小麦根法细胞分化过程中木质素合成及其相关酶的活性变化

小麦根尖细胞分化过程中，苯丙氨酸解氨酸和对香豆酸辅酶Ａ联结酶的活性从分生区至成熟区逐渐增加入ＰＡＬ生在分生区细胞中为０，４ＣＬ活性近似为０，在成熟区细胞中ＰＡＬ和４Ｃ于均增加到最大，木质素的含量变化与ＰＡＬ和４ＣＬ活性存在着平行性，同样在分生区细胞中木质含量很低，到伸长区稍许增加，至成熟区增加最多，ＰＡＬ和４ＣＬ是木南素合成的开始步骤和关键酶，木质素主要在管状分子和细胞壁次生加厚时沉积，是细胞分化     

小麦根尖细胞分化过程中微丝骨架分布格局

以异硫氰四甲基若丹明－鬼笔环肽为探针,对小麦根尖三个不同发育区－分生区、伸长区和成熟区细胞中肌动蛋白纤丝（ＡＦｓ）的分布格局进行荧光显微观察和分析。结果表明：分生区细胞中细胞核为ＡＦｓ网络包围,细胞周缘有ＡＦｓ密集分布,胞质皮层中有ＡＦｓ有广泛均匀的分布;伸长区细胞中细胞核亦为网络包围,并明显可见ＡＦｓ成束由核周围向四处辐射直到细胞周质,且与分布于细胞边缘的ＡＦｓ汇集;成熟区细胞中伴随着核移向细胞     

甜瓜子叶不定芽分化过程中PAL活性和木质素含量变化研究

用组织培养的方法使甜瓜子叶脱分化形成愈伤组织，继而在分化培养基上形成不定芽。以此为系统，测定不定芽发生过程中ＰＡＬ活性变化和木质素含量变化。以肉桂酸、香草酸、苯甲酸、阿魏酸和咖啡酸为抑制剂，研究它们对不定芽发生的影响以及对系统中ＰＡＬ活性变化和木质素含量变化的影响。结果表明，五种抑制剂均抑制不定芽的发生。ＰＡＬ活性，木质素含量和愈伤组织分化成管胞、不定芽发生四者之间有密切的关系。     

丝瓜果实发育过程中4—CL连接酶的特性研究

以丝瓜果实为材料，分析了４－香豆酸辅酶Ａ连接酶（４－ＣＬ）的理化性质及其在木质素合成和导管分子（ＴＥ）分化中作用。发现４－ＣＬ存在两种同工酶，经柱层析后，酶Ｉ纯化１５．６８倍，含量为２２．６３％；酶Ⅱ纯化４４．２３倍，含量为３．９１％。酶Ｉ对得豆酸和咖啡酸有较大亲和性，对阿魏酸较小；而酶Ⅱ对香豆酸和咖啡酸有一定亲和性，对阿魏酸亲和性极小。酶Ｉ有较好的热稳定性，最适温度为４０℃，最适ｐＨ８．０。发现     

嗜黑液菌厌氧降解过程中木质素结构的变化

利用嗜黑液菌对木质素进行厌氧降解处理,研究在厌氧降解过程中,木质素的元素组成、分子量、结构基团的变化及其红外光谱和氢谱.结果表明,在厌氧降解过程中,分子量大于4 950的木质素将发生碎片化反应,尤其是木质素结构中的香豆满和松脂醇结构,以及β-O-4和β-β结构都因为发生断裂而消失,同时进一步发生脱甲氧基作用和脱羟基作用,生成了可溶性小分子化合物.     

绿液预处理过程中杨木木质素结构的变化

以绿液(Na₂S和Na₂CO₃)对杨木进行预处理,研究了预处理条件对木质素脱除的影响,并用碱性硝基苯氧化表征预处理后木质素化学结构特征的变化。结果表明:杨木原料木质素的碱性硝基苯氧化产物的总得率为2.61 mmol/g,其木质素非缩合部分紫丁香基结构的硝基苯氧化降解产物与愈疮木基摩尔比n(S+SA)/n(V+VA)为2.0; 随着预处理H-因子的升高和用碱量的增加,杨木浆料的木质素脱除率上升,n(S+SA)/n(V+VA)下降; 杨木浆料残余木质素的缩合程度随着木质素脱除率的增加而增大,且紫丁香基丙烷结构比愈疮木基丙烷结构在绿液预处理过程中更容易断裂。     

木质素硝酸降解及其产物的生理活性

采用硝酸降解木质素,并提取出高效植物生长调节物质．进行了化合物鉴定、化学合成研究以及初步的植物生长试验     

季铵型木质素的合成及其对AuCl4-的吸附性能

以稻草为原料,经酚化、交联和胺化后合成了季铵型木质素,并研究了其对AuCl-4的吸附性能.通过傅里叶红外光谱(FT-IR)、扫描电镜(SEM)和差热-热重分析(TG-DSC)对合成产物进行了表征,考察了AuCl-4初始浓度、盐酸浓度和吸附时间对AuCl-4吸附效果的影响.研究结果表明,合成的产物为热稳定性好且含有大量孔隙和表面粗糙的不规则块状季铵型木质素;在盐酸浓度为0.5 mol·L-1,AuCl-4初始浓度为6.0 mmol·L-1,吸附100 h时AuCl-4的最大吸附容量为3.27 mol·kg-1,在0.5 mol·L-1盐酸和1.0 mmol·L-1 AuCl-4的条件下吸附达到平衡时间为360 min.经扫描电镜和X射线衍射分析和傅里叶红外光谱分析表明吸附后的AuCl-4被季铵型木质素中的酚羟基还原而以单质形态析出.     

金针菇降解木质素的能力及相关酶活研究

通过对10个金针菇菌株研究发现,在液体培养下不同菌株降解木质素的能力有较大差异,其中金针菇J89-6具有一定的降解木质素的能力,降解率达46%.本文还测定了不同菌株的漆酶、木质素过氧化物酶和锰过氧化物酶三种木质素降解酶的酶活,结果显示漆酶的产量与木质素降解率呈正相关关系.     

发育过程中小麦叶片超弱发光及酶活变化

测定了发育过程中小麦叶片的超弱发光,以及叶片中的色素、蛋白质含量和几种抗氧化酶活性. 结果表明,叶片的超弱发光变化与CAT,POD活性呈显著正相关(P<0.01),与AP活性、蛋白含量变化呈显著负相关(P<0.01).     

Chromosome sorting and its applications in common wheat (Triticum aestivum) genome sequencing

The large genome size (～17000 Mb) and complicated DNA structures of common wheat (Triticum aestivum) hamper its genome sequencing.By means of flow cytometry,systematic investigations on individual chromosome sorting have been carried out to construct chromosome-specific bacterial artificial chromosome (BAC) libraries since the 1980s.Several wheat chromosome-specific BAC libraries,such as chromosome 3B,three D genome chromosomes (1D,4D and 6D),and the short arm of chromosome 1B,have been developed,and the ph...     

Protective effects of nitricoxide on salt stress-inducedoxidative damage to wheat(Triticum aestivum L.) leaves

The changes of chlorophyll and malondialdehyde (MDA) contents, plasma membrane permeability confirmed that 0.1 and 1 mmol/L sodium nitroprusside (SNP), a donor of nitric oxide (NO) in vivo, could markedly alleviate the oxidative damage to wheat (Triticum aestivum L.) leaves induced by 150 and 300 mmol/L NaCl treatments, respectively. Further results proved that NO significantly enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), both of which separately contributed to the delay of and H2O2 accumulation in wheat leaves under salt stress. Meanwhile, the accumulation of proline was apparently accelerated. Therefore, these results suggested that NO could strongly protect wheat leaves from oxidative damage caused by salt stress.     

不同基因型小麦成熟胚盾片组织培养效果研究

不同基因型及其外植体的愈伤组织诱导和植株分化研究是建立高效植株再生和遗传转化系统的基本条件。文章首次以去胚的成熟胚盾片为外植体材料,对10个小麦基因型进行了离体操作。结果显示:愈伤组织诱导率平均可达96.5%,10个基因型的愈伤组织都能分化出绿苗,分化频率最高可达10.5%,没有白苗化现象;根的分化与绿点、绿苗的分化之间具有显著的相关性;鄂恩1号的植株再生能力显著优于其它基因型,其植株再生系统已具备了遗传转化的基本要求。     

小麦体细胞胚发生中蛋白质组分和过氧化物酶同工酶的变化

用PAGE及薄层找扫描方法分析了小麦体细胞胚发生和发育的不同阶段蛋白质组分和过氧化物酶酶谱的变化。胚性愈伤组织,从球形胚、梨形胚,盾片胚到成熟胚不同发育时期蛋白质电泳图谱相似,与对照(非胚性愈伤组织)明显不同。前者有18KD,49KD,78KD的蛋白质组分,其含量随发育进程而上升。对照则无这些蛋白质组分或含量很低,但含有特异的14KD蛋白质。胚性愈伤组织和体细胞胚的不同发育时期过氧化物酶同工酶酶谱极其相似,都具有C_2、C_6、C_93条特异酶带,但活性有差异。对照不存在这3条酶带。再生苗的蛋白质电泳图谱和过氧化物酶同工酶酶谱介于胚性和非胚性组织之间。     

Molecular mapping of QTLs for root response to phosphorus deficiency at seedling stage in wheat (Triticum aestivum L.)

Phosphorus (P) deficiency in the soil is one of the major abiotic stresses that limit plant growth and crop productivity throughout the world. Development of cultivars with improved P-deficiency tolerance is an efficient strategy for sustainable agriculture. Plant roots play an important role in crop growth and development, especially in nutrient uptake and improvement of P-efficiency. Mapping quantitative trait loci (QTLs) for root traits and their response to low P stress at seedling stage will facilitate the development of P-efficient wheat cultivars. In this study, 30 QTLs (LOD>2.0) were mapped for the three root traits, such as root length, root number and root dry matter under different P supply conditions and their response to P-stress. These QTLs were distributed on 14 chromosomes, with each of the 5 QTLs explaining more than 10% phenotype variance. Analyses showed that root traits and their response to P-deficiency were controlled by different QTLs. In addition, alleles with positive effects were separated on both parents, and wheat cultivars with improved P-efficiency could be developed by accumulating these positive effect alleles together.     

Molecular mapping of QTLs for root response to phosphorus deficiency at seedling stage in wheat (Triticum aestivum L.)

Phosphorus (P) deficiency in the soil is one of the major abiotic stresses that limit plant growth and crop productivity throughout the world. Development of cultivars with improved P-deficiency tolerance is an efficient strategy for sustainable agriculture. Plant roots play an important role in crop growth and development, especially in nutrient uptake and improvement of P-efficiency. Mapping quantitative trait loci (QTLs) for root traits and their response to low P stress at seedling stage will facilitate the development of P-efficient wheat cultivars. In this study, 30 QTLs (LOD>2.0) were mapped for the three root traits, such as root length, root number and root dry matter under different P supply conditions and their response to P-stress. These QTLs were distributed on 14 chromosomes, with each of the 5 QTLs explaining more than 10% phenotype variance. Analyses showed that root traits and their response to P-deficiency were controlled by different QTLs. In addition, alleles with positive effects were separated on both parents, and wheat cultivars with improved P-efficiency could be developed by accumulating these positive effect alleles together.     

激素对小麦幼穗组织培养效果的影响研究

分析了激素对两个基因型小麦幼穗组织培养效果的影响,结果表明,愈伤组织诱导率在每个组合中均可达100％,诱导培养基中加入2,4-D对植株再生和绿点分化频率的效果要显著优于Picloram,在所采用的有效2,4D浓度范围内,随着浓度的升高,绿苗的再生频率呈现上升的趋势,2,4-D的量为4.5mg／L时,植株的再生频率平均可以达到45％左右。     

Cloning and sequencing of cDNA fragment of gene of wheat (Triticum aestivum. L) induced by dehydration

cDNA fragment of the gene (dehydration induced,di1) of wheat (Triticum aestivum. L) induced by 30% PEG-6000 (−1.13 MPa) treatment was isolated with mRNA differential display technique. Northern blot analysis showed that the expression ofdi1 gene improved at 10 h reached the highest at 48 h under 30% PEG-6000 treatment. cDNA fragment ofdi1 gene has been cloned and sequenced (211 bp). DNA sequence analysis shows that there is no homologue in GenBank todi1 cDNA.     

两个杂交组合中转基因小麦外源1Dx5基因的遗传

利用杂交组合川89-107×B72-8-11b和绵阳26×B72-8-11b的亲本、F1、F2代,研究转基因小麦B72-8-11b中外源品质基因1Dx5表达的遗传.结果表明:外源1Dx5基因在F1代中呈现显性,在F2代中呈现3(有):1(无)的分离,有功能拷贝整合在1个位点,遵从孟德尔遗传模式,这对杂交育种选择策略的制订具有指导意义.