Introduction
Cells communicate by transferring molecules from one to another. When a molecule is transferred it creates a reaction which then causes an effect. Within multicellular organisms there is cell-to-cell communication. Direct communication between cells can occur in two ways. One way is cell-cell recognition via interaction between surface proteins. When there is contact between cell surfaces, the proteins on the surface of the cell interact and create a signal. The other way is through cell junctions between adjacent cells. In animals this is called gap junction, in plants it is called plasmodesmata. Plasmodesmata are microchannels that act as intercellular cytoplasmic bridges that create an interconnected commune within adjacent cells and enable transport of materials between plant cells. The plasmodesmata connects the symplastic space in plants. They are specialized channels that permit intercellular movement of water, various nutrients, and other molecules (including signalling molecules) (Epel, 1994). Myosin VIII, a plant specific unconventional myosin has been localized within the plasmodesmata(Reichelt et al, 1997). The role of this protein within the plasmodesmata has yet to be determined.
Background
Plant cells are surrounded by cell wall which separates neighboring cells.Plasmodesmata(PD) are located in areas in cell walls called primary pit fields. There is up to one million per square millimeter making up one percent of the entire area of the cell wall (Salisbury and Ross, 1992). There are two forms of PD, primary and secondary. Primary originates during cell division and remains in growing cells. Secondary PD are formed in mature plant cells. PD vary in formation as well. They can be simple, twinned, ...
... middle of paper ...
...lackman, L. (1996) A model of the macromolecular structure of plasmodesmata. Trends in Plant Science 1 (9):307-311.
Tilney, LG, Cooke, TJ, Connelly, PS, and Tilney MS. (1991) The structure of plasmodesmata as revealed by plasmolysis, detergent extraction, and protease digestion. The Journal of Cell Biology 112 (4):739-747.
Balusûka F, Cvrcûkova ́ F, Kendrick-Jones J, Volkmann D. 2001a. Sink plasmodesmata as gateways for phloem unloading. Myosin VIII and calreticulin as molecular determinants of sink strength? Plant Physiology 126, 39–46.
Knight AE, Kendrick-Jones J (1993) A myosin-like protein from a higher plant. J Mol Biol 231:143–154.
Reichelt S, Kendrick-Jones J (2000) Myosins. in Actin: A Dynamic Framework for Multiple Plant Cell Functions. eds Staiger CJ, Baluška F, Volkmann D, Barlow PW (Kluwer Academic Publishers, Dordrecht, The Netherlands), pp 29–44.
Digestion of the haemolytic and non-haemolytic cells allowed for easier identification of fragments during electrophoresis analysis. Lane 12 in figure 3 show the size markers of SPP1 digested with EcoR1 while lanes 6 and 7 show samples of pK184hlyA and pBluescript digested with EcoR1 and Pst1. Lane 4 was loaded with plasmid DNA from haemolytic cells digested with EcoR1 and Pst1 while lane 5 was loaded with EcoR1 and Pst1 digested DNA from non-haemolytic cells. There was a lack of technical success in both lanes due to no bands appearing in lane 4 and only a single band appearing in lane 5. Theoretically, two bands should appear in both lanes after successful to allow for fragment identification. A possible explanation for the single, large fragment in lane 5 is that successful digestion did not take place and the plasmid was only cut at one restriction site leaving a large linear fragment of plasmid DNA. The absence of bands in lane 4 could be because there was not enough plasmid loaded into the lane. Another possibility could be that low plasmid yield as obtained when eluting the experimental samples in order to purify it. Lanes 8 and 9 belonged to another group and show technical success as two bands were present in both the haemolytic (lane 8) and non-haemolytic (lane 9) lanes. If the
In this experiment, we perform a gel electrophoresis on the DNA. In this process, the enzymes were run through the gel electrophoresis to determine their relative sizes for each of them. The results of the certain DNA fragments are used in the final step, which is to construct a map of the DNA molecule. If we use different enzymes to cut DNA, then not every restriction site will be cut by all of the enzymes. The objective of this lab is to perform restriction enzyme of digesting plasmid DNA and constructing a map of plasmid from the results made from the experiment. Using this technique we understand what a DNA restriction enzyme is and how it works. In this process, the enzymes were run through the gel electrophoresis to determine their relative sizes for each of them. By following the experiment, we determined the positions of the restriction
Phosphorylation and dephosphorylation can activate or deactivate a protein but changing in 3-D conformation and as a result changing the ability to interact with other proteins. Just like in Arabidopsis and other an...
Xiaoli Dong, Paul Stothard, Ian J. Forsythe, and David S. Wishart "PlasMapper: a web server for drawing and auto-annotating plasmid maps" Nucleic Acids Res. 2004 Jul 1;32(Web Server issue):W660-4.
All eukaryotic plant cells that have coloured plastids contain their photosynthetic pigments in these membrane bound units [3]. In land plants, the facilitators of photosynthesis are the chloroplasts.
The plants that we know today as terrestrial organisms were not always on land. The land plants of today can be linked back to aquatic organisms that existed millions of years ago. In fact, early fossil evidence shows that the earliest land plants could have arisen some 450 million years ago (Weng & Chappie 2010). Plants that used to reside strictly in water were able to adapt in ways that allowed them to move onto land. It is speculated the need for plants to move onto land was created by water drying up, causing plants to have less room and pushing them to move onto land. Although the exact cause of plant’s need to move to a terrestrial environment is unclear, it is known that plants had to undergo several adaptations to be able to live on land. These adaptations include: lignin, cellulose, suberin, and changes to plant’s surface, including the formation of a waxy cuticle.
This finding led to conclude that the DMI3 gene may play an important role in the plant's response to calcium oscillations. It is necessary for Rhizobial and Mycorrhizal interactions and encodes a calcium and calmodulin-dependent kinase. In the process of working on nitrogen fixation, we have discovered a general method for identifying important plant genes that is fast and may be applicable to almost any plant species.
It consists of lipid envelope and nucleocapsid, which is icosahedral in shape and made up of proteins. DNA reverse transcriptase and vira DNA are enclosed in nucleocapsid. Proteins which are present on outer envelope functions for binding, entry and susceptible cells. Its diameter is 42 nanometer. Pleomorphic forms include, spherical and filamentous bodies which lack a core. They are non infectious particles because they are composed of lipids and proteins only.
This organelle is the site of photosynthesis in plants and other organisms. In the structure, the chloroplasts has a double membrane, the outer membrane has a continuous boundary. This organelle can be found in a vast group of organelles called the plastid, chloroplasts are usually found in many plant cells but never in animal cells. Chloroplasts organelles are large; they are 4-10um long and 2-3um wide. They are very important to plants because chloroplasts are what plants use to create food from sunlight. Chloroplasts are not found in humans.
I. Plasmids are important tools in molecular biology. Plasmids are small circular DNA that has the ability to enter and replicate in bacterial cells and can be used as vectors to introduce foreign genes into bacteria for cloning and sequencing. Any gene must be inserted into an appropriate location of a plasmid to be expressed. The importance of a plasmid is in the step of cloning and sequencing when the construction of a recombinant DNA molecule occurs. The target gene fragment is ligated to a plasmid, and becomes recombinant DNA. Then the plasmid can replicate autonomously in an appropriate host organism.
When there is water deficiency in plants, the concentration of abscisic acid in plants’ cells increases triggering the closure of stomata. Karp (2009) stated that “abscisic acid binds to a GPCR in plasma membrane of guard cells” (p.638). The receptors then activate several pathways in response to this condition. This attachment causes the opening of Ca2+ channels which transfer Ca2+ from vacuole into cytosol. At ...
Campbell, N. A. & J. B. Reece, 8th eds. (2008). Biology. San Francisco: Pearson Benjamin Cummings.
Osmosis is the passage of water molecules from a weaker solution to a stronger solution through a partially permeable membrane. A partially permeable membrane only allows small molecules to pass through, so the larger molecules remain in the solution they originated in. Solute molecule [IMAGE] [IMAGE] Water molecule [IMAGE] The water molecules move into the more concentrated solution. When water enters a plant cell it swells up. The water pushes against the cell wall and the cell eventually contains all that it can hold.
When plants such as seaweeds or others that grow under water, their parts are supported on all sides by hydrostatic pressure. There is not much difference in the density between plant cells and their surrounding liquid environment. Aquatic plants do not require significant structural support; their cell walls only contain polysaccharides, c...
J. Losos, K. Mason, S. Singer, based on the work of P. Raven, & G. Johnson, Biology, 8th ed., (McGraw-Hill Education (Asia), Singapore, 2008), pp. 994-995.