Characterization of Mutant Aspergillus niger and the Impact on Certain Plants

Aspergillus niger is a dangerous pathogen for many plants. It is a major cause of the destruction, rotting and decomposition of plant tissues. Toxicity caused by A. niger can be inhibited by mutation decreasing the destructive effect on plants. An 18S rDNA molecular tool was used to identify A. niger strains. Sodium azide (NaN3) is a chemical mutagen that disturbs fungal enzymatic activity and causes microbial production of cellulose-degrading enzymes, decreasing mycotoxin production. Different concentrations of sodium azide were used to treat A. niger (30, 40 and 50 mu M). The study was designed on two levels: the first level concerned the mutant A. niger's mode of action: the higher the mutagen concentration, the lower the growth diameter and spore counts. The mutant A. niger's total proteins and flavonoids were reduced when compared to control. RAPD-PCR showed genetic variation in the genetic content of mutant fungi compared to control resulting in a polymorphism percentage of 78.56%. The second level included the effect of these mutants on two plants (onion and maize). The greater the increase in mutant concentration, the greater the increase in the plants' morphological and physiological behavior. In conclusion, mutation reduced fungal activity and strengthened plant resistance.

Automated summary

Aspergillus niger is a dangerous pathogen that can cause destruction and decomposition of plant tissues. The study conducted experiments using a chemical mutagen, sodium azide, to inhibit the toxicity of A. niger. The results showed that mutation reduced fungal activity, resulting in decreased growth diameter and spore counts, as well as reduced total proteins and flavonoids. The mutant A. niger strains also showed genetic variation compared to the control. Additionally, the mutants had a positive effect on the morphological and physiological behavior of onion and maize plants.