BIOL 114: The Effect of Humidity on Arabidopsis thaliana growth and development

Humidity and soil moisture levels can have a profound impact on plant growth. Optimal humidity between (60% - 70%) and optimal soil moisture (20 - 60%) exhibit the greatest effects. High humidity leads to negative impacts as it reduces the respiration rate, while low humidity levels will increase stomatal resistance, leading to a reduction of carbon dioxide uptake and photosynthesis. We used both wild-type and an unknown mutant form of Arabidopsis thaliana (25026) to examine humidity and soil moisture effects on plant growth and phenotypes. Plants grown under optimal humidity and soil moisture levels generally resulted in higher average plant diameter, however mutant 25026 showed no difference in growth compared to the wild-type.