Project description:Intensive application of inorganic nitrogen underlies marked increase in crop production yet imposes detrimental impact on ecosystems, hence it is crucial for future sustainable agriculture to improve nitrogen-use efficiency (NUE). Here we report the genetic basis of NUE associated with the local soil adaptation in rice. With a diverse rice germplasm panel collected from different ecogeographic regions, we performed genome-wide association study on tillering response to nitrogen (TRN), the most correlated trait with NUE of rice, and identified OsTCP19 as a modulator of TRN via transcriptionally responding to nitrogen and targeting to Dwarf and Low-Tillering (DLT), a tiller-promoting gene. A 29-bp InDel in OsTCP19 promoter confers differential transcription response to nitrogen and TRN variation among rice varieties. The high-TRN allele of OsTCP19 (OsTCP19-H) is prevalent in wild rice population, but largely lost in modern cultivars correlating with increased local soil nitrogen content, suggesting that it might have contributed to geographic adaptation in rice. Introgression of OsTCP19-H into modern rice cultivars boosts grain yield and NUE under low or moderate nitrogen levels, demonstrating its enormous potential for rice breeding and environment amelioration through reducing nitrogen application.
Project description:In this study we show the transcriptional analysis after shifting the Ustilago maydis from media with ammonium as a nitrogen source to media lacking ammonium. From these, 49 genes were up-regulated and 41 were down-regulated. The functional description and gene ontology terms associated to the diferentially expressed genes revealed that various key pathways were represented, including, secondary metabolism, the metabolism of nitrogen, amino acid, fatty acid and amino sugar, among others, suggesting that the interplay of U. maydis with its N2 fixing bacterial endosymbiont is a flexible process that may be active during the adaptation to the fungus to the different nitrogen sources, and possibly during its pathogenic style of life.
Project description:Apis laboriosa, the Himalayan giant honey bee, is a species of honey bees (genus Apis), which is highly adapted to highland habitats and mainly occurs in mountainous regions, particularly the Himalayas. Up to data, the genetic basis of its high-elevation adaptation remains a mystery. In the present study, we generated transcriptomes for A. laboriosa and its closely related species A. dorsata, we then characterized the transcriptomes and did comparative and evolutionary analysis between them to understand the genetic basis of high-altitude adaptation in A. laboriosa. We identified 1,605 genes that are absent in A. dorsata but present in A. laboriosa. Those A. laboriosa-specific genes were involved in DNA damage repair, low temperature tolerance and oxidative stress response. In addition, for genes shared by the two species, genes related to anoxia tolerance, freeze tolerance and UV irradiation were positively selected in A. laboriosa. Taken together, our results suggest that both the increased copy number and the accelerated protein sequence evolution of genes related to high-elevation adaptation made a difference between A. laboriosa and A. dorsata, which should contribute to the adaptation of A. laboriosa to challenging environments in Himalayas.
Project description:Analysis of 96-hours-old-rice seedlings with promoted-growth induced by implantation with low-energy nitrogen ion beam. Ion-beam implantation can induce changes in 351 up-regulated transcripts and 470 down-regulated transcripts, including signaling proteins, kinases, plant hormones, transposable elements, transcription factors, non-coding protein RNAs, secondary metabolites, resistance proteins, peroxidase, chromatin modification and even miRNAs. Results provide insight into the molecular basis of biological effects of plants that implanted by ion beam.
Project description:Transcriptomic analyses using high-throughput methods have revealed abundant antisense transcription in bacteria. Most frequently, antisense transcription is due to the overlap of mRNAs with long 5’ regions or 3’ ends that extend beyond the coding sequence. In addition, antisense RNAs that do not contain any coding sequence are also observed. Nostoc sp. PCC 7120 is a filamentous cyanobacterium that, under nitrogen limitation, behaves as a multicellular organism with division of labor among two different cell types that depend on each other, the vegetative CO2-fixing cells and the nitrogen-fixing heterocysts. Differentiation of heterocysts depends on the global nitrogen regulator NtcA and requires the specific regulator HetR. To identify antisense RNAs potentially involved in heterocyst differentiation we performed an RNA-Seq analysis of cells subjected to nitrogen limitation (either at 9 or 24 hours after nitrogen removal) and analyzed the results in combination with a genome-wide set of nitrogen-regulated transcriptional start sites and a prediction of transcriptional terminators. Our analysis resulted in the definition of a transcriptional map including more than 4,000 transcripts, 65% of them in antisense orientation to other transcripts. In addition to overlapping mRNAs we identified nitrogen-regulated non-coding antisense RNAs transcribed from NtcA-dependent or HetR-dependent promoters.
Project description:Understanding gene expression re-programming in response to limiting nitrogen (N) conditions is crucial for ongoing progress towards the development of crop varieties with improved nitrogen use efficiency. We analyzed expression data obtained from leaves and roots of rice plants adapted to sufficient and limiting nitrate as well as after shifting them to low (reduction) and sufficient (induction) nitrate conditions.
Project description:The goal of the research is to identify the physiological pathways that influence survival, growth, and competitive ability of the species of yeast that colonize floral nectar. Initially sterile, floral nectar is colonized by multiple species of microbes via insects and birds that visit the flowers for nectar. Once colonized, the microbes face two major challenges of the nectar environment: high osmotic pressure, caused by excessive carbon supply, and strong resource competition, caused by low nitrogen availability. We propose to study the genetic basis of the unique ecological strategies that allow nectar yeasts to cope with these challenges, and to determine the effects that these genes may have on microbe microbe interactions in nectar and the chemical properties of nectar that affect pollinator preference.
The work (proposal:https://doi.org/10.46936/10.25585/60001130) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.