Project description:Purpose: To elucidate the potential molecular mechanisms that are involved in drought tolerance of Haloxylon ammodendron. Method: Pathways and candidate genes drought-resistant genes were identified in shoots and roost of Haloxylon ammodendron under sorbitol treatment for 6 and 24h using RNA-seq and Digital Gene Expression. Results: 3,353 differently expressed genes in shoots and 4,564 in roots were successfully indentified. Conclusion: A detailed investigation of the pathways and candidate genes identified in this study promote the research on the molecular mechanisms of drought resistance in the xerophytic species, and lay a solid foundation for developing stress-tolerant forage and crop species by using excellent genes relevant to drought tolerance in Haloxylon. ammodendron.
Project description:Chromatin immunoprecipitation analysis of CENH3 in the Arabidopsis thaliana accessions Col-0, Ler-0, Cvi-0 and Tanz-1 was performed in order to align reads to PacBio HiFi genome assemblies which contain complete centromere repeat arrays.
Project description:Dikaryotic rust fungi maintain two distinct haploid nuclei for most of their life cycle, making their large, repeat-rich genomes difficult to assemble and phase. Here we present haplotype-phased, near chromosome-scale genome assemblies for the poplar rust pathogens Melampsora larici-populina 98AG31 and Melampsora allii-populina 12AY07, generated using PacBio HiFi sequencing and Hi-C-guided scaffolding. For each species, we resolve 18 chromosomes per haplotype, providing the first chromosome-level representations of poplar rust fungal species. M. larici-populina diploid assembly spans ~203 Mb, while M. allii-populina reaches ~416 Mb, with high completeness and strong collinearity between haplotypes.
Project description:Drought is an inevitable stress almost all terrestrial plants face in their life cycles. Desert dwelling plants show extreme adaptations to drought but their genomes are largely unexplored compared to drought sensitive model plants generally studied to understand plant drought tolerance. Haloxylon ammodendron is a pioneer species extremely tolerant to drought and capable of colonizing desert sand dunes. Seedling establishment is the most critical development stage in the survival of H. ammodendron. H. ammodendron seedlings are able to withstand high light, and low temperature stresses characteristic of temperate desert environments in addition to drought. We have investigated the genome-wide transcript responses under induced drought stress during early seedling establishment to identify prevailing basal and induced gene clusters that likely contribute to survival and stress adapted growth in H. ammodendron. We find staggering support for drought response transcript accumulation together with other transcripts that may transform the cellular expression space into a preadapted state for salt, light, osmotic, and temperature stress tolerance. While transcript accumulation is excessive for genes associated with abiotic stress tolerance under an induced drought treatment, H. ammodendron seems to enhance biotic stress tolerance simultaneously by down-regulation of several genes that would be found at an up-regulated state during pathogen entry in susceptible plants. We detected enriched basal level transcript allocation that suggests preadaptation to abiotic stresses as well as pathogen defense in H. ammodendron when compared to other Amaranthaceae family transcriptomes under stress neutral conditions. Amaranthaceae is one of the most enriched plant families for extremophytes. We found transcripts that are generally maintained at low levels and some induced only under abiotic stress in Arabidopsis thaliana to be highly expressed under basal conditions in the Amaranthaceae transcriptomes including H. ammodendron. These could be novel candidates to expand or initiate discovery of new stress adaptive gene networks and mechanisms naturally selected in extremophytes that allow survival under environmental stresses.