The effects of cold-shock at 4oC and hyphal growth rate on Neurospora crassa were investigated in this study. The mechanisms responsible for controlling hyphal extension and branching at various conditions are still poorly understood. Our experiment was trying to find the relationship between the hyphal growth rate and cold-shock. In addition, the protein analysis at different time phase of cold-shock was also being compared. Length of a selected hyphal tip in 20 minutes of Neurospora crassa has been measured after 0 min cold-shock (control), 45 min cold-shock and 90 min cold-shock in 2 separate trials. In trial one, the mean growth rate of 0, 45, and 90 min cold-shock were 24.4, 14.6, and 9.53 um/min respectively. In trial two, the mean growth rate of 0, 45, and 90 min cold-shock were 33.7, 9.13, and 5.92 um/min respectively. The results showed that there was a significant difference between the hyphal growth rate and cold-shock on Neurospora crassa and it appeared that longer the cold-shock, slower the hyphal growth rate.
It is concluded that various time phase of cold-shock reduced the metabolic activity level and therefore, inhibits the hyphal growth rate of Neurospora crassa.
Many factors could affect the metabolic level of Neurospora crassa, but among other factors, cold-shock exerts an important constraint on hyphal growth rate of Neurospora crassa (Park et al. 1997). Also, the mechanisms responsible for controlling hyphal extension and branching at various conditions are still poorly understood (Watters et al. 2000). Therefore, the trend of Neurospora crassa branching under different time phase of cold-shock will also be observed in this experiment. In addition, the branching of Neurospora crassa leads to increased secretion of certain proteins (Lee et al. 1998). As a result, the protein extraction will be performed for one of the trials.