Lec8Translocationnotes

Sieve elements general term sieve tube elements

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Sieve elements in general term. • Sieve elements (general term) – Sieve-tube elements (angiosperms), sieve cells (gymnosperms) • Sieve plate • Pores essentially open channels allowing bulk flow between cells • Membrane must stay intact and pores must remain open – No nucleus or tonoplast when mature Translocation these are the cells that are make the Phloem From: Front Plant Sci. 2012; 3: 151. Published online 2012 July 13. Prepublished online 2012 April 18. doi: 10.3389/fpls.2012.00151 Translocation © 2012 Jensen, Mullendore, Holbrook, Bohr, Knoblauch and Bruus. Structural Aspects • Companion cells every one these cells have companion cells every phloem sieve tube has a companion cells – Many plasmodesmata connections with sieve tube members – Take over some control of sieve tube member metabolic functions – Source of ATP Translocation Structural Aspects • P-protein (slime) sieve tube cell – Functions in sealing off damaged sieve elements, plugging pores – Rapid and temporary Translocation • Callose Structural Aspects – Beta-(1-3) glucan – Synthesized by protein in plasma membrane – Synthesized in response to damage or other stress – Long term sealing of Aniline Blue damage http://www.uni-graz.at/~huber/ http://pix.botany.org/ Translocation http://www.biologie.uni-hamburg.de Translocation Characteristics • Translocated substances...
View Full Document

Ask a homework question - tutors are online