Metabolic Profiling in Banana Pseudo-Stem Reveals a Diverse Set of Bioactive Compounds with Potential Nutritional and Industrial Applications

Banana(Musa spp.)is an ancient and popular fruit plant with highly nutritious fruit.The pseudo-stem of banana represents on average 75%of the total dry mass but its valorization as a nutritional and industrial by-product is limited.Recent advances in metabolomics have paved the way to understand and evaluate the presence of diverse sets of metabolites in different plant parts.This study aimed at exploring the diversity of primary and secondary metabolites in the banana pseudo-stem.Hereby,we identified and quantified 373 metabolites from a diverse range of classes including,alkaloids,flavonoids,lipids,phenolic acids,amino acids and its derivatives,nucleotide and its derivatives,organic acids,lignans and coumarins,tannins,and terpene using the widely-targeted metabolomics approach.Banana pseudo-stem is enriched in metabolites for utilization in the food industry(L-lysine and L-tryptophan,L-glutamic acid,Phenylalanine,Palmitoleic acid,α-Linolenic acid,and Lauric acid,and Adenine)and pharmaceutical industry(Guanosine and Cimidahurinine,Bergapten,Coumarins,Procyanidin A2,Procyanidin B1,Procyanidin B3,Procyanidin B2,and Procyanidin B4,Asiatic acid).The metabolome of banana pseudo-stem with integration across multiomics data may provide the opportunity to exploit the rich metabolome of banana pseudo-stem for industrial and nutritional applications.

Two haplotype-resolved genome assemblies for AAB allotriploid bananas provide insights into banana subgenome asymmetric evolution and Fusarium wilt control

Bananas(Musa spp.)are one of the world’s most important fruit crops and play a vital role in food security for many developing countries.Most banana cultivars are triploids derived from inter-and intraspecific hybrid-izations between the wild diploid ancestor species Musa acuminate(AA)and M.balbisiana(BB).We report two haplotype-resolved genome assemblies of the representative AAB-cultivated types,Plantain and Silk,and precisely characterize ancestral contributions by examining ancestry mosaics across the genome.Widespread asymmetric evolution is observed in their subgenomes,which can be linked to frequent homol-ogous exchange events.We reveal the genetic makeup of triploid banana cultivars and verify that subge-nome B is a rich source of disease resistance genes.Only 58.5%and 59.4%of Plantain and Silk genes,respectively,are present in all three haplotypes,with>50%of genes being differentially expressed alleles in different subgenomes.We observed that the number of upregulated genes in Plantain is significantly higher than that in Silk at one-week post-inoculation with Fusarium wilt tropical race 4(Foc TR4),which con-firms that Plantain can initiate defense responses faster than Silk.Additionally,we compared genomic and transcriptomic differences among the genes related to carotenoid synthesis and starch metabolism between Plantain and Silk.Our study provides resources for better understanding the genomic architecture of culti-vated bananas and has important implications for Musa genetics and breeding.

High-quality genome assemblies for two Australimusa bananas(Musa spp.)and insights into regulatory mechanisms of superior fiber properties

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.

Efficient and transgene‑free genome editing in banana using a REG‑2 promoter-driven gene‑deletion system

The Streptococcus-derived CRISPR/Cas9 system can introduce precise and predictable modifications into the plant genome to obtain the desired traits.As one of the most advanced tools for editing crop genomes,the CRISPR/Cas9 system has been expanding rapidly and has been widely applied to determine gene function and improve agronomic traits in horticultural crops such as fruits and vegetables(Ma et al.2023).