Suppression of glutamate synthase genes significantly affects carbon and nitrogen metabolism in rice (Oryza sativa L.)

Rice (Oryza sativa) glutamate synthase (GOGAT,EC 1.4.1.14) enzymes have been proposed to have great potential for improving nitrogen use efficiency,but their functions in vivo and their effects on carbon and nitrogen metabolism have not been systematically explored.In this research,we analyzed transcriptional profiles of rice GOGAT genes using a genome-wide microarray database,and investigated the effects of suppression of glutamate synthase genes on carbon and nitrogen metabolism using GOGAT co-suppressed rice plants.Transcriptional profiles showed that rice GOGAT genes were expressed differently in various tissues and organs,which suggested that they have different roles in vivo.Compared with the wild-type,tiller number,total shoot dry weight,and yield of GOGAT co-suppressed plants were significantly decreased.Physiological and biochemical studies showed that the contents of nitrate,several kinds of free amino acids,chlorophyll,sugars,sugar phosphates,and pyridine nucleotides were significantly decreased in leaves of GOGAT co-suppressed plants,but the contents of free ammonium,2-oxoglutarate,and isocitrate in leaves were increased.We conclude that GOGATs play essential roles in carbon and nitrogen metabolism,and that they are indispensable for efficient nitrogen assimilation in rice.

工厂化育苗原理与技术课程教学改革与实践

工厂化育苗原理与技术是设施农业科学与工程本科专业的专业课程,针对工厂化育苗与技术课程教学中存在的部分教学内容落后于产业实际、缺少教学素材库和教学案例、实验教学内容和考核方式落后、理论教学授课方式单一、教学团队薄弱等问题,华中农业大学工厂化育苗原理与技术课程组通过更新教学内容、修订出版教材,建设数字资源课程和慕课、提高教学资源共享性,探索基于MOOC/SPOC+翻转课堂教学,改进教学方式,邀请企业家进课堂,拓展创新创业教育,改革实验教学内容和考核方式,激发学生对实验课程兴趣,以及打造教学团队、培养青年教师等措施对课程教学进行全方位改革,取得了良好的教学效果。