RT Journal Article
SR Electronic
T1 Chromosome-Scale Genome Assembly Provides Insights into Speciation of Allotetraploid and Massive Biomass Accumulation of Elephant Grass (<em>Pennisetum purpureum</em> Schum.)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.02.28.970749
DO 10.1101/2020.02.28.970749
A1 Shengkui Zhang
A1 Zhiqiang Xia
A1 Wenqing Zhang
A1 Can Li
A1 Xiaohan Wang
A1 Xianqin Lu
A1 Xianyan Zhao
A1 Haizhen Ma
A1 Xincheng Zhou
A1 Weixiong Zhang
A1 Tingting Zhu
A1 Pandao Liu
A1 Guodao Liu
A1 Hubiao Yang
A1 Jacobo Arango
A1 Michael Peters
A1 Wenquan Wang
A1 Tao Xia
YR 2020
UL http://biorxiv.org/content/early/2020/03/02/2020.02.28.970749.abstract
AB Elephant grass (Pennisetum purpureum Schum., A’A’BB, 2n=4x=28), which is characterized as robust growth and high biomass, and widely distributed in tropical and subtropical areas globally, is an important forage, biofuels and industrial plant. We sequenced its allopolyploid genome and assembled 2.07 Gb (96.88%) into A’ and B sub-genomes of 14 chromosomes with scaffold N50 of 8.47 Mb. A total of 38,453 and 36,981 genes were annotated in A’ and B sub-genomes, respectively. A phylogenetic analysis with species in Pennisetum identified that the speciation of the allotetraploid occurred approximately 15 MYA after the divergence between S.italica and P. glaucum. Double whole-genome duplication (WGD) and polyploidization events resulted in large scale gene expansion, especially in the key steps of growth and biomass accumulation. Integrated transcriptome profiling revealed the functional differentiation between sub-genomes; A’ sub-genome contributed more to plant growth, development and photosynthesis whereas B sub-genome primarily offered functions of effective transportation and resistance to stimulation. The results uncovered enhanced cellulose and lignin biosynthesis pathways with 645 and 666 genes expanded in A’ and B sub-genomes, respectively. Our findings provided deep insights into the speciation and genetic basis of fast growth and high biomass accumulation in the species. The genetic, genomic, and transcriptomic resources generated in this study will pave the way for further domestication and selection of these economical species and making them more adaptive to industrial utilization.