Molecular characterization and expression studies during melon fruit development and ripening of L-galactono-1,4-lactone dehydrogenase

TY - JOUR

T1 - Molecular characterization and expression studies during melon fruit development and ripening of L-galactono-1,4-lactone dehydrogenase

AU - Pateraki, Irene

AU - Sanmartin, Maite

AU - Kalamaki, Mary S.

AU - Gerasopoulos, Dimitrios

AU - Kanellis, Angelos K.

AU - Pateraki, Eirini

PY - 2004/8/1

Y1 - 2004/8/1

N2 - The last step of ascorbic acid (AA) biosynthesis is catalysed by the enzyme L-galactono-1,4-lactone dehydrogenase (GalLDH, EC 1.3.2.3), located on the inner mitochondrial membrane. The enzyme converts L-galactono-1,4-lactone to ascorbic acid (AA). In this work, the cloning and characterization of a GalLDH full-length cDNA from melon (Cucumis melo L.) are described. Melon genomic DNA Southern analysis indicated that CmGalLDH was encoded by a single gene. CmGalLDH mRNA accumulation was detected in all tissues studied, but differentially expressed during fruit development and seed germination. It is hypothesized that induction of CmGalLDH gene expression in ripening melon fruit contributes to parallel increases in the AA content and so playing a role in the oxidative ripening process. Higher CmGalLDH message abundance in light-grown seedlings compared with those raised in the dark suggests that CmGalLDH expression is regulated by light. Finally, various stresses and growth regulators resulted in no significant change in steady state levels of CmGalLDH mRNA in 20-d-old melon seedlings. To the authors' knowledge, this is the first report of GalLDH transcript induction in seed germination and differential gene expression during fruit ripening.

AB - The last step of ascorbic acid (AA) biosynthesis is catalysed by the enzyme L-galactono-1,4-lactone dehydrogenase (GalLDH, EC 1.3.2.3), located on the inner mitochondrial membrane. The enzyme converts L-galactono-1,4-lactone to ascorbic acid (AA). In this work, the cloning and characterization of a GalLDH full-length cDNA from melon (Cucumis melo L.) are described. Melon genomic DNA Southern analysis indicated that CmGalLDH was encoded by a single gene. CmGalLDH mRNA accumulation was detected in all tissues studied, but differentially expressed during fruit development and seed germination. It is hypothesized that induction of CmGalLDH gene expression in ripening melon fruit contributes to parallel increases in the AA content and so playing a role in the oxidative ripening process. Higher CmGalLDH message abundance in light-grown seedlings compared with those raised in the dark suggests that CmGalLDH expression is regulated by light. Finally, various stresses and growth regulators resulted in no significant change in steady state levels of CmGalLDH mRNA in 20-d-old melon seedlings. To the authors' knowledge, this is the first report of GalLDH transcript induction in seed germination and differential gene expression during fruit ripening.

KW - Ascorbic acid

KW - Biosynthesis

KW - Cucumis melo L.

KW - Fruit development

KW - L-galactono-1,4-lactone dehydrogenase

KW - Melon

KW - Ripening

U2 - 10.1093/jxb/erh186

DO - 10.1093/jxb/erh186

M3 - Journal article

C2 - 15234991

AN - SCOPUS:4043078528

SN - 0022-0957

VL - 55

SP - 1623

EP - 1633

JO - Journal of Experimental Botany

JF - Journal of Experimental Botany

IS - 403

ER -