Mode of Nutrition in Plants

What are the different mode of nutrition of Plants?
prepared by Arnab Bashistha,!st Sem,Bajali College'14

1. MODE OF NUTRITION in plants by Arnab bashistha Botany major 1 st sem Bajali college’14

2. What is Nutrition: It is the process of taking in of food. The energy which is stored within the food materials is used by the living organisms for various activities. Nutrition occurs in several stages like ingestion, digestion, absorption, assimilation and egestion.

3. Mode of nutrition in plants: Photosynthesis is a type of plant nutrition carried out by green plants only.All the plants can not get their nourishment through the process of photosynthesis. Some plants are dependent on other plants and animal for their food. Different plants have different nutritional processes .

4. Classification of plants on the basis of mode of nutrition: Autotrophs: Epiphytes Chemoautotrophs Heterotrophs: Parasites Saprophytes Symbiont Insectivorous Plants

5. autotrophs The autotrophic plants are all green plants by virtue of the presence of chlorophyll in their cells.As they can produce their food from inorganic materials, they are not dependent on other plants or animals for food. According to different habitat and environmental conditions autotrophs have structural differences.They range from unicellular type (algae e.g. Chlamydomonas ) to large branched trees. Epiphytes ( e.g. some orchids ) are a kind of autotrophs which only live on other plants but do not take any food from that plant.

6. chemoautotrophs They prepare their own food by the process of chemosynthesis i.e. the process of carbohydrate formation in which chemical reaction is used to obtain energy from inorganic compounds. Example: Sulphur bacteria like Beggiatoa convert H 2 S to Sulphur and releases enegy . 2H 2 S + O 2 2H 2 O + 2S + energy

7. Heterotrophs The heterotrophic plants are incapable of photosynthesizing.They are non-green i.e. they lack of chlorophyll.They obtain certain organic compounds (food) from other autotrophs. They may be saprophytes, parasites, symbionts or insectivorous.

8. Saprophytes: They get their nutrition from dead or decaying organic matter. They may be obligate saprophytes (i.e. they can live only on dead organic matter) or facultative saprophytes (i.e . they are mainly parasitic organism with the ability to survive for a part of its life cycle as a saprophyte). Examples: Neottia , Monotropa etc.

9. Parasites: They get their nutrition from the host.The parasites maintain their physical contacts with the host plant through haustoria (parasitic roots). Parasites may be of two types- Obligate parasite (i.e. they are parasitic organism that can’t completes its life cycle without exploiting a suitable host) and Facultative parasite (i.e. they may resort to parasitic activity but absolutely rely on any host for completion of its life cycle). They may live on the stem or on the roots of the host.They may be partially autotrophic and partially parasitic.On this basis parasites are – a. Total stem parasite b. Partial stem parasite c. Total root parasite d. Partial root parasite

10. a. Total stem parasite: They totally depend on the host plant as they lack of chlorophyll.Example : Cuscuta b . Partial stem parasite: They depend on the host plants only for water and minerals, but they bear chlorophyll and get nutrition through the process of photosynthesis.Example : Viscum

11. c. Total root parasite: They live on the roots the host and get their nourishment.Example : Raflessia , Orobanchae d . Partial Root Parasite: They possess chlorophyll but for germination of their seeds they follow parasitism on roots of the host.Example : Santalum album

12. Symbionts : It means the close association between two different plants of different categories.In this association both the plants get benifited . Examples: Lichen(association between algae and fungi), Mycorrhiza (fungal association with the roots of higher plants) etc.

13. Insectivorous Plants: They have the mechanism to trap insects and are adapted to digest the protein matter contained in insects.They depend only partially on nutrition as they bear normal leaves and roots. Examples: Nepenthes, Drossera , Dionea , Utricularia etc.

14. Let’s See how the hero kills the villain

15. Thank You