Comparative transcriptome investigation of global gene expression changes caused by miR156 overexpression in Medicago sativa

Nucleotide sequences alignment between (a) M. sativa SPL2/3/4 and Arabidopsis SPL3/4/5; (b) MsSPL9 and AtSPL9, respectively. (TIF 3681 kb

Mercury in the marine environment of the Canadian Arctic: Review of recent findings

AbstractThis review summarizes data and information which have been generated on mercury (Hg) in the marine environment of the Canadian Arctic since the previous Canadian Arctic Contaminants Assessment Report (CACAR) was released in 2003. Much new information has been collected on Hg concentrations in marine water, snow and ice in the Canadian Arctic. The first measurements of methylation rates in Arctic seawater indicate that the water column is an important site for Hg methylation. Arctic marine waters were also found to be a substantial source of gaseous Hg to the atmosphere during the ice-free season. High Hg concentrations have been found in marine snow as a result of deposition following atmospheric mercury depletion events, although much of this Hg is photoreduced and re-emitted back to the atmosphere. The most extensive sampling of marine sediments in the Canadian Arctic was carried out in Hudson Bay where sediment total Hg (THg) concentrations were low compared with other marine regions in the circumpolar Arctic. Mass balance models have been developed to provide quantitative estimates of THg fluxes into and out of the Arctic Ocean and Hudson Bay.Several recent studies on Hg biomagnification have improved our understanding of trophic transfer of Hg through marine food webs. Over the past several decades, Hg concentrations have increased in some marine biota, while other populations showed no temporal change. Marine biota also exhibited considerable geographic variation in Hg concentrations with ringed seals, beluga and polar bears from the Beaufort Sea region having higher Hg concentrations compared with other parts of the Canadian Arctic. The drivers of these variable patterns of Hg bioaccumulation, both regionally and temporally, within the Canadian Arctic remain unclear. Further research is needed to identify the underlying processes including the interplay between biogeochemical and food web processes and climate change

Cynanchum sublanceolatum Matsum.

原著和名: コバノカモメヅル科名: ガガイモ科 = Asclepiadaceae採集地: 千葉県 佐倉市 飯重 (下総 佐倉市 飯重)採集日: 1988/10/15採集者: 萩庭丈壽整理番号: JH004782国立科学博物館整理番号: TNS-VS-95478

Additional file 4: Figure S1. of Comparative transcriptome investigation of global gene expression changes caused by miR156 overexpression in Medicago sativa

A representation of the conserved SBP domain (nucleotides) from the genes included in the phylogenetic tree using WebLogo. (TIF 485 kb

Additional file 3: Table S3. of Comparative transcriptome investigation of global gene expression changes caused by miR156 overexpression in Medicago sativa

Full list of the components included in cellular component, biological process and molecular function. The full list of the GO terms that correspond to the differentially expressed genes in two genotypes of miR156OE alfalfa plants compared to WT. (XLSX 16 kb

COP9 signalosome subunit 5A affects phenylpropanoid metabolism, trichome formation and transcription of key genes of a regulatory tri-protein complex in Arabidopsis

Abstract Background Trichomes and phenylpropanoid-derived phenolics are structural and chemical protection against many adverse conditions. Their production is regulated by a network that includes a TTG1/bHLH/MYB tri-protein complex in Arabidopsis. CSN5a, encoding COP9 signalosome subunit 5a, has also been implicated in trichome and anthocyanin production; however, the regulatory roles of CSN5a in the processes through interaction with the tri-protein complex has yet to be investigated. Results In this study, a new csn5a mutant, sk372, was recovered based on its altered morphological and chemical phenotypes compared to wild-type control. Mutant characterization was conducted with an emphasis on trichome and phenylpropanoid production and possible involvement of the tri-protein complex using metabolite and gene transcription profiling and scanning electron microscopy. Seed metabolite analysis revealed that defective CSN5a led to an enhanced production of many compounds in addition to anthocyanin, most notably phenylpropanoids and carotenoids as well as a glycoside of zeatin. Consistent changes in carotenoids and anthocyanin were also found in the sk372 leaves. In addition, 370 genes were differentially expressed in 10-day old seedlings of sk372 compared to its wild type control. Real-time transcript quantitative analysis showed that in sk372, GL2 and tri-protein complex gene TT2 was significantly suppressed (p  0.05). Complex genes MYB75, GL1 and flavonoid biosynthetic genes TT3 and TT18 in sk372 were all significantly enhanced. Overexpression of GL3 driven by cauliflower mosaic virus 35S promotor increased the number of single pointed trichomes only, no other phenotypic recovery in sk372. Conclusions Our results indicated clearly that COP9 signalosome subunit CSN5a affects trichome production and the metabolism of a wide range of phenylpropanoid and carotenoid compounds. Enhanced anthocyanin accumulation and reduced trichome production were related to the enhanced MYB75 and suppressed GL2 and some other differentially expressed genes associated with the TTG1/bHLH/MYB complexes

Additional file 2: Table S2. of Comparative transcriptome investigation of global gene expression changes caused by miR156 overexpression in Medicago sativa

Differentially expressed genes with significant fold change detected between WT and two miR156OE genotypes (A11and A17). Differentially expressed genes between WT and the two miR156OE genotypes A11a and A17. (XLSX 1067 kb