Understanding the genetic basis of local adaptation is challenging due to the subtle balance among conflicting evolutionary forces that are involved in its establishment and maintenance. One system with which to tease apart these difficulties is clines in adaptive characters. Here we analyzed genetic and phenotypic variation in bud set, a highly heritable and adaptive trait, among 18 populations of Norway spruce (Picea abies), arrayed along a latitudinal gradient ranging from 47°N to 68°N. We confirmed that variation in bud set is strongly clinal, using a subset of five populations. Genotypes for 137 single-nucleotide polymorphisms (SNPs) chosen from 18 candidate genes putatively affecting bud set and 308 control SNPs chosen from 264 random genes were analyzed for patterns of genetic structure and correlation to environment. Population genetic structure was low (F ST ¼ 0.05), but latitudinal patterns were apparent among Scandinavian populations. Hence, part of the observed clinal variation should be attributable to population demography. Conditional on patterns of genetic structure, there was enrichment of SNPs within candidate genes for correlations with latitude. Twenty-nine SNPs were also outliers with respect to F ST . The enrichment for clinal variation at SNPs within candidate genes (i.e., SNPs in PaGI, PaPhyP, PaPhyN, PaPRR7, and PaFTL2) indicated that local selection in the 18 populations, and/or selection in the ancestral populations from which they were recently derived, shaped the observed cline. Validation of these genes using expression studies also revealed that PaFTL2 expression is significantly associated with latitude, thereby confirming the central role played by this gene in the control of phenology in plants.L OCAL adaptation is a key process in the evolution of species. Understanding how local adaptation is established and maintained, however, is especially difficult as its establishment is contingent upon historical conditions and its maintenance depends on the balance among conflicting evolutionary forces (e.g., Yeaman and Otto 2011). It is a particularly challenging task in forest trees, because they have long generation times and therefore cannot be easily manipulated experimentally. For instance, transfer experiments are theoretically possible but practically difficult to implement. On the other hand, the analysis of the strong latitudinal clines displayed by forest trees for potentially adaptive traits such as bud set (Dormling 1973;Savolainen et al. 2007;Aitken et al. 2008) can provide crucial information on the forces involved in local adaptation and, in particular, on the relative parts played by demography and selection in the establishment of the cline. Furthermore, phenology in general, and flowering time and bud set in particular, have been extensively studied and strong candidate genes are available, many of which belong to the photoperiodic pathway including the circadian clock (Gyllenstrand et al. 2007;Albani and Coupland 2010;Bergelson and Roux 2010;Fornara et al. 2...

Perennial plants monitor seasonal changes through changes in environmental conditions such as the quantity and quality of light. To ensure a correct initiation of critical developmental processes, such as the initiation and cessation of growth, plants have adapted to a spatially variable light regime and genes in the photoperiodic pathway have been implicated as likely sources for these adaptations. Here we examine genetic variation in genes from the photoperiodic pathway in Populus tremula (Salicaceae) for signatures diversifying selection in response to varying light regimes across a latitudinal gradient. We fail to identify any loci with unusually high levels of genetic differentiation among populations despite identifying four SNPs that show significant allele frequency clines with latitude. We do, however, observe large covariance in allelic effects across populations for growth cessation, a highly adaptive trait in P.tremula. High covariance in allelic effects is a signature compatible with diversifying selection along an environmental gradient. We also observe significantly higher heterogeneity in genetic differentiation among SNPs from the photoperiod genes than among SNPs from randomly chosen genes. This suggests that spatially variable selection could be affecting genes from the photoperiod pathway even if selection is not strong enough to cause individual loci to be identified as outliers. SNPs from three genes in the photoperiod pathway (PHYB2, LHY1, and LHY2) show significant associations with natural variation in growth cessation. Collectively these SNPs explain 10-15% of the phenotypic variation in growth cessation. Covariances in allelic effects across populations help explain an additional 5-7% of the phenotypic variation in growth cessation.

Streptococcus pyogenes of the M1 serotype can cause streptococcal toxic shock syndrome commonly associated with acute lung injury. The aim of the present study was to investigate the role of neutrophils and their secretion products in M1 protein-induced lung damage.The degranulation of neutrophils by M1 protein was studied in whole blood using marker analysis for individual granule subsets. In mice, M1 protein was injected intravenously and the lung damage was assessed by histology, electron microscopy, cell count in bronchoalveolar lavage fluid and analysis of lung vascular permeability. Comparisons were made in mice with intact white blood count, neutropenic mice and neutropenic mice injected with the secretion of activated neutrophils.In whole blood, M1 protein forms complexes with fibrinogen that bind to b 2 -integrins on the neutrophil surface, resulting in degranulation of all four subsets of neutrophil granules. Intravenous injection of M1 protein into mice induced neutrophil accumulation in the lung, increase in vascular permeability and acute lung damage. Depletion of neutrophils from the circulation completely abrogated lung injury and vascular leakage. Interestingly, the lung damage was restored by injecting neutrophil secretion.The present data suggest that neutrophil granule proteins are directly responsible for lung damage induced by the streptococcal M1 protein.

A consensus linkage map of Picea abies, an economically important conifer, was constructed based on the segregation of 686 SNP markers in a F1 progeny population consisting of 247 individuals. The total length of 1889.2 cM covered 96.5% of the estimated genome length and comprised 12 large linkage groups, corresponding to the number of haploid P. abies chromosomes. The sizes of the groups (from 5.9 to 9.9% of the total map length) correlated well with previous estimates of chromosome sizes (from 5.8 to 10.8% of total genome size). Any locus in the genome has a 97% probability to be within 10 cM from a mapped marker, which makes the map suited for QTL mapping. Infecting the progeny trees with the root rot pathogen Heterobasidion parviporum allowed for mapping of four different resistance traits: lesion length at the inoculation site, fungal spread within the sapwood, exclusion of the pathogen from the host after initial infection, and ability to prevent the infection from establishing at all. These four traits were associated with two, four, four and three QTL regions respectively of which none overlapped between the traits. Each QTL explained between 4.6 and 10.1% of the respective traits phenotypic variation. Although the QTL regions contain many more genes than the ones represented by the SNP markers, at least four markers within the confidence intervals originated from genes with known function in conifer defence; a leucoanthocyanidine reductase, which has previously been shown to upregulate during H. parviporum infection, and three intermediates of the lignification process; a hydroxycinnamoyl CoA shikimate/quinate hydroxycinnamoyltransferase, a 4-coumarate CoA ligase, and a R2R3-MYB transcription factor.

Background Reaumuria soongorica is an extreme xerophyte shrub widely distributed in the desert regions including sand dune, Gobi and marginal loess of central Asia which plays a crucial role to sustain and restore fragile desert ecosystems. However, due to the lacking of the genomic sequences, studies on R. soongorica had mainly limited in physiological responses to drought stress. Here, a deep transcriptomic sequencing of R. soongorica will facilitate molecular functional studies and pave the path to understand drought adaptation for a desert plant.Methodology/Principal FindingsA total of 53,193,660 clean paired-end reads was generated from the Illumina HiSeq™ 2000 platform. By assembly with Trinity, we got 173,700 contigs and 77,647 unigenes with mean length of 677 bp and N50 of 1109 bp. Over 55% (43,054) unigenes were successfully annotated based on sequence similarity against public databases as well as Rfam and Pfam database. Local BLAST and Kyoto Encyclopedia of Genes and Genomes (KEGG) maps were used to further exhausting seek for candidate genes related to drought adaptation and a set of 123 putative candidate genes were identified. Moreover, all the C4 photosynthesis genes existed and were active in R. soongorica, which has been regarded as a typical C3 plant.Conclusion/SignificanceThe assembled unigenes in present work provide abundant genomic information for the functional assignments in an extreme xerophyte R. soongorica, and will help us exploit the genetic basis of how desert plants adapt to drought environment in the near future.

Past geological and climatic events have promoted intraspecific divergence and range shifts in numerous plant species. This is particularly true for temperate species in climate-sensitive regions. Few previous studies have examined whether such genetic footprints were also shaped in desert plants, which can survive in arid habitats and might be "static" under the past climatic oscillations. We therefore studied the phylogeographical history of Reaumuria soongarica, a shrub species that is widely distributed across the deserts of western China. We sequenced chloroplast DNA (cpDNA) fragments of 27 natural populations across western China. Eight cpDNA haplotypes were identified, which clustered into three clades. The clades were located in the western (clade II) or eastern regions (clades I and III) of western China. Analysis of molecular variance also supported this major partitioning (∼67%) of the cpDNA variation between regions. However, within each region, genetic differentiation was low (29%-37%) and a single dominant haplotype was fixed; this indicated past regional range expansion. The deep divergence and regional range expansions of this species may have corresponded to the most recent uplift of the Qinghai-Tibet Plateau and the development of desert ecosystems during the last glacial age in western China. This is the first study to show that the evolutionary history of plants in desert habitats has been seriously affected by past geological and climatic change.

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Acute lung injury (ALI) is a life-threatening inflammatory disease owing to the lack of specific and effective therapies. Oridonin (Ori) is an active diterpenoid isolated from Rabdosiarubescens (R.rubescens) that has been shown to possess a broadspectrum pharmacological properties including anti-inflammatory, antitumour, antioxidative and neuroregulatory effects. However, its potential protective mechanism in ALI is not well characterized. In this study, we demonstrated that Ori reduces the mortality of mice with ALI induced by a high dose of lipopolysaccharide (LPS), which suggests that Ori has a protective effect on LPS induced ALI. Next, our results confirmed that Ori improves LPS-induced localized pulmonary pathology and decreased the concentration of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in the serum. Nuclear factor-kappa B (NF-κB) is capable of regulating the transcription of pro-inflammatory factors. Interestingly, our results showed that Ori inhibits the expression of TLR4/MyD88 and phosphorylation of NF-κB p65 in lung tissues. To confirm this, we further validated the possible regulatory anti-inflammatory mechanisms of Ori in vitro. LPS-induced RAW264.7 cells, which are widely used as an inflammation model to evaluate the potential protective effect of drugs in vitro, were chosen for this study. Similar results were observed, that is, pre-treatment with Ori, markedly inhibited the nuclear translocation and phosphorylation of NF-κB p65 induced by LPS and subsequently decreased the release of pro-inflammatory cytokines that were increased by LPS. Overall, these results demonstrated that Ori exerts a therapeutic effect on ALI by inhibiting the release of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, through the TLR4/MyD88/NF-κB axis.