Endogenous abscisic acid signaling towards storage reserve filling in developing seed tissues of castor bean (Ricinus communis L.)

Abscisic acid (ABA; free form) is a naturally occurring physiological growth hormone of higher plants. A detailed study involving the time course growth of developing seed tissues associated with endogenous levels of free ABA were investigated using a novel enzyme-linked immunosorbent assay. Seed filling in castor (Ricinuc communis L.) endosperm, embryo, and pod is marked with a rapid increase in fresh weight during the mid-developmental stages [21–42 days after pollination (DAP)], followed by a steady decline at the maturation stages (42–63 DAP) accompanied with a rapid lipid synthesis (in endosperm and embryo) during the same period, except for in pod. Endogenous ABA levels in endosperm (0.001–0.32 μg/g) and embryo (0.003–0.13 μg/g) followed a concurrent pattern with seed reserve filling, showing a rapid increase during the mid-developmental stages 21–42 DAP, whereas ABA levels in seed pod (0.2–22.9 μg/g) showed a different accumulation pattern with rapid increase and decline during the early-mid developmental stages, preceded by the maximal increase during the maturation stage (63 DAP). Together, our results provide evidence for the association of endogenous ABA in seed filling as well as in reserve deposition and provides clue for the effective usage of exogenous ABA concentrations in developing seeds with a focus, on improving seed reserve complex in castor.     

Comparing interfacial dynamics in protein-protein complexes: an elastic network approach

Background  

The transient, or permanent, association of proteins to form organized complexes is one of the most common mechanisms of regulation of biological processes. Systematic physico-chemical studies of the binding interfaces have previously shown that a key mechanism for the formation/stabilization of dimers is the steric and chemical complementarity of the two semi-interfaces. The role of the fluctuation dynamics at the interface of the interacting subunits, although expectedly important, proved more elusive to characterize. The aim of the present computational study is to gain insight into salient dynamics-based aspects of protein-protein interfaces.     

Comparative proteomic analysis and characterization of benzo(a)pyrene removal by Microbacterium sp. strain M.CSW3 under denitrifying conditions

Bioprocess and Biosystems Engineering - High-molecular-weight polycyclic aromatic hydrocarbons are persistent organic pollutants with great environmental and human health risks and the associated...     

桑树激光育种方法的研究

激光应用于桑树育种起于七十年代,通过我所二十多年来对桑树激光育种方法的研究与探讨,激光对桑树营养器官和生殖器官都可产生生物学效应,但这种效应的大小,多少与供试材料,供试品种和激光种类,功率大小有关,而且激光较电离辐射有它独特的优点。实践证明,激光育种与杂交育种相结合,或激光与其它理化因素相结合,处理桑树的无性器官冬芽能产生较多的有益突变,为桑树激光育种的最佳途径。     

iTRAQ-based proteomic profiling of a Microbacterium sp. strain during benzo(a)pyrene removal under anaerobic conditions

This study focused on the protein expression of a Microbacterium sp. strain that utilized various concentrations of benzo(a)pyrene (BaP) as the sole source of carbon and energy under anaerobic conditions. A total of 1539 protein species were quantified by isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS. GO, COG, and pathway enrichment analysis showed that most proteins demonstrated catalytic and binding functions and were mainly involved in metabolic processes, cellular processes, and single-organism processes. Sixty-two proteins were found in their abundances in BaP-stress conditions different from normal conditions. These proteins function in the metabolic pathways; the biosynthesis of secondary metabolites, the biosynthesis of antibiotics, microbial metabolism in diverse environments, carbon metabolism, and the biosynthesis of amino acids were markedly altered. Furthermore, enoyl-CoA hydratase was proposed to be a key protein during BaP removal of the Microbacterium sp. strain. This study provides a powerful platform for the further exploration of BaP removal, and the differentially expressed proteins provide insight into the mechanism of the BaP removal pathway.

     

矮牵牛花色基因工程研究进展

矮牵牛花色素苷生物合成过程中至少有12种酶参与,除了AAT、AMT之外的大多数相关合成酶结构基因已经被克隆,调节基因An2、An4及酶活性调节基因difF也先后从矮牵牛中分离出来.多种花色基因如DFR、F3'5'H、CHS、CHI、CHR、Lc等转化矮牵牛都能影响花色,外源CHS导入还会引起雄性不育.该文主要对近年来国内外有关矮牵牛花色相关基因的分离、应用及外源基因转入三方面的研究进展进行综述,并对矮牵牛花色基因工程研究的应用前景进行了讨论.     

MicroRNA-23a/b and microRNA-27a/b suppress Apaf-1 protein and alleviate hypoxia-induced neuronal apoptosis

Expression of apoptotic protease activating factor-1 (Apaf-1) gradually decreases during brain development, and this decrease is likely responsible for the decreased sensitivity of brain tissue to apoptosis. However, the mechanism by which Apaf-1 expression is decreased remains elusive. In the present study, we found that four microRNAs (miR-23a/b and miR-27a/b) of miR-23a-27a-24 and miR-23b-27b-24 clusters play key roles in modulating the expression of Apaf-1. First, we found that miR-23a/b and miR-27a/b suppressed the expression of Apaf-1 in vitro. Interestingly, the expression of the miR-23-27-24 clusters in the mouse cortex gradually increased in a manner that was inversely correlated with the pattern of Apaf-1 expression. Second, hypoxic injuries during fetal distress caused reduced expression of the miR-23b and miR-27b that was inversely correlated with an elevation of Apaf-1 expression during neuronal apoptosis. Third, we made neuronal-specific transgenic mice and found that overexpressing the miR-23b and miR-27b in mouse neurons inhibited the neuronal apoptosis induced by intrauterine hypoxia. In conclusion, our results demonstrate, in central neural system, that miR-23a/b and miR-27a/b are endogenous inhibitory factors of Apaf-1 expression and regulate the sensitivity of neurons to apoptosis. Our findings may also have implications for the potential target role of microRNAs in the treatment of neuronal apoptosis-related diseases.