Bananas(Musa spp.)are monocotyledonous plants with high genetic diversity in the Musaceae family that are cultivated mainly in tropical and subtropical countries.The fruits are a popular food,and the plants themselves...Bananas(Musa spp.)are monocotyledonous plants with high genetic diversity in the Musaceae family that are cultivated mainly in tropical and subtropical countries.The fruits are a popular food,and the plants themselves have diverse uses.Four genetic groups(genomes)are thought to have contributed to current banana cultivars:Musa acuminata(A genome),Musa balbisiana(B genome),Musa schizocarpa(S genome),and species of the Australimusa section(T genome).However,the T genome has not been effectively explored.Here,we present the high-quality TT genomes of two representative accessions,Abaca(Musa textilis),with high-quality naturalfiber,and Utafun(Musa troglodytarum,Fe’i group),with abundant b-carotene.Both the Abaca and Utafun assemblies comprise 10 pseudochromosomes,and their total genome sizes are 613 Mb and 619 Mb,respectively.Comparative genome analysis revealed that the larger size of the T genome is likely attributable to rapid expansion and slow removal of trans-posons.Compared with those of Musa AA or BB accessions or sisal(Agava sisalana),Abacafibers exhibit superior mechanical properties,mainly because of their thicker cell walls with a higher content of cellulose,lignin,and hemicellulose.Expression of MusaCesA cellulose synthesis genes peaks earlier in Abaca than in AA or BB accessions during plant development,potentially leading to earlier cellulose accumulation during secondary cell wall formation.The Abaca-specific expressed gene MusaMYB26,which is directly regulated by MusaMYB61,may be an important regulator that promotes precocious expression of secondary cell wall MusaCesAs.Furthermore,MusaWRKY2 and MusaNAC68,which appear to be involved in regulating expression of MusaLAC and MusaCAD,may at least partially explain the high accumulation of lignin in Abaca.This work contributes to a better understanding of banana domestica-tion and the diverse genetic resources in the Musaceae family,thus providing resources for Musa genetic improvement.展开更多
基金funded by the National Key R&D Program of China (2019YFD1000203 and 2019YFD1000900)the National Natural Science Foundation of China (32270712)+3 种基金the earmarked fund for CARS (CARS-31-01)GDAAS (202102TD,and R2020PY-JX002)funds for the strategy of rural vitalization of Guangdong province,a Laboratory of Lingnan Modern Agriculture Project (NT2021004)a Maoming Branch grant (2021TDQD003).
文摘Bananas(Musa spp.)are monocotyledonous plants with high genetic diversity in the Musaceae family that are cultivated mainly in tropical and subtropical countries.The fruits are a popular food,and the plants themselves have diverse uses.Four genetic groups(genomes)are thought to have contributed to current banana cultivars:Musa acuminata(A genome),Musa balbisiana(B genome),Musa schizocarpa(S genome),and species of the Australimusa section(T genome).However,the T genome has not been effectively explored.Here,we present the high-quality TT genomes of two representative accessions,Abaca(Musa textilis),with high-quality naturalfiber,and Utafun(Musa troglodytarum,Fe’i group),with abundant b-carotene.Both the Abaca and Utafun assemblies comprise 10 pseudochromosomes,and their total genome sizes are 613 Mb and 619 Mb,respectively.Comparative genome analysis revealed that the larger size of the T genome is likely attributable to rapid expansion and slow removal of trans-posons.Compared with those of Musa AA or BB accessions or sisal(Agava sisalana),Abacafibers exhibit superior mechanical properties,mainly because of their thicker cell walls with a higher content of cellulose,lignin,and hemicellulose.Expression of MusaCesA cellulose synthesis genes peaks earlier in Abaca than in AA or BB accessions during plant development,potentially leading to earlier cellulose accumulation during secondary cell wall formation.The Abaca-specific expressed gene MusaMYB26,which is directly regulated by MusaMYB61,may be an important regulator that promotes precocious expression of secondary cell wall MusaCesAs.Furthermore,MusaWRKY2 and MusaNAC68,which appear to be involved in regulating expression of MusaLAC and MusaCAD,may at least partially explain the high accumulation of lignin in Abaca.This work contributes to a better understanding of banana domestica-tion and the diverse genetic resources in the Musaceae family,thus providing resources for Musa genetic improvement.
