Identification of Myosin on the Surface of Wheat Mitochondria

It was demonstrated that myosin was associated with the surface of mitochondria in wheat ( Triticum aestivum L. ). Assays of polyacrylamide gel electrophoresis and Western blotting have shown that a polypeptide with molecular weight of 210 kD could be recognized by a polyclonal antibody against hmnan muscle myosin. It was found that the ATPase activity of mitochondrial suspension could be stimulated by F-actin isolated from chicken muscle, which indicated that there was myosin on the surface of wheat mitochondria. This result was confirmed by electron microscopic observation: mitochondria treated with N-ethylmaleimide (NEM) could be wrapped by the F-actin.     

Relationship Between Isozymes of Starch Synthases and Starch Composition in Germination Pinyon Seedlings

The relation between starch synthases and starch composition in the germinating pinyon ( Pinus edulis Engelm) seedlings was studied. Using the method of 14C-glucose transferred from 14C-ADPG in the assay of starch synthases activity. Starch was extracted with 32% HC1O4, separated on glass fiber with DMSO, and assayed with the sulfuric acid-phenol method. After the emergence of radicle, starch content increased rapidly accompanied with the increase of starch grains in number and size, the increase of both soluble and granulebound starch synthase activity and the change of the pattern of Western-blot. Amylopectin was the major composition in pinyon starch, accounted for 84% of the total starch. The activity of soluble starch synthase was 1.3 times higher than that of the granule-bound starch synthase, corresponding to the ratio of amylopectin to amylose. This result supports the conventional theory that soluble starch synthase is the major enzyme responsive for the synthesis of amylopectin, and also supports that granule-bound starch synthase is functional in the synthesis of amylopectin.     

RAPD Study on Inter species Relationships in Roegneria (Poaceae: Triticeae)

To assess the relationships among 26 species in Roegneria C. Koch, 34 random decamer primers were screened for RAPD fragments. 28 primers produced polymorphic RAPD products. Data from 16 primers were used for RAPD assay. By NTSYS-pc program, Jaccard' s genetic similarity coefficients were generated and dendrogram was constructed using UPGMA. It is concluded as follows: (1) Distinct genetic differences and extensive genetic diversity were present among the species. (2) There were some genetic differences between StY and StYH genomes, and StY and StYH had a certain degree of differentiations respectively which were related to geographic regions, the farther the geographic distribution between species, the less the similarity to each other. (3) When different accessions in a species, such as species with similar morphological characters, homologous genomes and similar geographic distribution, were clustered together respectively, it suggusted that they had closer relationships. (4) The awnless species R. alashanica Keng and R. magnicaespes (D. F. Cui) L. B. Cai, in Roegneria, were separated from the other species analysed in this study, indicating that these two species had intensive genetic differences from the others. (5) R. caucasica C. Koch, a species from Western Asia, was quite different from the other species contained StY genomes in Roegneria from Eastern Asia and Central Asia. (6) The results were in consistance with that of the analysis of morphology and chromosome pairing in the taxonomic treatments for R. ciliaris (Trin) Nevski and R. japonensis (Honda) Keng, R. tenuispica J. L. Yang et Y. H. Zhou and R. pendulina Nevski, and R. tsukushiensis (Honda) Ohwi and R. kamoji Ohwi. The present study discussed the usefulness of RAPD markers in the systematic study of Roegneria.     

A novel recombinant adeno-associated virus vector packaging system with HSV-1 amplicon providing helper functions

A novel packaging system for producing recombinant adeno-associated virus (rAAV) vector was described. Instead of the conventional method for rAAV production by two-plasmid co-transfection followed by superinfection with adenovirus 5, an HSV-1 amplicon system expressing AAV-2 rep and cap genes from their native promoters was used to provide complete helper functions for rAAV replicating and packaging. This HSV-1 ampticon stock consisted of two kinds of infectious HSV-1 virions, a replicating-defective HSV-1 amplicon pseudovirus harboring multi-copies of AAV-2 rep and cap gene and a temperature-sensitive HSV-1 mutant strain ts-KOS. High-titer rAAV was generated with this new packaging system. This packaging system gives a simple and scaleable process for rAAV production.     

植物叶片衰老与氧化胁迫

叶片衰老是叶片生长发育进程中的最后阶段,与活性氧伤害有着密切的关系。介绍了植物叶片衰老过程中活性氧产生及清除系统的变化,讨论了对水分胁迫与氧化胁迫的交叉抗性,并对下一步的研究作出了展望。     

Biosystematic studies on Hystrix longearistata from Japan and Hystrix duthiei from China (Poaceae: Triticeae)

Morphological comparison, cytogenetic study and fertility analysis of Hystrix duthiei (2n = 28) from China, Hystrix longearistata (2n= 28) from Japan and their artificial hybrids were carried out. Morphologically H. duthiei was similar to H. longearistata. H. longearistata had longer lemma awn, wider leaf and 2～3 florets per spikelet, while H. duthiei had 1～2 florets per spikelet. These two taxa can be easily crossed. F_l hybrids showed very high degree of bivalent pairing (13～14 bivalents) at the metaphase- I of meiosis. No multivalents were found. The fertility of pollen and seed set of the parents were normal, while the F_l hybrids were of only partial fertility. H. longearistata was closely related to H. duthiei. They should be included in the same species. Because of the differences of their distributions and habitats, some morphological divergency and a little sterility barrier have had appeared between them. It is reasonable to treat Hystrix longearistata as a sub-species of Hystrix duthiei .