Project description:Global warming has shifted climate zones poleward or upward. However, understanding the responses and mechanism of microbial community structure and functions relevant to natural climate zone succession is challenged by the high complexity of microbial communities. Here, we examined soil microbial community in three broadleaved forests located in the Wulu Mountain (WLM, temperate climate), Funiu Mountain (FNM, at the border of temperate and subtropical climate zones), or Shennongjia Mountain (SNJ, subtropical climate).Soils were characterized for geochemistry, Illumina sequencing was used to determine microbial taxonomic communities and GeoChips 5.0 were used to determine microbial functional genes.
Project description:Anthropogenic nutrient inputs alter soil biodiversity; however, it remains largely unknown whether changes in soil microeukaryotes (fungi and protists) are primarily driven by direct effects, such as modifications in soil properties, or by indirect effects, such as plant diversity loss. To disentangle these mechanisms, we investigated the long-term effects (11 years) of fertilization and manipulated plant diversity (1, 2, or 4 plant species) on soil microeukaryote communities in a temperate grassland experiment using long-amplicon rRNA sequencing. Our results indicate that fertilization generally had a stronger influence on microeukaryote communities than plant species richness. Fertilization altered the community composition of fungi and protists, increased OTU richness by 20.8% and 52.7%, respectively, and shifted community dominance from fungi to protists. Regarding plant diversity, we observed an effect exclusively on the protist community. Changes were primarily explained by increased plant biomass (driven by both fertilization and plant diversity) and by higher soil phosphorus and lower soil pH levels (driven exclusively by fertilization). Regarding life strategies, we observed synergistic treatment effects: fertilization primarily enhanced fungal saprophytes (only richness), fungal animal pathogens, and protist consumers, whereas plant diversity affected phototrophic protists (reduction) and protist animal pathogens (enhancement). Notably, fertilization and plant diversity decline together led to a cumulative increase in fungal plant pathogens. In conclusion, we highlight that fertilisation alone has a significant effect on soil microeukaryotes, while the additional decline in plant diversity affects different soil groups that are not directly affected by fertilisation. This synergistic pattern indicates that fertilization can influence the entire microeukaryote community through direct and indirect mechanisms, with a cumulative enhancement on certain groups, such as plant pathogens.
Project description:Land cover change has long been recognized that marked effect the amount of soil organic carbon. However, little is known about microbial-mediated effect processes and mechanism on soil organic carbon. In this study, the soil samples in a degenerated succession from alpine meadow to alpine steppe meadow in Qinghai-Tibetan Plateau degenerated, were analyzed by using GeoChip functional gene arrays.
Project description:Sago palm is an important agricultural starch producing plant which contributes to the economics of Malaysia where the trunk is the main plant part which the starch is stored. However, there are sago palms that planted on peat soil failed to develop its trunk even after 17 years been planted. This phenomenon is known as 'non-trunking', which eliminates the economic value of the plants. Numeral researches have been done to address the phenomenon but the molecular mechanisms of sago palm respond toward the responsible stresses are still lacking. Therefore, in this study we collected samples from Trunking (Normal) and Non-Trunking sago palm leaf samples which planted on peat soil for total RNA extraction followed by next generation sequencing using BGISEQ-500 platform. The raw reads were cleaned and de novo assembled using TRINITY software package. Total of 40.11 Gb bases were sequenced from the sago palm leaf samples and after assembled producing 102,447 unigenes, with N50 score 1,809 bp and GC ratio of 44.34%. Unigenes by aligning with 7 (NR, NT, GO, KOG, KEGG, SwissProt & InterPro) functional databases and 65,523 (63.96%) unigenes were annotated. Functional annotation results in the detection of 46,335 Coding DNA sequences by Transdecoder. 30,039 Simple-sequence repeats distributed on 21,676 Unigenes were detected using Primer3 software, and 2,355 Transcription Factor coding Unigenes were predicted using getorf and hmmseach software. A total of 492 up-regulated and 444 down-regulated at least two-fold differential expressed gene were detected using DESeq2 algorithm with 95% confidence.
Project description:Gray leaf spot (GLS) disease of maize is caused by the fungus Cercospora zeina in African countries, such as South Africa. The plant material was from maize inbred line B73-QTL, which was introgressed with a QTL region for resistance to GLS from the maize inbred line CML444 (Berger et al (2014) BMC Genetics 15 60 www.biomedcentral.com/1471-2156/15/60 ). This QTL was named 10G2_GLS and 10H_GLS from two field trials in KwaZulu-Natal province, South Africa in that study. B73-QTL plants were planted in the field, and subjected to natural infection with C. zeina. This was the same field trial as B73 plants that were sampled for RNAseq and the data reported in Swart et al (2017) Mol Plant Microbe Interact 30 710-724 (2017)(GSE94442). Samples were collected from lower leaves with moderate GLS lesions and younger upper leaves of the same B73-QTL plants with very few immature GLS lesions. The first aim of the experiment was to compare the maize transcriptomes during C.zeina challenge between B73 (from GSE94442 data) and B73-QTL plants (this study). The second aim was to identify novel transcripts expressed from the QTL region, which may underlie the quantitative disease resistance to GLS. The third aim was to identify C. zeina genes expressed in planta during infection.
2020-02-14 | GSE137198 | GEO
Project description:diazotrophs community during forest succession in lowland subtropical forests
Project description:The rhizosphere is a small region surrounding plant roots that is enriched in biochemicals from root exudates and populated with fungi, nematode, and bacteria. Interaction of rhizosphere organisms with plants is mainly promoted by exudates from the roots. Root exudates contain biochemicals that come from primary and secondary metabolisms of plants. These biochemicals attract microbes, which influence plant nutrition. The rhizosphere bacteria (microbiome) are vital to plant nutrient uptake and influence biotic and abiotic stress and pathogenesis. Pseudomonas is a genus of gammaproteobacteria known for its ubiquitous presence in natural habitats and its striking ecological, metabolic, and biochemical diversity. Within the genus, members of the Pseudomonas fluorescens group are common inhabitants of soil and plant surfaces, and certain strains function in the biological control of plant disease, protecting plants from infection by soilborne and aerial plant pathogens. The soil bacterium Pseudomonas protegens Pf-5 (also known as Pseudomonas fluorescens Pf-5) is a well-characterized biological strain, which is distinguished by its prolific production of the secondary metabolite, pyoverdine. Knowledge of the distribution of P. fluorescens secretory activity around plant roots is very important for understanding the interaction between P. fluorescens and plants and can be achieved by real time tracking of pyoverdine. To achieve the capability of real-time tracking in soil, we have used a structure-switching SELEX strategy to select high affinity ssDNA aptamers with specificity for pyoverdine over other siderophores. Two DNA aptamers were isolated, and their features compared. The aptamers were applied to a nanoporous aluminum oxide biosensor and demonstrated to successfully detect PYO-Pf5. This sensor provides a future opportunity to track the locations around plant roots of P. protegens and to monitor PYO-Pf5 production and movement through the soil.