Project description:we used high-throughput Illumina Genome Analyzer IIx (GAIIx) technology to sequence the small RNA transcriptomes of the mangrove species, Avicennia marina. Based on sequence similarity or the secondary structure of precursors, we have identified 193 conserved miRNAs and 26 novel miRNAs in the small RNA transcriptome of Avicennia marina.
Project description:we used high-throughput Illumina Genome Analyzer IIx (GAIIx) technology to sequence the small RNA transcriptomes of the mangrove species, Avicennia marina. Based on sequence similarity or the secondary structure of precursors, we have identified 193 conserved miRNAs and 26 novel miRNAs in the small RNA transcriptome of Avicennia marina. 1 sample
Project description:Preparation of proteins from salt-gland-enriched tissues of mangrove plant is necessary for a systematic study of proteins involved in the plant’s unique desalination mechanism. Extraction of high-quality proteins from the leaves of mangrove tree species, however, is difficult due to the presence of high levels of endogenous phenolic compounds. In our study, preparation of proteins from only a part of the leaf tissues was required, rendering extraction even more challenging. By comparing several extraction methods, we developed a reliable procedure for obtaining sufficient proteins from salt gland-enriched tissues of the mangrove species Avicennia officinalis. Protein extraction was markedly improved using a phenol-based extraction method. Despite the lower protein yield obtained, one-dimensional protein gel profiles with greater resolution could be obtained, with more than twice the number of proteins detected when 1D-LC-MS/MS analyses were compared. Further analysis of proteins that were solely present in each extraction method favoured the phenol-based extraction. Phenol-based extracts contained nearly 10 times more solely-detected proteins than those were detectable in the extracts without using phenol. The protocol established could thus be applied for downstream high-throughput proteomic analyses involving LC-MS/MS or equivalent.
Project description:We used gel electrophoresis coupled with LC-MS based proteomics to identify key transport proteins in the plasma membrane (PM) and tonoplast fractions of Avicennia officinalis leaves. This was part of our attempts to understand salt tolerance and secretion in mangrove plant species. PM and tonoplast proteins were purified using two-aqueous phase partitioning and density gradient centrifugation, respectively. Thirty of the 154 PM proteins and 31 of the 118 tonoplast proteins identified were predicted to have transmembrane domains. About 90% of the identified proteins could be classified based on their functions. The major classes of proteins were predicted to be involved in transport, metabolic processes, signal transduction and defense /stress response, while a few of the proteins were predicted to be involved in membrane trafficking. The main classes of transporter proteins identified included H+-ATPases, ATP-binding cassette transporters (ABC) and aquaporins, all of which could play a role in salt secretion. These data will serve as the baseline membrane proteomic dataset for Avicennia species. Further, this information can contribute to future studies on understanding the mechanism of salt tolerance in halophytes in addition to salt secretion in mangroves.
Project description:Plant salt glands are nature’s desalination devices that harbour potentially useful information pertaining to salt and water transport during secretion. As part of the program toward deciphering secretion mechanisms in salt glands, we adopted a shotgun approach to look into the proteome of salt-gland enriched tissues of the mangrove tree species Avicennia officinalis. To achieve this, we isolated the adaxial epidermal peels (which harbour the salt glands), and separated them from the mesophyll tissues of the leaves. Three biological replicates were prepared and total proteins were extracted from these tissues. Proteins that were found to be unique in salt gland-enriched tissues were obtained by eliminating proteins found in the mesophyll tissues. The proteins that are uniquely present in salt gland-enriched tissues were then selected and categorized by GO analysis.
Project description:The roots of halophytes such as mangroves provide the first line of defense against the constant salt stress they experience. Such adaptation should include major reprogramming of the gene expression profiles. Using RNA-sequencing approach we identified 101,446 ‘all-unigenes’ from the seedling roots of the mangrove tree Avicennia officinalis. From the data 6618 genes were identified to be differentially regulated by salt when two-month-old greenhouse-grown seedlings without prior exposure to sea water were subjected to 24 h of 500 mM NaCl treatment. About 1,404 genes were significantly up-regulated, while 5214 genes were down-regulated. Based on Gene Ontology analysis, they could be classified under various categories, including metabolic processes, stress and defense response, signal transduction, transcription-related and transporters. Our analysis provides the baseline information towards understanding salt balance in mangroves and hence mechanism of salt tolerance in plants.
Project description:LC-MS/MS M-H(methanol: water 7/3) and MET (methanol) leaves and stems extracts of Rhizophora mangle, Avicennia schaueriana and Laguncularia racemosa from Paripe river mangrove - Ceara, Brazil.
Project description:Environmental variation along the geographical space can shape populations by natural selection. In the context of global warming and changing precipitation regimes, it is crucial to understand the role of environmental heterogeneity in tropical trees adaptation, given their disproportional contribution to water and carbon biogeochemical cycles. Here, we investigated how heterogeneity in freshwater availability along tropical wetlands has influenced molecular variations of the black mangrove (Avicennia germinans). A total of 57 trees were sampled at seven sites differing markedly in precipitation regime and riverine freshwater inputs. Using 2,297 genome‐wide single nucleotide polymorphic markers, we found signatures of natural selection by the association between variations in allele frequencies and environmental variables, including the precipitation of the warmest quarter and the annual precipitation. Additionally, we found candidate loci for selection based on statistical deviations from neutral expectations of interpopulation differentiation. Most candidate loci within transcribed sequences were functionally associated with central aspects of drought tolerance or plant response to drought. Moreover, our results suggest the occurrence of the rapid evolution of a population, probably in response to sudden and persistent limitations in plant access to soil water, following a road construction in 1974. Observations supporting rapid evolution included the reduction in tree size and changes in allele frequencies and in transcript expression associated with increased drought tolerance through the accumulation of osmoprotectants and antioxidants, biosynthesis of cuticles, protection against protein degradation, stomatal closure, photorespiration and photosynthesis. We describe a major role of spatial heterogeneity in freshwater availability in the specialization of this typically tropical tree.
2020-05-15 | GSE123659 | GEO
Project description:Seasonal comparison of bacterial communities in an arid Avicennia marina mangrove forest