Format

Send to

Choose Destination
Plant Physiol. 2008 Aug;147(4):2096-106. doi: 10.1104/pp.108.123273. Epub 2008 Jun 26.

Silencing onion lachrymatory factor synthase causes a significant change in the sulfur secondary metabolite profile.

Author information

1
National Centre for Advanced Bio-Protection Technologies, Lincoln University, Christchurch 7647, New Zealand. eadyc@crop.cri.nz

Abstract

Through a single genetic transformation in onion (Allium cepa), a crop recalcitrant to genetic transformation, we suppressed the lachrymatory factor synthase gene using RNA interference silencing in six plants. This reduced lachrymatory synthase activity by up to 1,544-fold, so that when wounded the onions produced significantly reduced levels of tear-inducing lachrymatory factor. We then confirmed, through a novel colorimetric assay, that this silencing had shifted the trans-S-1-propenyl-l-cysteine sulfoxide breakdown pathway so that more 1-propenyl sulfenic acid was converted into di-1-propenyl thiosulfinate. A consequence of this raised thiosulfinate level was a marked increase in the downstream production of a nonenzymatically produced zwiebelane isomer and other volatile sulfur compounds, di-1-propenyl disulfide and 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, which had previously been reported in trace amounts or had not been detected in onion. The consequences of this dramatic simultaneous down- and up-regulation of secondary sulfur products on the health and flavor attributes of the onion are discussed.

PMID:
18583530
PMCID:
PMC2492635
DOI:
10.1104/pp.108.123273
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center