EXPRESSION AND REGULATION OF CELL CYCLE GENES IN UNDERGROUND ADVENTITIOUS BUDS OF LEAFY SPURGE (EUPHORBIA ESULA L.)

Authors: Chao, Wun; Anderson, James; Horvath, David; Shelver, Weilin; Foley, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2004
Publication Date: 2/9/2004
Citation: Chao, W.S., Anderson, J.V., Horvath, D.P., Shelver, W.L., Foley, M.E. 2004.Expression and regulation of cell cycle genes in underground adventitious buds of leafy spurge (Euphorbia esula L.) [Abstract]. Weed Science Society of America Annual Meeting.

Interpretive Summary: Leafy spurge is a deep rooted perennial weed that propagates vegetatively from an abundance of underground adventitious buds (UABs) located on the roots and crown and is the primary characteristic leading to its invasive nature. These buds develop during the normal growing season but are maintained in a quiescent state through correlative inhibition. Existing evidence indicates that growth-arrest may be a result of interactions between signaling pathways controlling dormancy and those controlling the cell cycle. To enhance our understanding of growth and development during vegetative propagation, we have cloned two cell cycle genes encoding CDK-activating kinase (CAK) and retinoblastoma (Rb) and a gene encoding cullin which is the component of a protein complex involving degradation of several cell cycle proteins. Antibodies for these proteins were generated. We have examined the expression and biochemical character of these genes and/or proteins using various molecular techniques. Current data shows that CAK, Rb, and cullin are expressed constitutively at both transcriptional and translational levels, indicating a preference of post-transcriptional regulation. In fact, CAK is activated through auto-phosphorylation. The details of these results will be reported.

Technical Abstract: Leafy spurge is a deep rooted perennial weed that propagates vegetatively from an abundance of underground adventitious buds (UABs) located on the roots and crown and is the primary characteristic leading to its invasive nature. These buds develop during the normal growing season but are maintained in a quiescent state through correlative inhibition. Existing evidence indicates that growth-arrest may be a result of interactions between signaling pathways controlling dormancy and those controlling the cell cycle. To enhance our understanding of growth and development during vegetative propagation, we have cloned two cell cycle genes encoding CDK-activating kinase (CAK) and retinoblastoma (Rb) and a gene encoding cullin which is the component of a protein complex involving degradation of several cell cycle proteins. Antibodies for these proteins were generated from maltose-binding-protein (MBP) fusion chimera, and affinity-purified using glutathione-S-transferase (GST) fusion chimera of the same proteins. We have examined the expression and biochemical character of these genes and/or proteins using RT-PCR, RNA and protein blot analysis, immunoprecipitation, and phosphorylation in dormant and non-dormant UABs of leafy spurge. Current data shows that CAK, Rb, and cullin are expressed constitutively at both transcriptional and translational levels, indicating a preference of post-transcriptional regulation. In fact, CAK is activated through auto-phosphorylation. The details of these results will be reported.