Chromosome-Scale Genome Assembly Provides Insights into Speciation of Allotetraploid and Massive Biomass Accumulation of Elephant Grass (Pennisetum purpureum Schum.)

摘要: Abstract Elephant grass (Pennisetum purpureum Schum., A’A’BB, 2n=4x=28), which is characterized as robust growth and high biomass, widely distributed in tropical subtropical areas globally, an important forage, biofuels industrial plant. We sequenced its allopolyploid genome assembled 2.07 Gb (96.88%) into A’ B sub-genomes of 14 chromosomes with scaffold N50 8.47 Mb. A total 38,453 36,981 genes were annotated sub-genomes, respectively. phylogenetic analysis species Pennisetum identified that the speciation allotetraploid occurred approximately 15 MYA after divergence between S.italica P. glaucum. Double whole-genome duplication (WGD) polyploidization events resulted large scale gene expansion, especially key steps biomass accumulation. Integrated transcriptome profiling revealed functional differentiation sub-genomes; sub-genome contributed more to plant growth, development photosynthesis whereas primarily offered functions effective transportation resistance stimulation. The results uncovered enhanced cellulose lignin biosynthesis pathways 645 666 expanded Our findings provided deep insights genetic basis fast accumulation species. genetic, genomic, transcriptomic resources generated this study will pave way for further domestication selection these economical making them adaptive utilization.