![]() To form cuticular wax components, VLCFAs are modified through either two identified pathways, an acyl reduction pathway or a decarbonylation pathway. An important catalyzer thought to be in this process is the fatty acid elongase (FAE) complex. The first step of the biosynthesis pathway for the formation of cuticular VLCFAs, occurs with the de novo biosynthesis of C16 acyl chains (palmitate) by chloroplasts in the mesophyll, and concludes with the extension of these chains in the endoplasmic reticulum of epidermal cells. Also present are other compounds in cuticular wax which are not VLCFA derivatives, such as terpenoids, flavonoids, and sterols, and thus have different synthetic pathways than those VLCFAs. Cuticular wax biosynthesis Ĭuticular wax is known to be largely composed of compounds which derive from very-long-chain fatty acids (VLCFAs), such as aldehydes, alcohols, alkanes, ketones, and esters. The cuticular membrane is impregnated with cuticular waxes and covered with epicuticular waxes, which are mixtures of hydrophobic aliphatic compounds, hydrocarbons with chain lengths typically in the range C16 to C36. The cuticle can also contain a non-saponifiable hydrocarbon polymer known as Cutan. Cutin, a polyester polymer composed of inter-esterified omega hydroxy acids which are cross-linked by ester and epoxide bonds, is the best-known structural component of the cuticular membrane. The cuticle is composed of an insoluble cuticular membrane impregnated by and covered with soluble waxes. It is also present in the sporophyte generation of hornworts, and in both sporophyte and gametophyte generations of mosses The plant cuticle forms a coherent outer covering of the plant that can be isolated intact by treating plant tissue with enzymes such as pectinase and cellulase. Meristem Cell : Stem cell found in a plant meristem.The plant cuticle is a layer of lipid polymers impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants. Meristem : A small area of undifferentiated cells in a plant, such as near the shoot tips and root tips, where cells are dividing rapidly by mitosis. Rejection : When the immune system attacks and kills cells and tissue that come from another person, such as blood (after transfusion) or stem cells. Growth : A permanent increase in the number or size of cells in an organism.Īdult Stem Cell : Stem cell found in specialized tissue that can produce more of the specialised cells in that tissue for growth and repair. Stem Cell : Unspecialised cell that continues to divide by mitosis to produce more stem cells and other cells that differentiate into specialised cells.Įmbryonic Stem Cell : Stem cell from an early embryo that can produce specialised cells of many different types.Įlongation : When something gets longer (such as a cell in a plant root or shoot before it differentiates into a specialised cell). ![]() ![]() ![]() Percentile : A 1/100th division of a group.Ĭancer : Disease caused by the uncontrolled division of stem cells in a part of the body.ĭifferentiate : To change into different types, for example when meristem cells differentiate into specialised cells such as xylem or root hair cells. the vessels carry water and dissolved mineral salts through the plant. Xylem Cell : Cell that joins with other xylem cells to form long, thick-walled vessels after they die. ![]() Root Hair Cell : Cell found on the surface of plant roots that has a large surface area to absorb water and dissolved mineral salts quickly from the soil.ĭifferentiation : When a group of similar things, such as cells, become different in form from each other. ![]()
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