Differential expression of genes involved in the biosynthesis and perception of ethylene during ripening of passion fruit (Passiflora edulis Sims).
An increase in the enzyme activity of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase induces the evolution of ethylene during the ripening of passion fruit. A much higher level of ethylene is produced in arils than in seeds or peels during ripening. The pattern of expression of two ACC synthase genes (PE-ACS1 and PE-ACS2), one ACC oxidase gene (PE-ACO1), and two ethylene receptor genes (PE-ETR1 and PE-ERS1) revealed that the expression of these genes is differentially regulated. Expression of PE-ACS1 and PE-ACO1 was enhanced during ripening and after ethylene treatment. However, prominent expression of PE-ACS1 was delayed compared to that of PE-ACO1. Much larger quantities of PE-ACS1 mRNA and PE-ACO1 mRNA were seen in arils than in seeds; this corresponds well with an increase in the amount of ethylene produced by the plant tissue itself. The level of PE-ACS2 mRNA was detectable in arils of the preclimacteric fruit, although it decreased during ripening. These results suggest that expression of PE-ACS1 and PE-ACO1 is required to increase the activity of ethylene biosynthetic enzymes during ripening. The level of expression of PE-ETR1 and PE-ERS1 did not significantly change over the course of ripening; however, the mRNA levels of PE-ETR1 and PE-ERS1 were much higher in arils than in seeds.
Mita
S
S
Department of Biological Sciences, Faculty of Agriculture, Shizuoka University, Japan.
Kawamura
S
S
Yamawaki
K
K
Nakamura
K
K
Hyodo
H
H
D000594:Amino Acid Oxidoreductases / Q000096:biosynthesis / Q000235:genetics*; D000595:Amino Acid Sequence; D005030:Ethylenes / Q000494:pharmacology*; D005638:Fruit / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D017343:Genes, Plant; D008190:Lyases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009636:Norbornanes / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics* / Q000502:physiology
D005030:Ethylenes; D009636:Norbornanes; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C083750:ethylene receptors, plant; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase; C048294:2,5-norbornadiene