Transfer Cells
Transfer cells occur at the interface between tissues; they are
specialized cells that facilitate transport (absorption or secretion) of
soluble substances across tissue boundaries. For example, they can occur at the
junction of the megagametophyte and mega-sporophyte, in companion cells in
phloem tissue (especially at the node of a stem), in root nodules, in the
haustoria of parasitic plants, and in the epidermis of water plants. Several cells of the embryo sac
and seed, including synergids, antipodals and specialized endosperm cells, have
been identified as transfer cells in different species. Transfer cells are
typically characterized by numerous cell-wall ingrowths protruding into their
protoplasts or those of adjacent cells; these ingrowths are sometimes visible
using light microscopy. Secretory cells, such as those of glandular hairs and
nectaries, also frequently possess wall ingrowths. The plasma membrane of the
transfer cell follows the contour of the wall ingrowths, thus increasing the
surface area.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.