OsHemA gene, encoding glutamyl-tRNA reductase(GluTR) is essential for chlorophyll biosynthesis in rice(Oryza sativa)

Chlorophyll(Chl) biosynthesis is essential for photosynthesis and plant growth.Glutamyl-tRNA reductase(GluTR) catalyzes glutamyl-tRNA into glutamate-1-semialdehyde(GSA) and initiates the chlorophyll biosynthesis.Even though the main role of GluTR has been established,the effects caused by natural variations in its corresponding gene remain largely unknown.Here,we characterized a spontaneous mutant in paddy field with Chl biosynthesis deficiency,designated as cbd1.With intact thylakoid lamellar structure,the cbd1 plant showed light green leaves and reduced Chl and carotenoids(Cars) content significantly compared to the wild type.By map-based gene cloning,the mutation was restricted within a 57-kb region on chromosome 10,in which an mPingA miniature inverted-repeat transposable element(MITE) inserted in the promoter region of OsHemA gene.Both leaf color and the pigment contents in cbd1 were recovered in a complementation test,confirming OsHemA was responsible for the mutant phenotype.OsHemA was uniquely predicted to encode GluTR and its expression level was dramatically repressed in cbd1.Transient transformation in protoplasts demonstrated that GluTR localized in chloroplasts and a signal peptide exists in its N-terminus.A majority of Chl biosynthesis genes,except for POR and CHLG,were down-regulated synchronously by the repression of OsHemA,suggesting that an attenuation occurred in the Chl biosynthesis pathway.Interestingly,we found major agronomic traits involved in rice yield were statistically unaffected,except for the number of full grains per panicle was increased in cbd1.Collectively,OsHemA plays an essential role in Chl biosynthesis in rice and its weak allele can adjust leaf color and Chls content without compromise to rice yield.

国外晶体测温技术研究与应用

系统介绍了国外一种创新型测温技术——晶体测温技术。简述了该技术的原理与特点及相较于传统测温方法的优势。总结了晶体测温技术在国外的研究应用概况,重点对其在国外航空发动机/燃气轮机涡轮叶片上的测试案例进行了分析,并给出了晶体测温技术在AI-25TL航空发动机、GTX100燃气轮机等上的实际测试结果。最后针对国内晶体测温技术的研究现状及所面临问题,提出了可供借鉴的意见,为国内晶体测温技术研发提供了支撑依据。

航空混合电推进系统的发展现状及应用前景

介绍了混合电推进系统的概念,以及以美国国家航空航天局、美国空军研究实验室、欧洲空中客车集团和俄罗斯中央航空发动机研究院为代表的国外组织在混合电推进系统领域的主要研究项目和发展现状,最后分析了混合电推进系统在城市空中交通、支线/干线客机、通航飞机等民用领域和忠诚僚机、高空长航时无人机、运输机和远程轰炸机、下一代战斗机等军用领域的应用前景。

扶正化瘀方对原代大鼠肝细胞中CYP450的影响

目的：采用原代大鼠肝细胞（PRH）研究扶正化瘀方（FZHY）对大鼠细胞色素P450酶（CYP450）的影响。方法：采用两步灌流法分离大鼠原代肝细胞,形成肝板结构后加入FZHY共培养24 h,换成含有4种CYP450同工酶（CYP1A2,CYP2C9,CYP2D6,CYP3A4）对应的特异性探针药物（非那西丁、甲苯磺丁脲、氢溴酸右美沙芬、睾酮）的培养基,培养2 h后吸取上清液,利用UPLC-MS/MS对探针药物的代谢产物进行检测,考察FZHY对探针药物代谢产物生成量的影响,评价FZHY对PRH中CYP450代谢活力的影响。结果：PRH中CYP1A2,CYP2C9,CYP2D6与CYP3A4具有良好的代谢活力。4种探针药物在0-500μmol·L（-1）内对PRH没有毒性,在0.5-500μg·L（-1）时,FZHY对PRH没有毒性。FZHY在5μg·L（-1）时对PRH具有轻微的保护作用,并能使甲苯磺丁脲的代谢活化值——米氏常数（Km）降低20.8%;氢溴酸右美沙芬的Km降低39.2%;非那西丁的Km降低17.4%;并使睾酮的Km显著降低。结论：FZHY能抑制原代大鼠肝细胞中CYP1A2,CYP2C9,CYP2D6和CYP3A4的代谢活性。