利用DNA ISSR分子标记技术对芍药属植物栽培品种的分类鉴定方法

以利用DNA ISSR分子标记逐级区分品种为主要研究目标,通过ISSR引物的设计与实验筛选,取得了进展。该方法类似于经典的植物形态检索表式的分类策略,不同之处在于利用基因组DNA分子性状作为品种分类的依据,即"ISSR引物结合位点"与"DNA ISSR片段长度差异"的组合信息。该方法不仅可以有效鉴定品种,而且可以很容易地生成富含遗传变异信息的0、1矩阵,通过运算揭示品种间的遗传关系与演化规律。该方法成本低廉、操作便捷,对于建立客观、科学的牡丹及芍药品种分类体系,对于芍药属品种种质资源的保存、评价与合理利用具有重要价值。应该加大支持力度推进其实际应用。     

不同含水量的豌豆种子萌发时物质动员及代谢研究

不同含水量的豌豆种子在饱和水蒸气中保持7d过程中,含水量低于萌动临界含水量时,子叶中贮藏蛋白质和淀粉的动员不能启动;含水量达到或超过萌动临界含水量,贮藏物质的动员被启动,豌启种子萌动后,子叶中蛋白质和淀动员程度与种子含水量呈正相关,前3d物质动员的程度比后4d强烈得多,因此,含水量是豌豆种子萌发时物质动员的启动因子和调节因子,同时,豌豆种子的含水量直接影响胚轴的生长状况。     

酵母杂交系统的发展及其应用

近年来,酵母单杂交,双杂交及三杂交系统技术的出现及发展已成为分析鉴定蛋白蛋白,DNA蛋白相互作用及调控的强有力工具。本文简述了酵母杂交系统的发展及潜在的应用价值。     

An improved statistical model for taxonomic assignment of metagenomics

Background

With the advances in the next-generation sequencing technologies, researchers can now rapidly examine the composition of samples from humans and their surroundings. To enhance the accuracy of taxonomy assignments in metagenomic samples, we developed a method that allows multiple mismatch probabilities from different genomes.

Results

We extended the algorithm of taxonomic assignment of metagenomic sequence reads (TAMER) by developing an improved method that can set a different mismatch probability for each genome rather than imposing a single parameter for all genomes, thereby obtaining a greater degree of accuracy. This method, which we call TADIP (Taxonomic Assignment of metagenomics based on DIfferent Probabilities), was comprehensively tested in simulated and real datasets. The results support that TADIP improved the performance of TAMER especially in large sample size datasets with high complexity.

Conclusions

TADIP was developed as a statistical model to improve the estimate accuracy of taxonomy assignments. Based on its varying mismatch probability setting and correlated variance matrix setting, its performance was enhanced for high complexity samples when compared with TAMER.

     

Leaf tensity: a method for rapid determination of water requirement information in Brassica napus L.

Water regulation caused by enzymes, such as carbonic anhydrase (CA), changes the water status, making it difficult to diagnose water deficit using leaf water potential (ψ_L) or stomatal conductance (g_s). Therefore, new methods for timely and accurately determining plant water status should be established. In this study, CA activity, ψ_L, leaf tensity (T_d), photosynthetic characteristics and plant growth of Brassica napus L. seedlings under drought and subsequent rewatering were analysed. Results indicated that T_d could reflect the plant water status better than ψ_L or g_s and played an important role in the photosynthesis of B. napus. B. napus exhibited good restorability at the 40?g?L^?1 polyethylene glycol level. The rewatering strategy for B. napus was excellent at 40?g?L^?1 (?0.15?MPa) →20?g?L^?1 (?0.11?MPa). T_d could be used for the rapid determination of water requirement information in B. napus during winter drought period.     

Overexpression of Phytochelatin Synthase in Arabidopsis Leads to Enhanced Arsenic Tolerance and Cadmium Hypersensitivity

The above article appeared in Plant and Cell     

Papillae formation on trichome cell walls requires the function of the mediator complex subunit Med25

Protein phosphatase 2C clade A members are major signaling components in the ABA-dependent signaling cascade that regulates seed germination. To elucidate the role of PP2CA genes in germination of rice seed, we selected OsPP2C51, which shows highly specific expression in the embryo compared with other protein phosphatases based on microarray data. GUS histochemical assay confirmed that OsPP2C51 is expressed in the seed embryo and that this expression pattern is unique compared with those of other OsPP2CA genes. Data obtained from germination assays and alpha-amylase assays of OsPP2C51 knockout and overexpression lines suggest that OsPP2C51 positively regulates seed germination in rice. The expression of alpha-amylase synthesizing genes was high in OsPP2C51 overexpressing plants, suggesting that elevated levels of OsPP2C51 might enhance gene expression related to higher rates of seed germination. Analysis of protein interactions between ABA signaling components showed that OsPP2C51 interacts with OsPYL/RCAR5 in an ABA-dependent manner. Furthermore, interactions were observed between OsPP2C51 and SAPK2, and between OsPP2C51 and OsbZIP10 and we found out that OsPP2C51 can dephosphorylates OsbZIP10. These findings suggest the existence of a new branch in ABA signaling pathway consisting of OsPYL/RCAR-OsPP2C-bZIP apart from the previously reported OsPYL/RCAR-OsPP2C-SAPK-bZIP. Overall, our result suggests that OsPP2C51 is a positive regulator of seed germination by directly suppressing active phosphorylated OsbZIP10.