Question

What are fungal hyphae and how do they grow?

Answer 1

• Hyphae are tube like structures or branching filaments which grow out from filamentous fungi and undergo repeated branching to form mycelium.
• Hyphae contains cell wall, cytoplasm, nuclei, ribosomes and other cell organelles and are required for fungal growth, nutrient absorption and transportation.
• Hyphae grow continuously at their tips by releasing enzymes which facilitate extension of tip(for eg. proteases which degrade pre existing cell wall). Biomolecules required for synthesis of new cellular structures are provided by pre existing (older) regions of hyphae.
• Enzymes released from hyphae diffuse resulting in formation of substrate erosion zones in vicinity of hyphae, creating zones of nutrient deficient zones. Hyphae tips from these nutrient deficient zones grow continuously maintaining funal growth.
• This direction oriented growth of hyphae is known as Apical Growth.
• Golgi bodies from older regions of hyphaeproduce apical vesicles containing enzymes required for cell wall lysis for eg. proteases, formation of new cell wall eg. glucan synthetase and chitin synthase, activators and inhibitors of enzymes eg. GTP which activates activates glucan synthetase by forming the characteristic structure known as spitzenkorper and release them along hyphae apex.