EIN3-like gene expression during fruit ripening of Cavendish banana (Musa acuminata cv. Grande naine).
Ethylene signal transduction initiates with ethylene binding at receptor proteins and terminates in a transcription cascade involving the EIN3/EIL transcription factors. Here, we have isolated four cDNAs homologs of the Arabidopsis EIN3/EIN3-like gene, MA-EILs (Musa acuminata ethylene insensitive 3-like) from banana fruit. Sequence comparison with other banana EIL gene already registered in the database led us to conclude that, at this day, at least five different genes namely MA-EIL1, MA-EIL2/AB266318, MA-EIL3/AB266319, MA-EIL4/AB266320 and AB266321 exist in banana. Phylogenetic analyses included all banana EIL genes within a same cluster consisting of rice OsEILs, a monocotyledonous plant as banana. However, MA-EIL1, MA-EIL2/AB266318, MA-EIL4/AB266320 and AB266321 on one side, and MA-EIL3/AB266319 on the other side, belong to two distant subclusters. MA-EIL mRNAs were detected in all examined banana tissues but at lower level in peel than in pulp. According to tissues, MA-EIL genes were differentially regulated by ripening and ethylene in mature green fruit and wounding in old and young leaves. MA-EIL2/AB266318 was the unique ripening- and ethylene-induced gene; MA-EIL1, MA-EIL4/Ab266320 and AB266321 genes were downregulated, while MA-EIL3/AB266319 presented an unusual pattern of expression. Interestingly, a marked change was observed mainly in MA-EIL1 and MA-EIL3/Ab266319 mRNA accumulation concomitantly with changes in ethylene responsiveness of fruit. Upon wounding, the main effect was observed in MA-EIL4/AB266320 and AB266321 mRNA levels, which presented a markedly increase in both young and old leaves, respectively. Data presented in this study suggest the importance of a transcriptionally step control in the regulation of EIL genes during banana fruit ripening.
Mbéguié-A-Mbéguié
Didier
D
CIRAD, UMR 94 QUALITROP, Capesterre-Belle-Eau, Guadeloupe, F-97130, France. didier.mbeguie-a-mbeguie@cirad.fr
Hubert
Olivier
O
Fils-Lycaon
Bernard
B
Chillet
Marc
M
Baurens
Franc-Christophe
FC
D000114:Acetylene / Q000494:pharmacology; D029681:Arabidopsis Proteins / Q000235:genetics*; D015139:Blotting, Southern; D003521:Cyclopropanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000302:isolation & purification; D004268:DNA-Binding Proteins; D005638:Fruit / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008969:Molecular Sequence Data; D028521:Musa / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D009687:Nuclear Proteins / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics*
D029681:Arabidopsis Proteins; D003521:Cyclopropanes; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C106987:EIN3 protein, Arabidopsis; D009687:Nuclear Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C412563:1-methylcyclopropene; D000114:Acetylene