香蕉Fibrillin家族全基因组鉴定及其在中热1号中的表达分析OA

Fibrillin(FBN)is a type of plastid lipid-associated protein widely found in plants.As structural proteins for plastoglobuli formation,FBNs are indispensable for massive carotenoid accumulation.To explore the role of the MaFBN gene family in banana carotenoid accumulation,this study analyzed their physicochemical properties,phylogenetic evolution,gene duplication events,and promoter cis-acting elements.The expression patterns of MaFBN members were also analyzed in dif-ferent tissues and fruits at various maturity stages of'Zhongre 1'banana.A total of 13 MaFBN members were identified from the banana genome,which were unevenly distributed on nine chromosomes.All encoded proteins contained the conserved PAP domain.Physicochemical analysis showed that the amino acid length ranged from 217(MaFBN10)to 667(MaFBN6),the molecular weights ranged from 23.69-74.61 kDa,the theoretical isoelectric point ranged from 5.15-9.65,the instability index ranged from 28.32-62.75,and all proteins were hydrophilic.Subcellular localization prediction indicated that all members localized to chloroplasts.MaFBN2 was also detected in the nucleus,while MaFBN6 was distributed in three sites:the chloro-plast,cytoplasm,and nucleus.Phylogenetic analysis divided the MaFBN family into 11 subgroups.Promoter sequences har-bored cis-elements related to light response,drought induction,low temperature response,hormone response,and defense stress.MaFBN8 showed strong flower-specific expression,with significantly higher transcript abundance in flowers than in roots,stems,leaves,and fruits.In fruits of different maturities,MaFBN12 expression was relatively high at the harvest stage,rose sharply to a peak at the initiation stage of ethylene biosynthesis,and declined slightly but remained at a high level at the vigorous ethylene synthesis stage.Its expression trend was consistent with fruit carotenoid content variation.It is inferred that MaFBN12 acts as a key gene regulating banana fruit color formation and carotenoid accumulation.