The potential role of PR-8 gene of apple fruit in the mode of action of the yeast antagonist,Candida oleophila,in postharvest biocontrol of Botrytis cinerea

Several pathogenesis-related (PR) genes of apple have been cloned and their response to different pathogens has been studied. Different PR genes, however, may have a variable response depending on the specific organ or tissue as well as microbe. The objective of the current study was to characterize the expression of specific apple PR genes in fruit tissues in response to the antagonistic yeast, Candida oleophila (a common postharvest biocontrol agent), and the fungal pathogen, Botrytis cinerea (a major postharvest pathogen). Apple PR-5 and PR-8 gene expression was characterized in fruit in response to C. oleophila and B. cinerea. Results indicated that PR-8 expression was significantly elevated in response to both fungi. In contrast, neither C. oleophila nor B. cinerea treatment markedly affected PR-5 expression. The PR-8 gene was then synthesized and cloned into a Pichia pastoris expression system to study the antifungal activity of the PR-8 protein against B. cinerea both in vitro and in vivo. Collectively, the PR-8 gene of apple is associated with the response to B. cinerea infection, and may play a role in the mechanism by which C. oleophila effectively inhibits B. cinerea disease in apple fruit, namely by the induction of this specific host PR gene.     

Proteolytic activity in soil: A review

The aim of this work is to review current knowledge on inputs, sources and regulation of protease activities in soils from different ecosystems, while exploring limitations to proteolysis and N mineralisation. Extracellular proteases enter the soil via microbial production and other sources, including plant root exudates, animal excrements, decomposition processes and leaching from agro-industrial fertilisers. The synthesis and activities of proteases in soil are regulated by many factors, including climate, soil properties and the presence of organic compounds of plant and microbial origin. Two particularly important areas for future research are the regulation of proteolysis by low-molecular-weight organic compounds, including amino acids, sugars, flavonoids, plant hormones and siderophores, as well as the identification and characterisation of proteinaceous protease inhibitors of plant and microbial origin in the soil. Despite all the work that has been performed on soil proteases, our understanding of the roles of extracellular plant root proteases in N nutrition is weak. Furthermore, the regulation of soil proteolytic activities of different ecosystems, especially in terms of pollutant inputs and the impact of climate change, requires investigation. Other areas that pose important questions for the future include assessments of protease inhibitor inputs to the soil, regulation of these inhibitors via naturally occurring soil organic compounds and the interactions between soil organisms.     

韭菜迟眼蕈蚊紫外敏感视蛋白基因的克隆及光强度对其表达量影响

为明确韭菜迟眼蕈蚊Bradysia odoriphaga紫外敏感视蛋白基因Bo-uv的作用及其与趋光性的关系,利用常规PCR方法克隆获得Bo-uv基因的全长cDNA序列,分析了其敏感视蛋白的氨基酸序列与其它12种昆虫同源蛋白氨基酸序列之间的系统进化关系,运用qPCR技术检测了不同发育阶段、不同组织及不同光强度下Bo-uv基因的相对表达量。结果表明,Bo-uv基因cDNA全长2 757 bp,开放阅读框1 542 bp,编码514个氨基酸。韭菜迟眼蕈蚊紫外敏感视蛋白的氨基酸序列与其它12种昆虫同源蛋白的氨基酸序列一致性为21.93%～43.00%,与橘小实蝇Bactrocera dorsalis的氨基酸序列同源性最高。Bo-uv基因在韭菜迟眼蕈蚊蛹末期、成虫期表达,在成虫头部的相对表达量较高。在0～10 000 lx光强范围内雌、雄成虫体内该基因的相对表达量均呈先增高后降低趋势。与对照相比,1 000 lx光强度下其相对表达量显著升高,10 000 lx时相对表达量显著降低。表明光强度能够有效地调控Bo-uv基因的表达,该基因在韭菜迟眼蕈蚊感知外界光刺激过程中具有重要作用。     

云南省元阳县籼/粳型稻瘟病菌无毒基因Avr-Pia、Avr-Pita1和Avr-Pii多样性分析

为明确云南省元阳县籼/粳型稻瘟病菌中无毒基因的多样性及差异,采用接种鉴别品种方法和PCR技术对9株粳型菌株和21株籼型菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的多样性进行分析。结果显示,30株稻瘟病菌菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的平均出现频率分别为33.3%、76.7%和0,Avr-Pia、Avr-Pita1在籼型菌株和粳型菌株中的出现频率分别为4.8%和100.0%、66.7%和100.0%。Avr-Pia主要为存在/缺失的多样性,籼/粳型菌株对水稻品种Achiasahi(Pia)的致病率分别为100.0%和11.1%;Avr-Pita1可划分为3个类群,除菌株CH1195属于PO类群外,籼型菌株均属于J1类群,粳型菌株则属于J2/J3类群;籼/粳型菌株对水稻品种K1(Pita)的致病率分别为100.0%和0,且籼/粳型菌株Avr-Pita1蛋白序列在第83位和第192位氨基酸差异明显。Avr-Pii在30株稻瘟病菌菌株中均未检出,籼/粳型菌株对水稻品种Fujisaka No. 5(Pii)的致病率分别为100.0%和0。表明Avr-Pia和Avr-Pita1在粳型菌株中的出现频率高于籼型菌株且变异程度低,粳型菌株中可能存在其它无毒基因使其不能侵染Fujisaka No. 5。     

转Bt基因抗虫棉晋棉26号的生产特性及其配套技术

运用农杆菌介导法将Bt抗虫基因导入晋棉7号，获得抗虫棉品种晋棉26号。其纤维品质、产量性状与对照相当，属于高抗棉铃虫类型。棉铃虫防治不治2代，适当防治3代和4代。栽培措施是宜早浇水，早施肥，密植，不化控。     

芝麻苗期干旱生理生化指标响应特征及其基因表达分析

为建立芝麻抗旱性快速鉴定体系及筛选芝麻抗旱品种，采用盆栽反复干旱法，设置正常水分（CK）和干旱胁迫（DS）两种处理，对31份芝麻材料进行生理生化指标测定和综合评价，同时利用qRT-PCR检测SOD合成相关基因的表达量。结果表明：芝麻苗期O^₂、可溶性糖（SS）、脯氨酸（Pro）含量和超氧化物歧化酶（SOD）、过氧化物酶（POD）活性与CK相比均显著上升，各指标综合抗旱系数和抗旱指数的变异系数最高的分别是SOD（98.64%）和O^₂（154.01%）；抗旱指数与O^₂含量、SOD活性呈极显著正相关关系，这两个指标可作为芝麻苗期抗旱性鉴定的重要指标。聚类分析将31份芝麻材料划分为5类抗旱类型，分别为高抗型、中抗型、低抗型、低感型和高感型。利用综合评价方法，筛选出高抗材料2份（‘汾芝10号’和‘豫-11-1’），中抗旱材料4份，低抗旱材料9份，敏感材料10份，高感材料5份；筛选出O^₂含量和SOD活性可作为芝麻种质资源苗期抗旱特性快速鉴定的指标。     

南方水稻黑条矮缩病抗病遗传资源与分子机理研究进展

南方水稻黑条矮缩病（Souther rice black-streaked dwarf virus disease, SRBSDVD）是依靠白背飞虱（Sogatella furcifera）为传播介体，由南方水稻黑条矮缩病毒（Southern rice black-streaked dwarf virus，SRBSDV）侵染引起的一种水稻病毒病。该病害于 2001 年在我国华南地区首次被发现，随后发生面积不断扩大，危害逐年加重，已成为近年来危害中国南方稻区水稻生产的重要病害之一。白背飞虱迁飞性强、种群数量大、传毒持久等特点，导致化学农药防虫治病效果并不理想，至今还未有可持续和绿色控制 SRBSDVD 的手段。根据病原病毒的爆发性及其传播介体白背飞虱的生物学特性，预计该病害在未来较长的一段时期内将是我国最严重的水稻病害之一，很有可能再次暴发流行。因此，当前生产上急需培育出能够抵御 SRBSDVD 的抗性水稻品种。本文综述了 SRBSDVD 的发病规律、抗病种质资源的收集与评估、抗病基因或数量性状位点（QTL）的精确定位，以及这些抗性基因的分子作用机制，进一步探讨了利用现代分子生物学技术，包括分子标记辅助选择、基因沉默（RNAi）和基因编辑等技术加快 SRBSDVD 抗病品种的选育，可为今后有效控制 SRBSDVD 提供基础。     

Expression and Bioinformatic Analysis of ADIPOQ Gene in Hanper Sheep

The aim of this study was to investigate the expression and biological characteristics of adiponectin (ADIPOQ) gene in longissimus dorsi muscle of Hanper sheep at different months of age.The ADIPOQ gene mRNA expression was detected in longissimus dorsi muscle of Hanper sheep at 3 different growth periods (1,7 and 13 months old) by Real-time quantitative PCR.The bioinformatics method was used to analyze the nucleotide and amino acid sequences of ADIPOQ gene,protein characteristics and network interaction protein.The results showed that ADIPOQ gene was expressed in longissimus dorsi muscle of Hanper sheep,which showed an increasing trend with the growth of the months age without significant difference (P>0.05).There was higher homology of ADIPOQ gene with Capra hircus (98.60%,99.00%) and Bos taurus (98.60%,87.00%) in nucleotide and amino acid sequences.The results of physical and chemical properties analysis showed that the molecular formula of ADIPOQ protein was C₁₁₇₂H₁₇₇₆N₃₁₄O₃₄₉S₅,the molecular mass was 26.00 ku,and the theoretical isoelectric point (pI) was 5.88,which suggested that the protein was acidic.The average value of ADIPOQ hydrophilic protein (GRAVY) was －0.403,which indicated that the protein was hydrophilic and didn’t belong to transmembrane protein.In addition,the signal peptide sequence was Met¹-Ala¹⁷,and the cleavage site was between Ala¹⁷ and Arg¹⁸.ADIPOQ existed collagen structure domain and C1Q conserved structure domain at position 45－101 and 101－237,respectively.The secondary structure mainly composed of random coil (66.95%).The construction of protein interaction network indicated that ADIPOQ might interact with ADIPOR1,ADIPOR2,CDH13 and LEP.The results provided a theoretical basis for further exploring the molecular biological functions of ADIPOQ gene in the process of muscle development in Hanper sheep.