Project description:The Solanaceae species Nicotiana tabacum, an economically important crop plant cultivated worldwide, is an allotetraploid species that appeared about 200,000 years ago as the result of the hybridization of diploid ancestors of Nicotiana sylvestris and Nicotiana tomentosiformis. The previously published genome assemblies for these three species relied primarily on short-reads, and the obtained pseudochromosomes only partially covered the genomes. In this study, we generated annotated de novo chromosome-level genomes of N. tabacum, N. sylvestris, and N. tomentosiformis, which contain 3.99 Gb, 2.32 Gb, and 1.74 Gb, respectively of sequence data, with 97.6%, 99.5%, and 95.9% aligned in chromosomes, and represent 99.2%, 98.3%, and 98.5% of the near-universal single-copy orthologs Solanaceae genes. The completion levels of these chromosome-level genomes for N. tabacum, N. sylvestris, and N. tomentosiformis are comparable to other reference Solanaceae genomes, enabling more efficient synteny-based cross-species research.
Project description:Pollen development is one of the most heat-sensitive developmental stages in a wide range of crops. Our longer-term goal is to understand the mechanism how starch metabolism in maturing pollen grains of the Solanaceae family contributes to maintaining higher pollen quality under heat-stress conditions. The specific aim of the suggested proposal is to characterize N. sylvestris WT and mutant (starch-deficient) transcriptomes during microgametogenesis under ambient and heat-stress conditions. Expression profiles of maturing microspores derived from flower buds at developmental stage of 4 to 2 days before flower opening will be obtained. Pollen was derived from WT and mutant plants exposed to either ambient or heat-stress conditions (exposing the plants to 45oC for 2.5 hours). Keywords: Loop design