Redox proteomics of tomato in response to Pseudomonas syringae infection

Unlike mammals with adaptive immunity,plants rely on their innate immunity based on pattern-triggered immunity(PTI)and effector-triggered immunity(ETI)for pathogen defense.Reactive oxygen species,known to play crucial roles in PTI and ETI,can perturb cellular redox homeostasis and lead to changes of redox-sensitive proteins through modification of cysteine sulfhydryl groups.Although redox regulation of protein functions has emerged as an important mechanism in several biological processes,little is known about redox proteins and how they function in PTI and ETI.In this study,cysTMT proteomics technology was used to identify similarities and differences of protein redox modifications in tomato resistant(PtoR)and susceptible(prf3)genotypes in response to Pseudomonas syringae pv tomato(Pst)infection.In addition,the results of the redox changes were compared and corrected with the protein level changes.A total of 90 potential redox-regulated proteins were identified with functions in carbohydrate and energy metabolism,biosynthesis of cysteine,sucrose and brassinosteroid,cell wall biogenesis,polysaccharide/starch biosynthesis,cuticle development,lipid metabolism,proteolysis,tricarboxylic acid cycle,protein targeting to vacuole,and oxidation–reduction.This inventory of previously unknown protein redox switches in tomato pathogen defense lays a foundation for future research toward understanding the biological significance of protein redox modifications in plant defense responses.

Regulation of D-galacturonate metabolism in <i>Caulobacter crescentus</i>by HumR, a LacI-family transcriptional repressor

The oligotrophic freshwater bacterium Caulobacter crescentus encodes a cluster of genes (CC_1487 to CC_1495) shown here to be necessary for metabolism of D-galacturonate, the primary constituent of pectin, a major plant polymer. Sequence analysis suggests that these genes encode a version of the bacterial hexuronate isomerase pathway. A conserved 14 bp sequence motif is associated with promoter regions of three operons within this cluster, and is conserved in homologous gene clusters in related alpha-Proteobacteria. Embedded in the hexuronate gene cluster is a gene (CC_1489) encoding a member of the LacI family of bacterial transcription factors. This gene product, designated here as HumR (hexuronate metabolism regulator), represses expression of the uxaA and uxaC operon promoters by binding to the conserved operator sequence. Repression is relieved in the presence of galacturonate or, to a lesser extent, by glucuronate. Other genes potentially involved in pectin degradation and hexuronate transport are also under the control of HumR. Adoption of a LacI-type repressor to control hexuronate metabolism parallels the regulation of xylose, glucose, and maltose utilization in C. crescentus, but is distinct from the use of GntR-type repressors to control pectin and hexuronate utilization in gamma-Proteobacteria such as Escherichia coli.

母亲颗粒物空气污染暴露与足月出生体重:效应与异质性的多国评估

[背景]越来越多的证据显示,母亲空气污染暴露与对胎儿生长的不良影响之间存在关联;但是,现有的文献并不一致。[目的]研究9个国家14个中心的数据,量化母亲颗粒物空气污染暴露与足月出生体重和低出生体重(LBW)之间的关联,并探讨此关联中地点特征和暴露评估方法对中心之间异质性的影响。[方法]空气污染与妊娠结局国际合作(ICAPPO)的各中心采用共同的分析方案,对PM10和PM2.5(颗粒物≤10和2.5μm)与足月LBW和连续出生体重进行效应评估。采用meta分析将各个中心(~300万例出生)的效应评估结合起来,并采用meta回归分析在报告的效应评估中,中心特征和暴露评估方法对中心之间异质性的影响。[结果]随机效应meta分析显示,调整母亲的社会经济地位后,在整个妊娠期间,足月LBW与PM10[比值比(OR)=1.03;95%CI:1.01~1.05]和PM2.5[OR=1.10;95%CI:1.03~1.18]每增加10μg/m3呈正相关。在充分调整随机效应的meta分析中,作为一个连续性的结果,PM10暴露每增加10μg/m3与足月出生体重呈负相关(-8.9g;95%CI:-13.2^-4.6 g)。meta回归分析显示,具有较高平均PM2.5水平和PM2.5∶PM10比率的中心,以及采用时间暴露评估(与时空相比)的中心,所报告的关联更强。[结论]在研究人群中,母亲颗粒物污染暴露与足月LBW相关联。有3个地点特征和暴露评估方法学方面的不同导致各个中心报告的关联的差异。

这个七月关于法罗群岛的一切

法罗群岛是一个偏远而迷人的群岛,由18块巨大的火山玄武岩构成,它们穿越挪威和冰岛中间的北大西洋,尖尖的山体直指天空。最初,挪威维京人在公元九、十世纪于此占据,如今这里是丹麦王国的一块自治领地,也是徒步旅行者、登山者和羊的天堂。这里生活着8万只这种毛茸茸的食草动物,相比之下,居民只有5万人。这些草场茂盛和相对不为人知的原生态自然岛屿,还没有成为人满为患的旅游景点。但情况可能正在改变。