Question

What propels the movement of chemicals like carbohydrates through the hyphal cells of the fungus and then can you provide a reasonable sequence of steps for a fungus to establish a symbiotic relationship with plants?

Answer 1

Ans .The digestive enzymes that are released by hyphal tips into the medium and these diffuses out ahead of the fungus to break down the starch into glucose ( a simple carbohydrate) readily assimilated by fungus for its nutritional needs. This act of digestion outside the cell and absorption of breakdown products is called extracellular digestion and is accomplished through extracellular enzymes.

In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning are also influenced by cytoplasmic streaming toward the hyphal tip.

A mycorrhiza is a symbiotic association between a fungus and a plant.The plant makes organic molecules such as sugars by photosynthesis and supplies them to fungus, and the fungus supplies to the plant water and mineral nutrients such as phosphorus, taken from the soil. In a mycorrhizal association, the fungal colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi, or extracellularly as in ectomycorrhizal fungi.

The process of infection of host roots is characterized by distinct stages involving a number of complex morphogenetic changes in the fungi : spore germination , hyphal differentiation, appressorium formation, root penetration, intercellular growth and arbuscle formation.