Differential expression of the ascorbate oxidase multigene family during fruit development and in response to stress

TY - JOUR

T1 - Differential expression of the ascorbate oxidase multigene family during fruit development and in response to stress

AU - Sanmartin, Maite

AU - Pateraki, Irene

AU - Chatzopoulou, Fani

AU - Kanellis, Angelos K.

AU - Pateraki, Eirini

PY - 2007/3/1

Y1 - 2007/3/1

N2 - Ascorbate oxidase (AO, EC 1.10.3.3) is a member of the multicopper oxidases family. It catalyzes the oxidation of ascorbic acid (AA) to dehydroascorbic acid (DHA) via monodehydroascorbate (MDHA), with the concomitant reduction of molecular oxygen to water. In melon (Cucumis melo), ascorbate oxidase is encoded by a multigene family comprising at least four genes. Here, we present the detailed characterization of two melon AO genes, CmAO1 and CmAO4. Gene-specific expression studies of the AO gene family in melon revealed that only CmAO1 and CmAO4 are transcriptionally active and differentially regulated dependent on tissue, developmental stage and external stimuli. Transcripts of the CmAO1 gene are present in floral and fruit tissues, whereas CmAO4 mRNA preferentially accumulates in vegetative tissues. CmAO genes were not detected in melon seeds, but CmAO4 expression is activated upon germination. CmAO4 mRNA steady-state levels are also regulated in response to wounding and heat stress, by hormones (abscisic acid, salicylic acid and jasmonates), AA and copper. These findings suggest that AO gene expression is transcriptionally regulated during fruit development and in response to hormonal cues associated with the control of cell growth and the stress response.

AB - Ascorbate oxidase (AO, EC 1.10.3.3) is a member of the multicopper oxidases family. It catalyzes the oxidation of ascorbic acid (AA) to dehydroascorbic acid (DHA) via monodehydroascorbate (MDHA), with the concomitant reduction of molecular oxygen to water. In melon (Cucumis melo), ascorbate oxidase is encoded by a multigene family comprising at least four genes. Here, we present the detailed characterization of two melon AO genes, CmAO1 and CmAO4. Gene-specific expression studies of the AO gene family in melon revealed that only CmAO1 and CmAO4 are transcriptionally active and differentially regulated dependent on tissue, developmental stage and external stimuli. Transcripts of the CmAO1 gene are present in floral and fruit tissues, whereas CmAO4 mRNA preferentially accumulates in vegetative tissues. CmAO genes were not detected in melon seeds, but CmAO4 expression is activated upon germination. CmAO4 mRNA steady-state levels are also regulated in response to wounding and heat stress, by hormones (abscisic acid, salicylic acid and jasmonates), AA and copper. These findings suggest that AO gene expression is transcriptionally regulated during fruit development and in response to hormonal cues associated with the control of cell growth and the stress response.

KW - Ascorbate oxidase

KW - Cell expansion

KW - Cucumis melo

KW - Fruit development

KW - Fruit ripening

KW - Gene expression

KW - Heat stress

KW - Jasmonic acid

KW - Melon

KW - Wounding

U2 - 10.1007/s00425-006-0399-5

DO - 10.1007/s00425-006-0399-5

M3 - Journal article

C2 - 17021803

AN - SCOPUS:33847266379

SN - 0032-0943

VL - 225

SP - 873

EP - 885

JO - Planta Medica

JF - Planta Medica

IS - 4

ER -