Characterization of transcriptional profiles of MA-ACS1 and MA-ACO1 genes in response to ethylene, auxin, wounding, cold and different photoperiods during ripening in banana fruit.
The ripening-specific genes MA-ACS1 (Musa acuminata ACC synthase1) and MA-ACO1 (M. acuminata ACC oxidase 1) are regulated in response to a wide variety of factors. Here, we have studied the differential transcript accumulation pattern and protein levels of MA-ACS1 and MA-ACO1 genes in response to ethylene, auxin, wounding and low temperature in preclimacteric banana fruit. We have shown that exogenous application of ethylene and auxin induced the expression of MA-ACS1, while MA-ACO1 showed marginal expression following ethylene treatment in preclimacteric stage. Auxin did not induce MA-ACO1 expression. Thus, auxin-treated banana fruits showed lower ethylene production rate as compared to ethylene-treated fruits. Conversely, wounding and cold treatment down-regulated the expression of both the genes and thus inhibited ethylene production. Furthermore, we have detected a GCC-box putative ethylene-responsive element (ERE)- and an auxin-responsive element (ARE)-specific DNA-binding activity in the banana pulp and studied the ethylene and auxin responsive characteristics of the GCC-box and ARE (TGTCTC) containing synthetic promoter fragments. In addition, we have detected an enhanced ethylene production rate and expression level of MA-ACS1 and MA-ACO1 genes along with a strong GCC-box-specific DNA-binding activity following exposure to constant dark period for 8d at the preclimacteric stage. Together, our study provides interesting information about the regulation of expression of MA-ACS1 and MA-ACO1 genes in response to various factors during ripening in banana fruit, which may have physiological relevance concerning ethylene biosynthesis during post-harvest conditions.
Department of Botany, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata-700 009, West Bengal, India.
Swarup Roy
SR
Choudhury
Sujit
S
Roy
Dibyendu N
DN
Sengupta
D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000598:Amino Acids, Cyclic / Q000378:metabolism; D003080:Cold Temperature; D018744:DNA, Plant / Q000378:metabolism; D003624:Darkness; D005030:Ethylenes / Q000096:biosynthesis / Q000494:pharmacology*; D005638:Fruit / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008190:Lyases / Q000235:genetics / Q000378:metabolism; D028521:Musa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D017440:Photoperiod; D011485:Protein Binding / Q000187:drug effects; D020218:Response Elements / Q000235:genetics; D017384:Sequence Deletion; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation / Q000187:drug effects
D000598:Amino Acids, Cyclic; D018744:DNA, Plant; D005030:Ethylenes; D007210:Indoleacetic Acids; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase