Translocation in phloem in your cursive.pptx

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1. BHARATHI COLLEGE (AUTONOMOUS) PG&RC BHARATHINAGHARA Paper name : Biochemistry and plant physiology Seminar topic: Translocation in phloem 2023-24 Presented by: Prakruthi S M 2nd M.Sc. Botany Bharathi college,PG & RC Bharathinaghara. Presented To: Srinidhi.M Assistant professor Department of Botany Bharathi college,PGand RC Bharathinagara.

2. Content Introduction Translocation in phloem Types of Translocation in phloem Mechanism of Translocation Conclusion Reference

3. Mechanism of translocation Munch' mass Flow hypothesis : T his hypothesis was proposed by E. Munch 1980 According to this theory organic solutes are conducted in mass from the site of production t o the site of consumption through sieve tube of phloem along the turgor pressure To explain this theory he made an osmotic model. The model consisted by two Osmometer A and B made up of semipermeable membrane. Osmometer A was filled with concentrated sugar solution and 'B' with diluted sugar solution. The two Osmometer were connected b y a g la ss tube T. Then they wer placed in a t rough containing water. Due to greater osmotic potential in the Osmometer A, water enters into A as a result the turgor pressure inside the increased. The re is mass f low of solution from ‘ A ' into 'B' through the glass tube T'

4. The process will continue till they attain same concentration.If the sugar in Osmometer ‘ B’is removed or converted Into Insoluble starch t hen there will be continuous flow of solution if it is increased in osmometer ‘A’ Osmometer A is compared to leaves ( supply end) Osmometer ‘B’ is compared to roots [sink] Glass tube ‘ T ’ is compared to s ie ve tube of phloem. Water In through corresponds to xylem element Mespphyll cells of leaves prepare prepare sucrose osmotic concentration increases hence they draws water from xylem of Leaf so their turgor pressure increases, This pressure pushes the sugar solution in mass through the Sieve Tube of leaves then through the stem into the roots where they are utilized or stored. Drawbacks :- It explains only unidirectional flow of organic solutes but it is bidirectional. Hypothesis. I s purely passive phenomenon but does not explain root of cytoplaan of seive tube. Turgor preasure may not always be hig he r at the supply end.

5. The conclusion on translocation in phloem is that it is a vital process for the transport of organic compounds, mainly sugars (produced during photosynthesis), from the leaves to various parts of the plant. This process ensures that all plant cells receive the nutrients they need for growth, energy, and storage. Phloem translocation occurs through the active movement of substances via a pressure-flow mechanism, driven by differences in water potential between source (usually leaves) and sink tissues (e.g., roots, flowers). This movement is facilitated by sieve tubes, companion cells, and other phloem elements, playing a critical role in plant nutrition and overall function. Conclusion

6. Molecular Biology of the Cell” by Bruce Alberts Pranav kumar & Usha mina Life Sciences Fundan-ntals and practice (part II)3rd edition (2010)Pathfinder publications, Page No: 224-225. Reference: https:// www.ncbi.nlm.gov .