@article{oai:repository.naro.go.jp:00001831,
 author = {大平, 陽一 and OHDAIRA, Youichi},
 journal = {近畿中国四国農業研究センター研究報告, BULLETIN of THE NATIONAL AGRICULTURAL RESEARCH CENTER for WESTERN REGION},
 month = {Mar},
 note = {Effects of temperatures during the ripening period, cropping seasons and nitrogen application conditions on seed protein composition in rice grains ware analyzed quantitatively based on the SDS-PAGE technique using a normal-type rice cultivar and seed-protein mutant rice cultivars (SPMC) which have different genetic characteristics of protein composition in rice from normal-type rice cultivars. Also, the effects of the cultivation and environmental conditions on total protein contents (TP) in rice grains ware investigated and facters affecting protein compositions and contents were analyzed. In addition, characteristics of the protein distribution in rice grains were analyzed by SDS-PAGE analysis of rice grains which had different milling percentages and immunofluorescence microscopic analysis. A normal cultivar 'Nihonmasari' and a low-glutelin cultivar 'LGCsoft' were grown under a natural condition until the booting stage, and then in temperature-controlled greenhouses set at 24.0 ℃, 28.0 ℃, and 30.6℃ (mean temperature). The ratio of the PB-I (sum of 10～ 13 kDa prolamin) to total protein (PB-I/TP) was lower and the ratio of another protein fraction excepting 26 kDa globulin was higher in hightemperature conditions in both cultivars. Also, the effect of temperature on PB-I/TP was larger in 'LGCsoft' than in 'Nihonmasari'. The grain weight and PB-I/TP in the grains on the primary branches were higher than those on the secondary branches in both cultivars. The patterns of change in the protein compositions with the temperature during the ripening period were similar for the primary and the secondary branches. In field experiments of 'Nihonmasari', 'LGCsoft' and a low-glutelin 26-kDa-globulin-deficient cultivar 'LGC-Jun' over several years and cropping seasons, a negative correlation (r= -0.849^** ～ -0.773^*) between PB-I/TP and air temperature from 0 to 15 days after heading was observed in all cultivars. This tendency was similar to the result of artificially controlled temperature. It was considered that there were no relations between protein compositions in rice grain to the shoot nitrogen status or growth characteristics (for example, culm length) under different cropping seasons and years. There was a positive correlation between PB-I/TP and 1000-grain weight in 'Nihonmasari'. Based on the field experiments over several years and cropping seasons, a significant correlation between TP and temperature during the ripening period was not observed. However, as limiting in the same year, TP tended to be high by delayed transplanting with lowere temperature during the ripening period. Effects of the amount of nitrogen application and the timing of nitrogen topdressing on protein composition and TP in 'Nihonmasari', 'LGCsoft' and 'LGC-Jun' were examined. PB-I/TP became higher slightly under elevated TP conditions by high amount of nitrogen application. Similar to 'Nihonmasari' TP of SPMCs tended to be high under high nitrogen status of shoot at heading stage when larger application of nitrogen fertilizer and delayed nitrogen topdressing. It is considered that nitrogen topdressing at the neck node differentiation stage, which was about 10 days earlier than the panicle formation stage, enable to suppress TP compared to that at the panicle formation stage. In addition, yield was equal between the timing of nitrogen topdressing at the neck node differentiation stage and the panicle formation stage. Distribution of seed storage proteins in rice grain of 'Nihonmasari' and three SPMCs such as 'LGCsoft', a low-glutelin cultivar 'LGC-1' and a low-glutelin 26-kDa-globulin- deficient cultivar 'LGC-Katsu' was examined by SDS-PAGE analysis using rice with different milling percentage. All of the protein fractions tended to be higher in the outer layer of rice grain. However, 37-39 kDa glutelin α of 'LGC-Katsu', 57 kDa protein and 57 kDa excess protein of all cultivars were highest in the 100->90% layer, another protein fraction was highest in the 90->80% layer. It was revealed that localization patterns in rice grain were different depending on the type of protein and there were varietal differences of the protein localization. Characteristics of protein distribution in rice grain were examined directly by immunofluorescence microscopy using fluorescence-labeled antibodies of 13 kDa prolamin and 23 kDa glutelin. Abundant 13 kDa prolamin and 23 kDa glutelin was observed in the outer regions of rice grains. On the dorsal side of rice grain, 13 kDa prolamin and 23 kDa glutelin of SPMCs localized outer region than that of 'Nihonmasari'. Distribution patterns of 13 kDa prolamin of SPMCs differed from 'Nihonnmasari'. A larger quantity of 13 kDa prolamin localized on the ventral than the dorsal side of rice grain in SPMCs. This result was confirmed by SDS-PAGE analysis of grains grinding the ventral side or the dorsal side. It was suggested that the solar radiation during the ripening period and the nitrogen statas in shoot at the heading stage had large effect on TP rather than the temperature during the ripening period under different cropping years and seasons. To suppress TP and PB-I/TP in rice grain considering eating quality of cooked rice and sake making properties, it is important to not adjust the excessively delayed transplanting and also adjust the planting season to avoid extremely high temperatures during the ripening period. The desirable transplanting timing is considered to be until about mid-June from late-May with the reduction of applied nitrogen amount in warm region. This study revealed characteristics of distribution of seed storage proteins in rice grain of nomal-type rice cultivar and SPMCs. Therefore, these findings might be useful to remove specific seed storage proteins from rice grain by appropriate milling percentage for the various purposes.},
 pages = {1--49},
 title = {水稲種子貯蔵タンパク質の組成, 含有率に及ぼす栽培・環境条件の影響ならびに米粒内分布特性に関する研究},
 volume = {14},
 year = {2015},
 yomi = {オオダイラ, ヨウイチ}
}