植物诱导抗虫基因研究进展

植物的诱导抗虫基因可分为3类，即防御基因、防御物质合成基因和信号途径基因，综述了这3类基因的种类及其功能。植物诱导抗虫基因除了受昆虫和损伤诱导外，还受植物激素茉莉酮酸酯、水杨酸、阿司匹林、脱落酸和乙烯，以及其它信号物质的调控，这些信号物质的调控途径组成了复杂的植物防御的信号传输网络。植物诱导抗虫基因的研究将为害虫防治提供新的途径。     

植物GDSL脂酶家族基因的研究进展

GDSL脂酶是指蛋白N'端具有保守GDSL序列的、广泛存在于原核和真核生物的一类水解酶。植物GDSL脂酶是一个大的基因家族,家族成员间存在较大的结构和功能多样性,在植物生长发育、逆境胁迫和油脂代谢等生理活动中发挥重要的生物学功能。本文对植物GDSL脂酶家族成员的结构、分类、进化、表达与功能上研究进展进行较为全面的综述,并简要介绍了本实验室有关GDSL基因在油料作物种子油脂积累过程中的作用方面的研究进展。     

植物盐诱导基因的研究进展

阐述了的几年有关植物盐诱导基因的研究进展,主要淑及与以下几个方面有关的分子克隆或基因：（１）渗透调节,包括对脯氨酸、甜菜碱、糖醇代谢的调节;（２）光合作用与代谢;（３）钙调蛋白;（４）通道蛋白;（５）胚相关蛋白等,并对本研究领域的发展趋势进行了讨论。     

植物病原细菌hrp基因研究进展

ｈｒｐ基因是一类决定病原细菌对寄主植物的致病性和在非寄主植物上激发过敏性反应的基因。由于它在寄主致病和非寄主抗病中的双重功能，使得ｈｒｐ基因的研究成为植物病原菌和植物互作研究领域中的一个重要内容。ｈｒｐ基因在植物病原细菌中的广泛存在及高度同源性说明不同植物细菌病害中存在着共同的机制。本文就植物病原细菌中ｈｒｐ基因的分布、特征、同源性、ｈｒｐ基因表达调控以及ｈｒｐ基因产物和功能等方面研究进展做一综述     

植物抗旱耐盐基因的研究进展

近几年许多与植物抗旱耐盐相关基因被克隆和分析,同时通过转基因技术将这些基因转到植物中异源表达,能显著提高转基因植物的抗旱耐盐能力。这些基因主要包括渗透调节基因、蛋白类基因（如信号传导中的蛋白激酶基因）及转录因子等。在逆境条件下,渗透调节基因通过合成脯氨酸、甜菜碱、糖类和多胺类等渗透调节物质维持植物中的渗透平衡;蛋白激酶基因产物是细胞信号传导中的组分,这些基因能促进植物对干旱失水反应和逆境信号的传递,启动抗逆基因的表达;转录因子通过与相关基因的特异性结合来调控其表达,进而产生相关调控蛋白等物质增强植物在逆境中的生存能力。本文主要综述了这三类抗逆基因的研究现状及其生物学机理,讨论并分析这些基因在应用中尚待解决的问题,为发掘更多的抗逆性的基因资源和进一步开展分子育种工作提供参考。     

植物耐盐性机理及基因控制技术研究进展

该文对近年来国内外植物耐盐性方面的研究成果作了简单的综述，包括植物的耐盐机制、盐胁迫对植物光合作用、细胞膜透性、激素、矿质元素吸收、有机物质的积累、保护酶类的活性的影响，以及植物的耐盐性在基因工程上的应用。     

植物耐盐性机理及基因控制技术研究进展

该文对近年来国内外植物耐盐性方面的研究成果作了简单的综述,包括植物的耐盐机制、盐胁迫对植物光合作用、细胞膜透性、激素、矿质元素吸收、有机物质的积累、保护酶类的活性的影响,以及植物的耐盐性在基因工程上的应用。     

利用基因工程技术改造植物脂质的研究进展

植物油脂是人们膳食的主要成份，占人体膳食总供热能的25％以上。营养科学研究表明，膳食脂肪的含量及组成与人体健康紧密相关。目前，人们很难采用常规的育种手段控制油脂的组成。然而，先进的基因工程技术为获得能满足食品功能和人体营养两方面需要的植物脂质提供了可能。本文介绍了挝年来利用基因工程技术改造植物脂质已取得的一些进展。     

基于BSA-seq的拟南芥辐射诱变突变体的基因定位

辐射诱变极易导致染色体结构变异,目前鲜有采用BSA-seq方法定位辐射诱变突变体基因的研究报道。为探索BSA-seq用于辐射诱变突变体的基因定位的可行性,本研究通过辐射诱变筛选得到一个拟南芥突变体,将其与亲本杂交,在F2代分离群体中根据表型筛选单株,构建两个极端表型的子代混池;将两个子代混池与亲本混池进行全基因组测序,使用MutMap、QTL-seq和GPS等多种BSA-seq定位策略对其进行定位分析。结果表明,多种BSA-seq定位策略均取得了一致的结果,在2号染色体上获得7 Mb的初步定位区间;使用IGV软件对该区间内的基因组进行可视化,发现该区间内存在25 189 bp的大片段缺失,缺失区段包含6个基因;通过SnpEff进行突变位点注释,经基因注释信息推测AT2G28610为候选基因;通过遗传学试验验证了该候选基因为突变基因。本研究结果为应用BSA-seq技术定位辐射诱变得到的突变位点提供了参考。     

Improving potassium acquisition and utilisation by crop plants

To avoid loss of yield, crops must maintain tissue potassium (K) concentrations above 5–40 mg K (g DM)^–1. The supply of K from the soil is often insufficient to meet this demand and, in many agricultural systems, K fertilisers are applied to crops. However, K fertilisers are expensive. There is interest, therefore, in reducing applications of K fertilisers either by improving agronomy or developing crop genotypes that use K fertilisers more efficiently. Agronomic K fertiliser use efficiency is determined by the ability of roots to acquire K from the soil, which is referred to as K uptake efficiency (KUpE), and the ability of a plant to utilise the K acquired to produce yield, which is referred to as K utilisation efficiency (KUtE). There is considerable genetic variation between and within crop species in both KUpE and KUtE, and chromosomal loci affecting these characteristics have been identified in Arabidopsis thaliana and several crop species. Plant traits that increase KUpE include (1) exudation of organic compounds that release more non‐exchangeable soil K, (2) high root K uptake capacity, (3) early root vigour, high root‐to‐shoot ratios, and high root length densities, (4) proliferation of roots throughout the soil volume, and (5) high transpiration rates. Plant traits that increase KUtE include (1) effective K redistribution within the plant, (2) tolerance of low tissue K concentrations, and, at low tissue K concentrations, (3) maintenance of optimal K concentrations in metabolically active cellular compartments, (4) replacement of K in its non‐specific roles, (5) redistribution of K from senescent to younger tissues, (6) maintenance of water relations, photosynthesis and canopy cover, and (7) a high harvest index. The development of crop genotypes with these traits will enable K fertiliser applications to be reduced.     

葡萄SBP基因家族生物信息学分析

SBP（squamosa promoter binding protein,SBP）基因家族是植物所特有的一类重要转录因子,广泛参与植物生长、发育以及多种生理生化反应的信号传导。葡萄是继拟南芥、水稻和杨树之后完成全基因组测序的第四种开花植物,因此葡萄逐渐成为分子生物学研究的重点对象,进行葡萄基因组信息挖掘与分析对于葡萄功能基因组学的发展具有重要意义。本文利用生物信息学方法对葡萄家族45条SBP蛋白序列的系统发生和SBP基因组定位进行分析,然后对其氨基酸组成成分、理化性质以及二级和三级结构进行预测和分析,同时还分析了葡萄与拟南芥的SBP基因家族之间的联系。结果显示这45条蛋白序列与拟南芥16个SBP基因蛋白序列一起分成了3个亚族,说明拟南芥与葡萄SBP基因间具有较高的保守性;进一步的基因组定位结果发现其分布在14条染色体上,较拟南芥在染色体上的分布更为分散。研究还发现不同亚家族间氨基酸数目、氨基酸序列间的疏水性存在一定的差异;而二级结构预测结果发现,41条氨基酸序列以随机卷曲为主要组成部分,这与拟南芥相似,且45条氨基酸序列三维结构十分相似。本文实验结果均为葡萄SBP基因家族的进一步功能分析提供了重要研究基础。     

Boron deprivation immediately causes cell death in growing roots of Arabidopsis thaliana (L.) Heynh.

Boron (B) is essential for the correct formation of cell wall structure because it is a component of borate-ester cross-links in pectin. Previously, we showed that removal of B from the culture medium immediately induced stress responses in suspension-cultured tobacco (Nicotiana tabacum L.) cells, but the mechanism by which cells exhibit such rapid responses remained unclear. In this study, we characterized the early responses of Arabidopsis thaliana (L.) Heynh. to B deprivation. Deprivation of B for 1 h caused cell death specifically in the root elongation zone. Reactive oxygen species accumulated in the same region, suggesting that the death was caused by oxidative damage. The B-deprivation treatment also induced the expressions of stress-responsive genes within 1 h. These results demonstrated that A. thaliana immediately senses and responds to the removal of B from the external medium. Similar responses were induced by calcium deprivation but not magnesium or potassium deprivation, suggesting that the failure of cross-linking in pectin molecules in growing cells triggers these rapid responses.     

A novel allele of the Arabidopsis phytochelatin synthase 1 gene conferring high sensitivity to arsenic and antimony

To identify genes involved in arsenite [As(III)] tolerance, we screened for As(III)-sensitive mutants using ethyl methanesulfonate (EMS)-mutagenized seeds of Arabidopsis thaliana. One mutant with high sensitivity to As(III) was isolated from the screening. It had a mutation in Glu⁵² of phytochelatin synthase 1 (AtPCS1), and introduction of the wild-type AtPCS1 gene rescued the phenotype, confirming that the mutant represented a new allele of atpcs1 (termed as cad1-7). The expression of AtPCS1 from cad1-7 and cad1-3, a second allele of atpcs1, complemented As-sensitive yeast, but not plants. Our study suggests that AtPCS1 activity is differentially regulated between plants and yeast.     

克隆包含以拟南芥为寄主的甘蓝黑腐病菌Xcc1067无毒基因的DNA片段

本研究探索了以拟南芥为寄主的甘蓝黑后病菌的致病条件，观察了其病症的发展．建立了菌株Ｘｃｃ１０６７的ｐＩＪ３２００为载体的基因文库，从基因文库中筛选出拟南芥Ｃｏｌｕｍｂｉａ为寄主的Ｘｃｃ１０６７菌株的无毒基因克隆，该克隆的进一步分析正在进行。     

水稻HTD1基因启动子在转基因拟南芥中的表达特征

通过分析β-葡萄糖醛酸苷酶(β-glucuronidase, GUS）基因产物,对水稻HIGH-TILLERING DWARF1(HTD1)基因启动子在转基因拟南芥中的表达特性进行初步研究。用已构建的含HTD1基因启动子和GUS报告基因的植物表达载体,通过农杆菌介导转化拟南芥,对转基因拟南芥进行GUS组织化学染色,观察该启动子的表达特性。结果表明,在HTD1基因启动子的驱动下,GUS报告基因主要在转基因拟南芥幼苗期的叶片、叶柄、下胚轴以及主根基部的维管组织中表达。     

UV-B诱导拟南芥查耳酮合成酶（CHS）基因表达及其信号传导途径

应用RT-PCR技术研究了6个拟南芥（Arabidopsis thaliana）株系的查耳酮合成酶（CHS）基因转录对UV-B照射以及过氧化氢（H2O2）、D/L-NG -一甲基精氨酸（D-NAME、L-NAME）和2-苯基-l-4,4,4,4-四甲基咪唑啉-1-烃氧基-3-氧化物（PTIO）等化合物处理的响应。结果表明，在6个株系中，Fah1-2突变株UV-B伤害最为敏感，而野生型WS2对UV-B伤害耐受力最强；在15 μmol/m2/s UV-B照射2 h，CHS基因转录产物明显增加，但24 h后消失。H2O2对CHS基因转录没有显著作用，D-NAME 和L-NAME能抑制CHS在UV-B照射下表达转录的增加，而PTIO对CHS基因表达的抑制作用很弱。据此认为，CHS基因对UV-B照射响应的表达和转录不受NO和H2O2的调节     

大麦过氧化物体膜上的抗坏血酸过氧化物酶拟南芥的耐盐机制

Ascorbate peroxidases （APX）, localized in the cytosol, peroxisome, mitochondria, and chloroplasts of plant cells, catalyze the reduction of H2O2 to water by using ascorbic acid as the specific electron donor. To determine the role of peroxisomal type ascorbate peroxidase （pAPX）, an antioxidant enzyme, in protection against salt-induced oxidative stress, transgenic Arabidopsis thaliana plant carrying a pAPX gene （HvAPX1） from barley （Hordeum vulgate L.） was analyzed. The transgenic line pAPX3 was found to be more tolerant to salt stress than the wild type. Irrespective of salt stress, there were no significant differences in Na^＋, K^＋, Ca^2＋, and Mg^2＋ contents and the ratio of K^＋ to Na^＋ between pAPX3 and the wild type. Clearly, the salt tolerance in pAPX3 was not due to the maintenance and reestablishment of cellular ion homeostasis. However, the degree of H2O2 and lipid peroxidation （measured as the levels of malondialdehyde） accumulation under salt stress was higher in the wild type than in pAPX3. The mechanism of salt tolerance in transgenic pAPX3 can thus be explained by reduction of oxidative stress injury. Under all conditions tested, activities of superoxide, glutathione reductase, and catalase were not significantly different between pAPX3 and the wild type. In contrast, the activity of APX was significantly higher in the transgenic plant than in wild type under salt stress. These results suggested that in higher plants, HvAPX1 played an important role in salt tolerance and was a candidate gene for developing salttolerant crop plants.