Up-regulation of @entity369 decarboxylase gene expression and accumulation of @entity4663 in mustard ( XXXX )in response to stress.

@entity2656 @entity535 @entity8037 @entity7224 @entity4663 @entity4664 @entity13344 @entity369 @entity11667
@entity369 decarboxylase (ADC) is a key enzyme involved in the synthesis of @entity4663 , which have been implicated in a wide range of plant responses, including stress. However, regulation of @entity4664 levels in relation to ADC in response to stress at the molecular level is not well understood. In an attempt to address this question, we first cloned two cDNAs in mustard ( @entity13344 _ Coss var. @entity13344 ), designated MADC2 and MADC3, encoding predicted ADC. MADC2 and MADC3 encode polypeptides of 692 and 680 @entity535 residues, respectively. A comparison of deduced @entity535 sequence revealed that both were highly homologous to MADC1 (77%), a mustard ADC, and other plant ADCs (63-84%). Northern analysis revealed that ADC transcripts in mustard were generally more abundant in stem and root but were barely detectable in leaf. However, ADC expression in the leaf was up-regulated differentially in response to stress such as chilling, salt and @entity2656 and to treatments with exogenous @entity4663 . While chilling induced expression of all three ADC genes, salt predominantly resulted in increased accumulation of MADC3 transcript. Leaves exhibited a similar response to exogenous @entity7224 , @entity11667 and @entity8037 , all of which stimulated accumulation of MADC2 and MADC3 transcripts but not MADC1. Furthermore, exogenous @entity7224 also increased the endogenous levels of @entity11667 and @entity8037 , while a higher endogenous @entity7224 and @entity11667 content was detected in leaf incubated with exogenous @entity8037 . Leaves also responded to chilling, salt and @entity2656 by increasing the levels of the cellular @entity4664 content, in which the level of @entity8037 in free and conjugated forms increased most profoundly.
