MCDB 1B Lecture 12: Plant Physiology (Pt 2)
6 Mar 2018
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Document Summary
Stable food supply provided by agriculture sustains enormous population growth. Globally, more than one billion people per year are chronically hungry. Plant scientists can contribute to the alleviation of hunger by developing plants that. Plant growth is often limited by drought stress. Phase 1 (pre-civilization - 1600s): descriptive identification/recognition/cultivation of useful plants. Phase 3 (late 1990s present): genomics revolution is providing avalanche of information shift toward analysis of interacting systems rather than isolated processes. Vesicles fuse to form middle lamella (with some gaps) Daughter cells secrete wall material at plasma membrane surface. Cell position fixed - no cell migration (fixed position establishes age gradient) Cell position reflects lineage, body is age gradient. Growth depends on turgor (hydrostatic pressure) to stretch walls. ~ 30x larger pore size than gap junctions. gating alters effective pore size, changes connectivity during plant"s life. Plasmodesmata connections are maintained in pit fields of secondary walls.
