ARS | Publication request: Molecular mechanisms responsive to dehydration may impact the invasiveness of perennial weeds under global climate change

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2012
Publication Date: N/A

Technical Abstract: Leafy spurge is an invasive perennial weed in the great plains of the US and Canada. The ability of this herbaceous weed to regenerate new shoot growth from an abundance of crown and root buds after severe abiotic stress is critical for survival. Due to its adaptable and aggressive nature, global climatic change has the potential to benefit the invasiveness of leafy spurge. To determine if the growth of crown and root buds is affected by dehydration-stress, a major component of the climatic change, leafy spurge was subjected to mild- and severe-dehydration treatments. Microarray analysis was then used to follow changes in molecular mechanisms in crown and root buds of plants exposed to dehydration treatments for 0-, 3-, 7-, 14- and 21-days. Transcriptome profiles revealed that 615 and 792 genes were differentially-expressed (P<0.005) in the crown and root buds, respectively, during dehydration treatments (0-21 days); 220 of these genes were common to both crown and root buds. Gene-set enrichment analyses was used to identify over-represented pathways and gene-ontologies, which included response to hormone stimuli, stress responses (heat shock, osmotic, oxidative, salt, and wounding), transport functions, carbohydrate degradation, binding (DNA and RNA, ion, and protein), cell cycle, and plant development. Further, sub-network enrichment analyses identified central hubs of over-represented genes involving mainly in stress and hormone responses (DREB2A, ETR1, JAZ10, MYC2), phosphorylation (MPK6, NDPK2), response to light (bHLH, PHYB), and gene silencing by microRNA (mir172A). Identification of these molecular mechanisms and their response to different levels of dehydration-stress may provide a better understanding of how leafy spurge adapts and survives under harsh environments. Further, the information may assist in devising management practices to reduce the spread and invasiveness of perennial weeds such as leafy spurge.