Biological Characterization of Heat-stable Antifreeze Proteins from Leaves of Ammopiptanthus mongolicus

Antifreeze protein(afp) was purified from the heat stable proteins in the leaves of Ammopiptanthus mongolicus (Maxim.) Cheng f. by two-dimensional electrophoresis-electrophoretic elution. Its molecular weight and pi are about 40 kD and 9.0 respectively, and its thermal hysteresis activity (THA) is 0.9 ℃ at 20 g/L. afp is different from other antifreeze proteins. The N-terminal 20 amino acids of afp is SDDLSFTFNKFVPCQTDILF. alp is abundant in leaves and may play an important role in the antifreeze process in A. mongolicus during the period of ovenwintering.     

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.     

籼稻和粳稻中蜡质基因座位上微卫星标记的多态性及其与直链淀粉含量的关系

稻米直链淀粉是在由蜡质基因Wx编码的颗粒结合淀粉合成酶（GBSS）的催化下合成的。最近,在Wx基因的区段内发现了一段多态性微卫星序列（CT）n。对74个非糯籼稻和粳稻材料的（CT）n多态性进行了分析,并探讨了其与直链淀粉含量之间的关系。在74个品种（系）中共发现7种（CT）n片段（Wx等位基因）,即（CT）8,（CF）10,（CT）11,（CT）16,（CT）17,（CT）18,（Ch）19。在籼粳亚种间,不同（CT）n的分布存在差异较大：在籼稻中,以（CT）11和（CT）18为主,占92．6％,另有（CT）10和（CT）8各2份,（CT）17型1份;在粳稻中,以（CT）16、（CT）17为主,共占20份材料中的90．0％。在上述74个品种（系）中,以（CT）n表示的Wx基因型对稻米直链淀粉含量的决定系数R2达0．912,也即Wx基因型差异可解释这些材料直链淀粉含量变异的91．2％。还发现6份籼稻材料Wx座位上为杂合的（CT）18／（CT）11,其中2份为推广早籼优质品种浙9248和舟优903,并对其在遗传和育种研究中的意义作了探讨。     

植物耐干旱胁迫的生物学机理及其基因工程研究进展

本文介绍了干旱胁迫对植物的伤害,植物耐早性的生物学机理以及通过基因工程改良作物耐旱性的研究进展。     

Expression of IAA-Lysine Synthetase Gene Caused Variations of Flower Develop ment in Transgenic Tobacco

The indoleacetic acid-lysine synthetase (iaaL) gene of Pseudornonas syringae subsp. savastanoi was fused to a rice Rchl0 promoter and introduced into tobacco plants. The expression pattern of this chimeric Rchl0-iaaL gene in the transgenic plants was studied, and the endogenous levels of indoleacetic acid (IAA) were assayed with the high-performance liquid chromatography (HPLC) method. The results showed that the Rchl0 promoter could direct the high level expression of the iaaL gene in young inflorescences, fully bloomed flowers, and immature fruits, resulted in a decrease of the IAA levels by 32%–82%. The transgenic plants displayed decreased apical dominance, enlongated stamens, abnormal inflorescences and fruits. The transgenie plant pYL614-T14, in which the endogenous IAA levels in inflorescences were reduced by 82 %, displayed extremely abnormal inflorescence with only two flowers and a much higher potential of vegetative growth than that of the controls after flowering. These Rchl 0-iaaL gene transgenic tobacco plants would pro- vide valuable materials for further studies of physiological functions of IAA in reproductive development.     

植物蛋白电泳分析的方法学研究及技术改进

本文在采用多种方法进行植物蛋白质电泳分析的基础之上,对植物蛋白进行了电泳分析的方法学研究,论述了多种电泳技术的理论概要、关键步骤、实验要领及我们的一些改进。