Fungi : Mode of Nutrition in Fungi

In this article we will discuss the Mode of Nutrition in Fungi (1) Saprophytes (2) Parasites (3). Symbionts (4). Predacious fungi

  • Fungi are heterotrophic in nutrition
  • They are chlorophyll deficient plants and hence they cannot manufacture carbohydrates using carbon dioxide, water and sunlight
  • Fungi are with simple structural organization, thus they always depends on dead or living organic matter for their energy requirements
  • On the basis of mode of nutrition, fungi are classified into four groups:

  1. Saprophytes
  2. Parasites
  3. Symbionts
  4. Predacious fungi

(1). Saprophytes

Saprophytes fungi

  • Saprophytic fungi obtain nutrition from dead organic matter
  • These fungi lives on dead organic matter or excreta of both plant and animal origin
  • Examples: Mucor, Rhizopus, Penicillium and Aspergillus
  • Vegetative hyphae of these fungi directly absorb food materials from organic matter
  • Saprophytic fungi may be of two types:-

  1. Ectophytic saprophytes: grown on the surface of organic matter
  2. Endophytic saprophytes: grown inside the organic matter

  • In some ectophytic fungi such as Rhizopus, special absorptive structures such as rhizoids are developed for the easy absorption of food materials
  • Saprophytic fungi produce exo-enzymes (enzymes which acts outside the cell)
  • These enzymes digest the complex organic matter in the substratum into simpler compounds to facilitate easy absorption by the hyphae

(2). Parasites

Nightmare Parasitic Fungi Attacks

  • Parasitic fungi take food from other living plants or animals
  • The living organism on which the fungi parasitize are called host
  • Parasitic fungi are harmful to the host and they produce disease condition in host organisms
  • The relationship of host and parasite in pathology is known as parasitism
  • Parasitic fungi are of three types:-

  1. Obligate parasites: these fungi can live only as parasite on a living host Obligate parasites cannot live on dead organic matter Example: Puccinia which cause rust disease in several crop plants including wheat
  2. Facultative saprophytes: They are parasites, but they can also survive on dead organic matter in the absence of living host Example: Taphrina
  3. Facultative parasites: these fungi usually follow saprophytic mode of nutrition Under certain conditions, they parasitize suitable host plants Example: Fusarium and Pythium which cause soft rot disease in crop plants

  • On the basis of location of parasite in host organism, the parasites may be:

  1. Endoparasite: parasite live inside the host tissue
  2. Ectoparasite: parasite fungi which live on the outside surface of host

  • Parasitic fungi possess specialized absorptive structures called haustoria for the absorption of nutrients from the host cells
  • Haustoria are specialized hyphal modifications
  • Haustoria may be inter-cellular (occupy between two cells) in intra-cellular (occupy
  • within the cell)
  • Size and shape of haustoria varies in different fungal groups
  • Haustoria may be round, knob like, club like or branched

(3). Symbionts

Symbionts fungi

  • These fungi grow on or with other living organism but both of them are mutually benefited
  • Lichens and mycorrhiza are examples
  • Lichens are the symbiotic association between algae and fungi
  • Here both fungi and algae are mutually benefited
  • Algae synthesize carbohydrates where as the fungi provides shelter for algae
  • Mycorrhizae are the symbiotic association between fungi and roots of some higher plants
  • Mycorrhizae helps in the absorption of nutrients by the host plant
  • Mycorrhiza may be ectophytic or endophytic
  • Ectophytic mycorrhiza are external mycorrhiza and they are confined to the outer region of the roots
  • Endophytic mycorrhiza are internal mycorrhiza and they are found deeply in the root cells

(4). Predacious fungi

Predacious fungi

  • They are animal capturing fungi (predators)
  • These types of fungi possess special hyphal traps called snares to tap and capture small animals such as nematodes and protozoa
  • They usually inhabit in the soil
  • They possess rapidly constricting hyphal traps which hold the captive for long time
  • They also have haustoria which directly inserted into the tissue of the prey
  • Some predacious fungi also produce sticky secretions for capturing nematodes
  • Examples of predator fungi: Arthrobotrys, Dactylella, Dactylaria

Fungi : Mode of Nutrition in Fungi Fungi : Mode of Nutrition in Fungi Reviewed by Rajkumar on October 30, 2017 Rating: 5

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