Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Plant cell
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
===Phloem=== [[Phloem]] is a specialised tissue for food transport in higher plants, mainly transporting [[sucrose]] along pressure gradients generated by osmosis, a process called [[Phloem#Function|translocation]]. Phloem is a complex tissue, consisting of two main cell types, the [[sieve tube element|sieve tubes]] and the intimately associated [[companion cell]]s, together with parenchyma cells, phloem fibres and sclereids.<ref name=Cutter/>{{rp|171}} Sieve tubes are joined end-to-end with perforated end-plates between known as ''[[sieve plate]]s'', which allow transport of photosynthate between the sieve elements. The sieve tube elements lack [[cell nucleus|nuclei]] and [[ribosome]]s, and their metabolism and functions are regulated by the adjacent nucleate companion cells. The companion cells, connected to the sieve tubes via [[plasmodesmata]], are responsible for loading the phloem with [[sugar]]s. The [[bryophyte]]s lack phloem, but [[moss]] [[sporophyte]]s have a simpler tissue with analogous function known as the leptome. [[File:Epidermal Cells of Plant Leaf..jpg|thumb|This is an electron micrograph of the epidermal cells of a Brassica chinensis leaf. The stomates are also visible.]]
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)