Disruption of a Novel NADH-Glutamate Synthase2 Gene Caused Marked Reduction in Spikelet Number of Rice

Inorganic ammonium ions are assimilated by a coupled reaction of glutamine synthetase and glutamate synthase (GOGAT). In rice, three genes encoding either ferredoxin (Fd)-GOGAT, NADH-GOGAT1, or NADH-GOGAT2, have been identified. OsNADH-GOGAT2, a newly identified gene, was expressed mainly in fully expanded leaf blades and leaf sheaths. Although the distinct expression profile to OsNADH-GOGAT1, which is mainly detected in root tips, developing leaf blades, and grains, was shown in our previous studies, physiological role of NADH-GOGAT2 is not yet known. Here, we isolated retrotransposon mediated-knockout mutants lacking OsNADH-GOGAT2. In rice grown under paddy field conditions, disruption of the OsNADH-GOGAT2 gene caused a remarkable decrease in spikelet number per panicle associated with a reductions in yield and whole plant biomass, when compared with wild-type (WT) plants. The total nitrogen contents in the senescing leaf blade of the mutants were approximately a half of the WT plants. Expression of this gene was mainly detected in phloem companion cells and phloem parenchyma cells associated with large vascular bundles in fully expanded leaf blades, when the promoter region fused with a β-glucuronidase gene was introduced into the WT rice. These results suggest that the NADH-GOGAT2 is important in the process of glutamine generation in senescing leaves for the remobilization of leaf nitrogen through phloem to the panicle during natural senescence. These results also indicate that other GOGATs, i.e., NADH-GOGAT1 and ferredoxin-GOGAT are not able to compensate the function of NADH-GOGAT2

ショウニ カンゴ ジッシュウ モクヒョウ ノ トウタツ ジョウキョウ ノ ケントウ ガクセイ ノ ジコ ヒョウカ ノ ブンセキ

看護基礎教育における臨床実習は、判断力、思考力、実践力を深め、さらに専門職者としての姿勢を身につけるために欠くことのできない教育内容・方法である。しかし、その学習環境は学内のそれとは大きく違い、学習者にとっては目標達成が困難な状況ともいえる。今回、実習目標の到達状況を学生の自己評価より分析した結果、(1)「カンファレンスを通しグループの受持ち小児の看護について理解を深める」と「自己の小児観、小児看護観を明らかにすることができる」の到達度が全体では高い。(2)目標到達度を左右する因子として、「実習病棟の違い」「実習時期」「保育実習経験」「実習病院における実習経験」が考えられる。以上のことがわかり、検討の結果、目標到達度を高めていくための指導内容・方法の改善課題が明確になった