![WELCOME
TO
PLANT ANATOMY
Wall Ingrowths and Transfer Cells
Presented By
DR. REYAZ A. MIR
[M.Sc., M.Phil., Ph.D. Botany]](https://image.slidesharecdn.com/ingrowthandtransfercell-240430132444-ab6679cf/85/Ingrowth-and-Transfer-Cell-pdf-This-ppt-represents-the-wall-ingrowth-and-role-of-transfers-cell-in-plant-growth-and-development-1-320.jpg)
Ingrowth and Transfer Cell.pdf. This ppt. represents the wall ingrowth and role of transfers cell in plant growth and development..
- 1. WELCOME TO PLANT ANATOMY Wall Ingrowths and Transfer Cells Presented By DR. REYAZ A. MIR [M.Sc., M.Phil., Ph.D. Botany]
- 2. OBJECTIVES ❖ Cell Wall Ingrowth – Definition ❖ Adcrustation and Incrustation with Examples ❖ Transfer Cells, their types, characteristics, and functions.
- 3. CELL WALL – INGROWTHS ❖ Wall ingrowths are considered specialized form of secondary wall ❖ These ingrowths develop late in cell maturation and are deposited on the original primary cell wall. ❖The wall ingrowths form just as intensive transport begins and are best developed on the cell surfaces that are involved in active solute transport. ❖This deposition takes place in two different ways : I. Adcrustation: growth comes from the whole body. II. Incrustation: grow with the addition of new layers on the surface of the body.
- 4. ADCRUSTATION ▪ It is the process in which the outer walls of the epidermis of leaves and other aerial regions, the walls of cork cells, certain walls of inner sheaths in roots and shoots are covered or impregnated by cutins and suberins. ▪ Cutin & wax occur on the outer epidermal surfaces of plant parts, leaves, stem and roots and is responsible for the hydrophobic characters of cuticle and to hinder evaporation particularly in the xerophytes. ▪ Suberin a 20 – 30 carbon atoms of long fatty acids and polyphenols, and present in cork cells walls, endodermal and exodermal ells of roots and bundle sheath cells enclosing the leaf veins of many of the cyperaceae, junacaceae and Poaceae. And prevent water loss by blocking apoplastic pathway and prevents pathogenic attack. ▪ Suberization also alters permeability of the cell walls.
- 5. INCRUSTATION ▪ When certain organic molecules penetrate the primary wall and undergoes polymer formation, the cell wall undergoes incrustation. ▪ The cell wall of the plants grow by the process of incrustation. ▪ Lignin is the most important incrusting substances and it is insoluble constituent of the cell wall, aromatic and of high molecular weight. ▪ It occurs predominantly in the region of the middle lamellae. ▪ Incrustation with lignin decreases the water permeability of the wall and the lignin deposits add mechanical strength.
- 6. (A) DEPOSITION OF WALL INGROWTHS (B) CELL WALL INGROWTHS
- 7. TRANSFER CELLS – WALL INGROWTHS ❖ The transfer cells first coined by Brain E.S. Gunning & John Pate (1969) are characterized by enlarged lobed nucleus, numerous ER Cisternae, numerous mitochondria and ribosome. ❖Transfer cells are specialized parenchyma cells containing cell wall ingrowths, which greatly increases the surface area of the plasma membrane. ❖ Plasmodesmata connect transfer cells to other transfer cells and to parenchyma cells.
- 8. TRANSFER CELLS – CHARACTERS ▪ Morphologically two categories of Wall ingrowths can be recognized in the transfer cells ; I. Reticulate – type II. Flange – type ▪ They occur in a wide range of locations in plant body: ▪ Xylem and phloem of minor veins in cotyledons and leaves of herbaceous eudicots. ▪ Tissues of reproductive structures (placentae, embryo sacs, aleurone cells, endosperms) and root nodules. ▪ Besides, transfer cells are induced to form by external stimuli against pathogen attack in plants that lack transfer cells. ▪ Due to such characteristics these cells have intensive role in short distance transport.
- 9. Transfer Cells – Growth (A) Hypothetical model of cellular processes and signals determining ETC differentiation from cell specification to the establishment of Transfer cell morphology. (B) Morphologically Wall ingrowths and transfer cell formation, their role in Storage of starch in MAIZE ENDOSPERM B A
- 10. TRANSFER CELLS – FUNCTIONS ❑ The transfer cells functions relate to any of the four categories of transmembrane flux as follows: I. Absorption of solute from the external environment like epidermis of the submerged leaves. II. Secretion of solutes to the external medium like nectaries and other glands. III. Absorption of solutes from the internal, extra cytoplasmic compartment like vascular parenchyma, haustorial type connections, embryo sac. IV. Secretion of solutes into an extra cytoplasmic compartment like tapetum of anther, pericycle of root nodule etc. V. Besides, the transfer cells form an anti-pathogenic barrier at the symplastic discontinuities. As the transfer cells help in nutrient transport, they are important in plant development and crop productivity.
- 11. • References/Source: • Plant anatomy – Esau’s • Slide Share.net • Frontiers in Plant Science – Transfer Cells – by David McCurdy and Gregorio Hueros
- 12. THANK YOU