Growth and Vegetative Development
Gunawardena, Arunika N. , Voicu, Laura , Dengler, Nancy G. .
Are caspases and ethylene involved in PCD-remodeling of lace place leaves?
The lace plant, Aponogeton madagascariensis, uses programmed cell death (PCD) during leaf development in a quite different way than other plants. PCD remodels the leaves of the lace plant, forming a lattice pattern of equidistantly-positioned perforations at a set time in development. Therefore, lace plant is an attractive model system for studying developmentally-regulated PCD in plants. In this system, discrete populations of cells undergo a disruption of cytoplasmic streaming and loss of anthocyanin, indicators of tonoplast rupture, as well as DNA degradation and other cytoplasmic changes such as formation of vesicles, shrinkage and invagination of the membrane, and degradation of other organelles. Concurrently, adjacent cells are unaffected by these processes and develop normally. Unlike many other forms of plant PCD, cell wall degradation is a key event in lace plant PCD and is required for formation of the open perforations in the leaf blade. An ethylene biosynthesis inhibitor significantly inhibited perforation formation in cultured lace plant and detached leaves. The absence of perforation formation in leaves of whole plants and in detached leaves treated with the ethylene biosynthesis inhibitor AVG suggests ethylene may be an initial trigger in developmentally-regulated PCD in lace plant. Likewise, preliminary results using a caspase-1 inhibitor support the possibility that caspase-like proteases may be involved in PCD during perforation formation in lace plant. The interconnection between ethylene and caspase-like proteases in developmentally-regulated PCD in plants is under current study.
Log in to add this item to your schedule
1 - Dalhousie University, Biology, 1355, Oxford Street, Life Science Center, Halifax, NS, B3H 4J1, CANADA
2 - University of Toronto, Cells and Systems Biology
Programmed Cell Death
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM