as the branch. To identify the mechanisms that regulate formation of the reproductive meristems in wheat, we have investigated a leaf initiation mutant, fushi-darake (fdk) which was developed by ion beam mutagenesis. The morphological traits were compared in wild type (WT) and fdk mutant plants grown in the experimental field. WT plants initiated leaves from SAM at regular intervals in spiral phyllotaxy, while fdk plants had 1/2 alternate phyllotaxy with rapid leaf emergence. The fdk plants have increased numbers of nodes and leaves compared with WT plants. The time interval between successive leaf initiation events (plastochron) was measured in plants grown in a growth chamber. The fdk plants clearly show the rapid leaf emergence, indicating a shortened plastochron. Each tiller in fdk plants branches at the upper part of the culm. The fine structure of organ formation in meristems of fdk plants was examined by scanning electron microscopy (SEM). The SEM analysis indicated that fdk plants show transformation of spikelet meristems into vegetative shoot meristems. In conclusion, the fdk mutant has a heterochronic nature, i.e., both reproductive and vegetative programs were simultaneously in operation during the reproductive phase, resulting in a shortened plastochron and transformation of reproductive spikelets into vegetative shoots.展开更多
OBJECTS: Hydrogen has been shown to possess antibacterial effects at high concentrations. In addition, chlorine has a strong bactericidal effect even at low concentrations. Electrolysis is a way to simultaneously gene...OBJECTS: Hydrogen has been shown to possess antibacterial effects at high concentrations. In addition, chlorine has a strong bactericidal effect even at low concentrations. Electrolysis is a way to simultaneously generate these two components. However, the concentration of hydrogen/free chlorine mixed water generated through electrolysis decreases quickly. It is predicted that the concentration of hydrogen/free chlorine mixed water will vary depending on the quality of water used. After investigating the optimum generation conditions, the effects of the most stable concentration of hydrogen/free chlorine mixed water on carious tooth fungus were evaluated in vitro. Thus, in this experiment, our goal was to evaluate the effects of hydrogen/free chlorine mixed water on oral bacteria. MATERIALS AND METHODS: Using a device that generates hydrogen/free chlorine through electrolysis, the differences in the concentrations of hydrogen and free chlorine based on electrolysis time were evaluated using tap water. Additionally, various concentration changes due to electrolysis time on the hydrogen/free chlorine mixed water were evaluated. Distilled tap water as a control group, hydrogen/free chlorine mixed water, and commercially available mouthwash were added for 1 minute to cultured Streptococcus mutans and then rinsed out with the culture medium. Bacterial growth (600 nm) and biofilm formation (590 nm) were measured at 3 and 6 hours after the addition of the medium. RESULTS: The concentration of hydrogen/chlorine mixed water produced by electrolysis varied depending on electrolysis time and the water used. The inhibitory effect of bacterial growth was enhanced depending on the chlorine concentration. Regarding the inhibitory effect on biofilm formation, only the mixed water of hydrogen/free chlorine concentration (500 ppb - 1.0 mg/L) had a suppressing effect after 6 hours. CONCLUSION: It was suggested that hydrogen/chlorine mixed water can be easily produced by electrolysis and has the effect of suppressing the growth of dental caries;therefore, it could be used as a cleaning agent in oral care products.展开更多
文摘In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series of spikelet meristem (SM) as the branch. The SM then produces a series of floret meristem (FM) as the branch. To identify the mechanisms that regulate formation of the reproductive meristems in wheat, we have investigated a leaf initiation mutant, fushi-darake (fdk) which was developed by ion beam mutagenesis. The morphological traits were compared in wild type (WT) and fdk mutant plants grown in the experimental field. WT plants initiated leaves from SAM at regular intervals in spiral phyllotaxy, while fdk plants had 1/2 alternate phyllotaxy with rapid leaf emergence. The fdk plants have increased numbers of nodes and leaves compared with WT plants. The time interval between successive leaf initiation events (plastochron) was measured in plants grown in a growth chamber. The fdk plants clearly show the rapid leaf emergence, indicating a shortened plastochron. Each tiller in fdk plants branches at the upper part of the culm. The fine structure of organ formation in meristems of fdk plants was examined by scanning electron microscopy (SEM). The SEM analysis indicated that fdk plants show transformation of spikelet meristems into vegetative shoot meristems. In conclusion, the fdk mutant has a heterochronic nature, i.e., both reproductive and vegetative programs were simultaneously in operation during the reproductive phase, resulting in a shortened plastochron and transformation of reproductive spikelets into vegetative shoots.
文摘OBJECTS: Hydrogen has been shown to possess antibacterial effects at high concentrations. In addition, chlorine has a strong bactericidal effect even at low concentrations. Electrolysis is a way to simultaneously generate these two components. However, the concentration of hydrogen/free chlorine mixed water generated through electrolysis decreases quickly. It is predicted that the concentration of hydrogen/free chlorine mixed water will vary depending on the quality of water used. After investigating the optimum generation conditions, the effects of the most stable concentration of hydrogen/free chlorine mixed water on carious tooth fungus were evaluated in vitro. Thus, in this experiment, our goal was to evaluate the effects of hydrogen/free chlorine mixed water on oral bacteria. MATERIALS AND METHODS: Using a device that generates hydrogen/free chlorine through electrolysis, the differences in the concentrations of hydrogen and free chlorine based on electrolysis time were evaluated using tap water. Additionally, various concentration changes due to electrolysis time on the hydrogen/free chlorine mixed water were evaluated. Distilled tap water as a control group, hydrogen/free chlorine mixed water, and commercially available mouthwash were added for 1 minute to cultured Streptococcus mutans and then rinsed out with the culture medium. Bacterial growth (600 nm) and biofilm formation (590 nm) were measured at 3 and 6 hours after the addition of the medium. RESULTS: The concentration of hydrogen/chlorine mixed water produced by electrolysis varied depending on electrolysis time and the water used. The inhibitory effect of bacterial growth was enhanced depending on the chlorine concentration. Regarding the inhibitory effect on biofilm formation, only the mixed water of hydrogen/free chlorine concentration (500 ppb - 1.0 mg/L) had a suppressing effect after 6 hours. CONCLUSION: It was suggested that hydrogen/chlorine mixed water can be easily produced by electrolysis and has the effect of suppressing the growth of dental caries;therefore, it could be used as a cleaning agent in oral care products.
