甜菜叶绿体DNA分离纯化方法

通过研究建立了适宜甜菜ctDNA的分离纯化方法，应用该方法可以获得高纯度、高得率的甜菜ctDNA。且产物可直接用于限制性内切酶酶切分析。     

景天属植物叶绿体DNA与核DNA分步提取方法研究

[目的]研究景天属植物叶绿体DNA与核DNA分步提取方法.[方法]以景天属植物佛甲草、八宝景天、华北景天、费菜和垂盆草为研究材料,进行叶绿体DNA和核DNA的分步提取,通过琼脂糖凝胶电泳和PCR扩增进行检测.[结果]改进后的方法提取的核DNA和叶绿体DNA的质量好,纯度高.以叶绿体DNA和核DNA为模板进行PCR扩增均得到理想的条带,扩增率为100％,重复性好.[结论]该研究为叶绿素DNA和核DNA的提取提供了新的思路.     

Presence of chloroplasts in mestome sheath cells of the C3 Pooid grass Elymus tsukushiensis

ABSTRACT

The successful introduction of the C₄ pathway into C₃ crops would increase photosynthetic rates and crop productivity. However, our poor understanding of how Kranz leaf anatomy develops poses a great obstacle. In particular, the origin, development, and genetics of bundle sheath (BS) cells in C₄ plants are key points to elucidate. Here we report that Elymus tsukushiensis, a common C₃ grass of the subfamily Pooideae, contains chloroplasts in the mestome sheath (MS) cells of the leaf, unlike most MS cells of C₃ grasses. The chloroplasts are smaller than those of mesophyll cells. Immunogold localization showed that the chloroplasts and mitochondria of MS cells, respectively, accumulate ribulose 1,5-bisphosphate carboxylase/oxygenase and a photorespiratory enzyme, glycine decarboxylase, as in mesophyll cells. Thus, we suggest that the MS cells have weak photosynthetic and photorespiratory functions. This finding provides an insight into the development and evolution of C₄-type BS cells in leaves of C₃ grasses.     

小麦黄化突变体类囊体蛋白组分及叶绿素的合成特性

为进一步探讨冬小麦品系"西农1718"自然黄化突变体的突变机制,利用SDS-尿素-聚丙烯酰胺凝胶电泳对该黄化突变体及其突变亲本叶绿体类囊体蛋白组分进行比较研究.结果表明,与突变亲本相比,黄绿株(黄化程度较轻的中间型)的60～64 kD和42～54 kD多肽无明显变化,而绿黄株(黄化程度较深的中间型)和金黄株显著减少,且金黄株减少幅度大于绿黄株;黄绿株、绿黄株的33～35 kD多肽表达量明显低于突变亲本,且绿黄株减少幅度大于黄绿株;23和27 kD多肽在突变体中的变化最为显著,金黄株缺失,黄绿株和绿黄株也大幅降低;16～19 kD多肽,黄绿株与突变亲本无明显差异,金黄株和绿黄株大幅度降低.对叶绿素生物合成主要前体物质累积量分析表明,金黄株、绿黄株和黄绿株的δ-氨基乙酰丙酸(ALA)、胆色素原(PBG)、尿卟啉Ⅲ(UrogenⅢ)、粪卟啉原Ⅲ(Coprogen Ⅲ)和原卟啉Ⅸ(ProtoⅨ)的含量均高于突变亲本,且随突变体黄化程度加深而递增,尤其ProtoⅨ累积更为显著,分离绿株与突变亲本无差别;而金黄株、绿黄株和黄绿株自ProtoⅨ以后的中间产物钱原卟啉(Mg-Proto Ⅸ)、原脱植基叶绿素酸酯(Pchlide)的含量均显著低于突变亲本,且随突变体黄化程度加深而递减,分离绿株与突变亲本无明显差异.因此初步认为,该黄化突变体叶绿素合成受阻,且受阻位点发生在ProtoⅨ到Mg-Proto部位.     

Molecular analysis of lipoxygenase (LOX) genes in common wheat and phylogenetic investigation of LOX proteins from model and crop plants

Lipoxygenase (LOX) proteins constitute an important class of lipid-hydrolyzing enzymes in cellular organisms. Here, we report a molecular analysis of LOX genes in common wheat (Triticum aestivum L.) and a more comprehensive phylogenetic investigation of the LOX proteins from higher plants. The full-length nucleotide sequences of two LOX genes (TaLOX1 and TaLOX2) from common wheat were isolated. TaLOX1 and TaLOX2 were assigned to the short arm of chromosome 4D and the long arm of chromosome 5D, respectively. TaLOX1 and TaLOX2 were both expressed in the developing grains of two common wheat varieties, indicating that they may contribute to the total LOX activity in common wheat seeds. A more extensive phylogenetic analysis conducted with 143 unique LOXs from model and crop plants revealed that plant LOXs could be classified into two subfamilies, which correlated with the absence (subfamily I) or presence (subfamily II) of a predicted chloroplast targeting peptide in the deduced LOX proteins. Our work provides new information on the LOX genes in common wheat and the phylogenetic relationships of higher plant LOXs, which may aid further functional and evolutionary studies of plant LOXs.     

部分箬竹属植物的叶绿体DNA分析

[目的]研究箬竹属植物和赤族属植物的亲缘关系。[方法]以箬竹属13个竹种及其近缘的赤竹属3个竹种为材料,采用PCR方法扩增叶绿体trnL-trnF间隔区基因片段,并对其进行序列分析,构建系统树。[结果]利用已发表的trnL-trnF序列通用引物扩增出长度为1008～1103bp的trnL-trnF片段,比较长度为940bp。cpDNA序列聚类将箬竹属与赤竹属竹种混合聚在一起,同源性为99%以上,可分为5组。其中,髯毛箬竹、广东箬竹、小叶箬竹、华箬竹、毛鞘箬竹、矮箬竹、胜利箬竹、箬竹、箬叶竹、粽巴箬竹、翠竹和菲白竹12个竹种聚为一组;泡箬竹、天目箬竹、阔叶箬竹和美丽箬竹4个竹种各自成一组。[结论]竹种间的同源性极高,表现为较慢的进化速率,提供的信息位点很少,不能很好地解决箬竹属种间的系统学问题。     

Fusaproliferin effects on the photosystem in the cells of maize seedling leaves

The possible role of the fusariotoxin, fusaproliferin in plant pathology was investigated with respect to cell membrane potential. Electron microscopy was used to study both the early effect of fusaproliferin on the host’s plasma membrane and ultrastructure responses in the cells of maize leaves. The seedlings of resistant (Lucia) and susceptible (Pavla) to the fusaproliferin maize cultivars were grown in the presence of fusaproliferin at different concentrations, namely 5 and 35 μg ml⁻¹, respectively, and electrophysiological measurements were compared with those obtained using two different toxic compounds, namely fusicoccin and 3-3(3,4 dichlorophenyl)-1,1-dimethylurea (DCMU). It was observed that only the higher concentration of fusaproliferin induced the onset of visible symptoms on the leaves. Comparing the effect of fusaproliferin to that of fusicoccin and DCMU at the higher toxin concentration, it was observed that functional differences in membrane potential induced severe damage to the mesophyll and outer chloroplast membrane; the extent of changes in electrophysiology and ultrastructure disturbances depended on the toxin concentration and was greater in the susceptible cv. Pavla. Results indicated that fusaproliferin could be involved in Fusarium pathogenesis either as a virulence factor or by enhancing the activity of other toxins that might be concomitantly present in infected plants.     

3个木薯品种的叶绿体基因组16S rRNA-23S rRNA基因间隔序列的特征分析

以华南6、8、10号木薯为材料,通过PCR克隆3个木薯品种的叶绿体16S-23S基因间隔序列,与其他17种植物的该序列进行亲缘关系分析。从进化树可以看出,该序列进化分析符合Webster分类系统,同科植物可以很好的聚为1类。此外,3个木薯品种的16S-23S基因间隔序列相似性高达99.94%;大戟科间的序列相似性为97.52%;其他植物科内的序列相似性不低于96%。该研究还分析了3个木薯品种16S-23S基因间隔序列的基因分布,该序列的基因分布情况一致,包含16S rRNA 5′端,trnI基因,ycf68基因,trnA基因,23SrRNA3′端,ISR-B,发现该序列的保守性较强,个别碱基差异并不影响基因分布,该研究可为后期木薯叶绿体遗传转化体系建立提供理论依据。     

Relationships among <Emphasis Type="Italic">Avena</Emphasis> species as revealed by consensus chloroplast simple sequence repeat (ccSSR) markers

Consensus chloroplast simple sequence repeat (ccSSR) makers were used to assess the genetic variation and genetic relationships of 80 accessions from 25 taxa of the genus Avena. Fifteen out of 16 ccSSR markers (93.75%) were polymorphic. A total of 51 alleles were detected at the 16 ccSSR loci. The number of alleles per locus ranged from 1 to 6, with an average of 3.2 alleles. Among these ccSSR loci, the highest polymorphism information content (PIC) value was 0.754, while the lowest PIC value was 0. The mean genetic similarity index among the 80 Avena accessions was 0.545, ranging from 0.188 to 1.000. To assess the usefulness of ccSSRs in separating and distinguishing between haplome (genome) groups, we used ordination by canonical discriminant analysis and classificatory discriminant analysis. Although discriminant analysis separated the haplome groups unequivocally, it was up to 69% predictive of correctly classifying an individual plant whose haplome(s) is unknown in the case where it belonged to the A haplome group, 75% where it belonged in the AC group, and almost 80% where it belonged in the ACD group. The analysis of genetic similarity showed that diploid species with the A haplome were more diverse than other species, and that the species with the As haplome were more divergent than other diploid species with the A haplome. Among the species with the C haplome, A. clauda was more diverse than A. eriantha and A. ventricosa. In the cluster analysis, we found that the Avena accessions with the same genomes and/or belonging to the same species had the tendency to cluster together. As for the maternal donors of polyploid species based on this maternally inherited marker, A. strigosa served as the maternal donor of some Avena polyploidy species such as A. sativa, A. sterilis and A. occidentalis from Morocco. A. fatua is genetically distinct from other hexaploid Avena species, and A. damascena might be the A genome donor of A. fatua. Avena lusitanica served as the maternal parents during the polyploid formation of the AACC tetraploids and some AACCDD hexaploids. These results suggested that different diploid species were the putative A haplome donors of the tetraploid and hexaploid species. The C genome species A. eriantha and A. ventricosa are largely differentiated from the Avena species containing the A, or B, or D haplomes, whereas A. clauda from different accessions were found to be scattered within different groups. Wei-Tao Li and Yuan-Ying Peng have contributed equally to this paper.     

Improved insect‐proofing: expressing double‐stranded RNA in chloroplasts

RNA interference (RNAi) was discovered almost 20 years ago and has been exploited worldwide to silence genes in plants and animals. A decade later, it was found that transforming plants with an RNAi construct targeting an insect gene could protect the plant against feeding by that insect. Production of double‐stranded RNA (dsRNA) in a plant to affect the viability of a herbivorous animal is termed trans‐kingdom RNAi (TK‐RNAi). Since this pioneering work, there have been many further examples of successful TK‐RNAi, but also reports of failed attempts and unrepeatable experiments. Recently, three laboratories have shown that producing dsRNA in a plant's chloroplast, rather than in its cellular cytoplasm, is a very effective way of delivering TK‐RNAi. Our review examines this potentially game‐changing approach and compares it with other transgenic insect‐proofing schemes. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.