Project description:Gluconacetobacter diazotrophicus PAl 5 is of agricultural significance due to its ability to provide fixed nitrogen to plants. Consequently, its genome sequence has been eagerly anticipated to enhance understanding of endophytic nitrogen fixation. Two groups have sequenced the PAl 5 genome from the same source (ATCC 49037), though the resulting sequences contain a surprisingly high number of differences. Therefore, an optical map of PAl 5 was constructed in order to determine which genome assembly more closely resembles the chromosomal DNA by aligning each sequence against a physical map of the genome. While one sequence aligned very well, over 98% of the second sequence contained numerous rearrangements. The many differences observed between these two genome sequences could be owing to either assembly errors or rapid evolutionary divergence. The extent of the differences derived from sequence assembly errors could be assessed if the raw sequencing reads were provided by both genome centers at the time of genome sequence submission. Hence, a new genome sequence standard is proposed whereby the investigator supplies the raw reads along with the closed sequence so that the community can make more accurate judgments on whether differences observed in a single stain may be of biological origin or are simply caused by differences in genome assembly procedures.
Project description:We leverage a model nitrogen-fixing plant symbiont and integrate genomics, phenotypes, and gene expression data to associate sets of gene clusters, which are frequently gained and lost in natural populations, with plant growth. We reveal novel structural and modular genetic processes with implications for the function and inheritance of symbiosis function in plant-microbe interactions.
Project description:We characterized the polyethylene glycol (PEG)-responding desiccome from the most geographically widespread Gram-positive nitrogen-fixing plant symbiont, i.e. Frankia alni, by next-generation proteomics.