Abstract Detail

Population Genetics/Genomics

White clover cyanogenesis: dual benefit or double-edged sword?

Cyanogenesis (releasing HCN) is well documented as a chemical defense adaptation to deter herbivores in plants. As HCN is toxic to most of the living cells, cyanogenic plants use a two-component defense system which separates inert cyanide precursors, from their hydrolyzing enzyme, in different sub-cellular spaces. The HCN is only released If the tissue is damaged. However, as a small molecule, HCN can diffuse fast from the damaged tissue and affect the nearby healthy tissue. Therefore, we speculate that cyanogenic plants should have higher HCN recycling and tolerance ability than non-cyanogenic plants. Recent studies also show that the HCN recycling pathway can also serve as sources of reduced nitrogen in primary metabolism, and they may be especially valuable in drought prone environments. In this study, we use Trifolium repens, a species with intra-specific polymorphism of cyanogenesis, to investigate the gene regulation of the HCN recycling and tolerance pathway. We found that the HCN recycling and tolerance pathway are continuously regulated at a higher level in the cyanogenic T. repens than the non-cyanogenic T. repens. In addition, both pathways are not inducible by tissue damages. The result implies that T. repens can actively recycle HCN even when the tissue is not damaged; its effect on the overall fitness is still unknown. In the future, we are going to focus on the impact of cyanogenesis on drought tolerance in T. repens.

1 - Washington University In St Louis, Biology, 1 Brookings Dr, St Louis, MO, 63130, United States

Keywords:
Trifolium
cyanogenesis
polymorphism
gene expression
Plant Defenses.

Presentation Type: Oral Paper
Number: PGG2006
Abstract ID:724
Candidate for Awards:Margaret Menzel Award