Senescence-associated down-regulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase delays harvest-induced senescence in broccoli.

To gain an in-depth understanding of the role of ethylene in post harvest senescence, we used broccoli (Brassica oleracea var. italica) as our model species. The senescence-associated asparagine synthetase (AS) promoter from asparagus was used to drive the expression of an antisense 1-aminocyclopropane-1-carboxylate oxidase (ACO) cDNA from broccoli, BoACO2, to reduce ethylene production following harvest.

Distinct cis-elements in the Asparagus officinalis asparagine synthetase promoter respond to carbohydrate and senescence signals.

The Asparagus officinalis L. asparagine (Asn) synthetase (AS) promoter was analysed for elements responding to carbohydrate and senescence signals. Transgenic Arabidopsis thaliana L.

Analysis of the asparagus (Asparagus officinalis) asparagine synthetase gene promoter identifies evolutionarily conserved cis-regulatory elements that mediate Suc-repression.

In asparagus (Asparagus officinalis L.), increased levels of asparagine (Asn) and Asn synthetase (AS) transcript are detected during foliar senescence and in harvested spears, possibly triggered by signals from a reduced supply of carbohydrate. To identify cis-elements mediating this regulation, the asparagus AS gene promoter was isolated and analysed by DNA sequencing, followed by expression of AS::GUS (β-glucuronidase) reporter-gene constructs in transgenic tissue, and electrophoretic mobility shift assays (EMSA).

Molecular analysis of programmed cell death during senescence in Arabidopsis thaliana and Brassica oleracea: cloning broccoli LSD1, Bax inhibitor and serine palmitoyltransferase homologues.

This study was undertaken to characterize the programmed cell death (PCD) processes that occur during detached and natural on-plant senescence and correlate them with the expression of putative regulatory genes that may be involved in the process. DNA fragmentation and TUNEL analysis of broccoli florets showed that DNA was processed into fragments of approximately 180 bp after 48 h of harvest-induced tissue senescence. Characteristic laddering patterns were also visible in Arabidopsis leaves undergoing natural on-plant senescence and during detached senescence.

Identification of dehydration-responsive cysteine proteases during post-harvest senescence of broccoli florets.

Harvest-induced senescence of broccoli results in tissue wilting and sepal chlorosis. As senescence progresses, chlorophyll and protein levels in floret tissues decline and endo-protease activity (measured with azo-casein) increases. Protease activity increased from 24 h after harvest for tissues held in air at 20 degrees C.

Controlled atmospheres and sugar can delay malate synthase gene expression during asparagus senescence.

A cDNA clone encoding malate synthase (MS; EC 4.1.3.