Spirodela polyrhiza isolate:sp9512 Genome sequencing

Over 15 families of aquatic plants are known to use a similar strategy of developmental switching upon environmental stress to produce dormant propagules called turions. We carried out RNA-seq analysis of mature turions from the Greater Duckweed Spirodela polyrhiza and compared its transcriptome to that of fronds, the actively growing leaf-like tissue that turions are derived from. Our study revealed about 3,000 high-confidence transcripts that displayed more than a 4-fold difference between these two states. Gene ontology analysis of these transcripts informed on the pathways related to dormancy, stress tolerance and metabolism that are mobilized to reprogram frond meristems for turion differentiation. Furthermore, we identified genes involved in rewiring the biosynthetic pathways to drive increased starch and lipid accumulation, as well as to prepare for their metabolism upon germination. Lastly, comparison of genome-wide cytosine methylation levels revealed evidence for epigenetic control in the transition between frond and turion tissues.