The secondary phloem of pecan is segmented by narrow rays into radial sectors of varying width. Irregular bands of fibers alternate with tangential blocks containing sieve tubes, companion cells, and ...

These are distributed differently in roots and stems. In the root, the xylem forms a central column. It forms a solid support. The phloem is towards the centre, outside the xylem. Any green part ...

Specialised plant cells include root hair, palisade, xylem and phloem cells. Find out more with Bitesize. For students between the ages of 11 and 14.

AAP2 T-DNA insertion lines showed changes in source-sink translocation of amino acids and a decrease in the amount of seed total N and storage proteins, supporting AAP2 function in phloem loading and ...