白玉兰播种苗年生长规律的研究

本文通过对白玉兰一年生播种苗年生长进程的研究,阐明了苗高、地径的年变化规律,并拟合其生长模型,从而为生产上有效采取育苗措施提供科学依据．     

Epigenetic regulation of <Emphasis Type="Italic">MdMYB1</Emphasis> is associated with paper bagging-induced red pigmentation of apples

Main conclusion

Paper-bagging treatment can transform non-transcribed MdMYB1 - 2 and MdMYB1 - 3 alleles into transcribed alleles through epigenetic regulations, resulting in the red pigmentation of a normally non-red apple cultivar ‘Mutsu.’ Anthocyanin biosynthesis in apples is regulated by MdMYB1/A/10, an R2R3-Type MYB gene. ‘Mutsu,’ a triploid apple cultivar harboring non-transcribed MdMYB1-2 and MdMYB1-3 alleles, retains green skin color under field conditions. However, it can show red/pink pigmentation under natural or artificial ultraviolet-B (UV-B) light exposure after paper-bagging and bag removal treatment. In the present study, we found that in ‘Mutsu,’ paper bagging-induced red pigmentation was due to the activation of non-transcribed MdMYB1-2/-3 alleles, which triggered the expression of downstream anthocyanin biosynthesis genes in a UV-B-dependent manner. By monitoring the epigenetic changes during UV-B-induced pigmentation, no significant differences in DNA methylation and histone modifications in the 5′ upstream region of MdMYB1-2/-3 were recorded between the UV-B-treated fruit skin (red) and the fruit skin treated only by white light (green). In contrast, bag treatment lowered the DNA methylation in this region of MdMYB1-2/-3 alleles. Similarly, higher levels of histone H3 acetylation and trimethylation of H3 tail at lysine 4, and lower level of trimethylation of H3 tail at lysine 27 were observed in the 5′ upstream region of MdMYB1-2/-3 in the skin of the fruit immediately after bag removal. These results suggest that bagging treatment can induce epigenetic changes, facilitating the binding of trans factor(s) to MdMYB1-2/-3 alleles, resulting in the activation of these MYBs after bag removal.

     

不同水分条件下春小麦种群中个体大小不整齐性及遗传学分析不同水分条件下春小麦种群中个体大小不整齐性及遗传学分析

 种群内个体大小不整齐性是种群数量结构的主要指标。本文研究了不同水分条件下,3个品种春小麦种群个体大小不整齐性的建立及变化规律。对春小麦种群不整齐性的遗传学分析表明：遗传结构与随机环境修饰对种群数量结构形成的相对重要性,因水分条件不同而异。种群不整齐性在自然选择中的作用可用下列简单模型表示：CSo＝SH×hSH2 CSo：自然选择强度;SH：大小不整齐性;hSH2：不整齐性的遗传力。     

STUDY ON XORIDES (MOEROPHORA) (HYMENOPTERA: ICHNEU-MONIDAE) FROM NORTHEASTERN CHINA

Abstract  Two species of Xorides ( Moerophora ) collected in the northeastern part of China, in which one is new to science, namely Xorides ( Moerophora ) tuqiangensis Sheng sp. nov., and one, X . ( M .) jakovlevi (Kokujev) 1903, is a Chinese new record, are reported. A key is provided to distinguish the Chinese species of this subgenus.     

Effect of Pre-Stressing on the Acid-Stress Response in Bifidobacterium Revealed Using Proteomic and Physiological Approaches

Weak acid resistance limits the application of Bifidobacteria as a probiotic in food. The acid tolerance response (ATR), caused by pre-stressing cells at a sublethal pH, could improve the acid resistance of Bifidobacteria to subsequent acid stress. In this study, we used Bifidobacterium longum sub. longum BBMN68 to investigate the effect of the ATR on the acid stress response (ASR), and compared the difference between the ATR and the ASR by analyzing the two-dimensional-PAGE protein profiles and performing physiological tests. The results revealed that a greater abundance of proteins involved in carbohydrate metabolism and protein protection was present after the ASR than after the ATR in Bifidobacterium. Pre-stressing cells increased the abundance of proteins involved in energy production, amino acid metabolism, and peptidoglycan synthesis during the ASR of Bifidobacterium. Moreover, after the ASR, the content of ATP, NH₃, thiols, and peptidoglycan, the activity of H⁺-ATPase, and the maintenance of the intracellular pH in the pre-stressed Bifidobacterium cells was significantly higher than in the uninduced cells. These results provide the first explanation as to why the resistance of Bifidobacterium to acid stress improved after pre-stressing.     

MicroRNA-21 promotes wound healing via the Smad7-Smad2/3-Elastin pathway

Wound healing is regulated by a complex network of cells, molecules, and cytokines, as well as microRNAs (miRNAs). miRNAs were confirmed to influence the wound healing process, and miR-21, an important member of the miRNA family, was also shown to regulate wound healing. The aim of the present study was to investigate the role of miR-21 in the wound healing process and the possible underlying cell signaling pathways. We isolated GMSCs from WT and miR-21-KO mouse gingiva. Flow cytometric analysis and immunocytofluorescense staining were used to identify the GMSCs acquired from WT and miR-21-KO mice. RT-PCR, western blot analysis and immunohistofluorescence staining were performed to examine the expression of extracellular matrix components and key proteins of cell signaling pathways. TargetScan and pmiR-RB-REPORT vectors were used to verify that Smad7 was a direct target of miR-21. Compared to WT mice, miR-21-KO mice showed slower wound healing. RT-PCR and western blot analysis indicated that Elastin expression was downregulated in miR-21-deficient samples. We confirmed that Smad7 was a direct target of miR-21. miR-21 knockout resulted in increased expression of Smad7 and impaired phosphorylation of the Smad2/3 complex. The expression of the Smad7-Smad2/3-Elastin axis in palate tissues sections acquired from WT and miR-21-KO mice showed the same trend. Based on all these results, we demonstrated that miR-21 promoted the wound healing process via the Smad7-Smad2/3-Elastin pathway.     

Knockdown of Carotenoid Cleavage Dioxygenase 4 (CCD4) via Virus-Induced Gene Silencing Confers Yellow Coloration in Peach Fruit: Evaluation of Gene Function Related to Fruit Traits

Plant Molecular Biology Reporter - Transgenic approach is an excellent way for the clarification of gene function, but it is generally difficult to create transgenic plants for most of the fruit...     

土壤水分亏缺对春小麦根系干物质累积和分配的影响

在人工气候室中进行实验,实施光、温自动控制,研究了土壤水分对春小麦根系干物质积累和分配的影响,３个处理是春小科整个生长发育期内土壤水分分别控制在田间持水量的３０％,６０％,９０％,实验结果表明,在四叶一心－抽穗开花期间,３个处理气孔阻力逐渐降低,光合速率蒸腾速度逐渐上升,其中,中等水分条件下蒸腾速率明显低于充分供水,而光合速率则接近或显著高于是。抽一开花期,下层以根长,根竽中等水分处理显著高于其余     

Quantifying sequence and structural features of protein–RNA interactions

Increasing awareness of the importance of protein–RNA interactions has motivated many approaches to predict residue-level RNA binding sites in proteins based on sequence or structural characteristics. Sequence-based predictors are usually high in sensitivity but low in specificity; conversely structure-based predictors tend to have high specificity, but lower sensitivity. Here we quantified the contribution of both sequence- and structure-based features as indicators of RNA-binding propensity using a machine-learning approach. In order to capture structural information for proteins without a known structure, we used homology modeling to extract the relevant structural features. Several novel and modified features enhanced the accuracy of residue-level RNA-binding propensity beyond what has been reported previously, including by meta-prediction servers. These features include: hidden Markov model-based evolutionary conservation, surface deformations based on the Laplacian norm formalism, and relative solvent accessibility partitioned into backbone and side chain contributions. We constructed a web server called aaRNA that implements the proposed method and demonstrate its use in identifying putative RNA binding sites.