Effects on Artemisia annua Growth with the Addition of Gibberellic Acid, Salicylic Acid, and Methyl Jasmonate in Hydroponic Systems

Malaria is a global health issue that will continue to spread with the increase in mosquito populations caused by the rise in global temperatures. The most effective drugs currently available for malaria treatment contain the anti-malarial compound, artemisinin, derived from Artemisia annua. To potentially increase efficiency of artemisinin production in A. annua, I investigated the effects of adding gibberellic acid, salicylic acid, and methyl jasmonate in hydroponics on the growth of intact plants. The goal of the study was to determine the optimal concentrations of each elicitor that maximizes the growth of A. annua, investigate the effects of different combinations of these elicitors on growth, and to determine the optimal exposure period of each elicitor that maximizes growth. I hypothesized that the concentrations of these chemicals that increased growth in previous studies would also yield the best results in hydroponic systems. Also, I hypothesized that the combination of all of these chemicals would yield maximum growth by inducing growth through different pathways. In terms of the optimal exposure periods, I hypothesized that the rate of growth would decrease over time and stabilize at around four weeks. My results show that the treatments containing gibberellic acid demonstrated the highest dry weights, suggesting that gibberellic acid enhances A. annua growth. In addition, the combination treatment with all three elicitors yielded the lowest dry weights. The data shows that the optimal exposure period for all elicitors and combinations was between 8 weeks and higher, except for individual salicylic acid treatments that showed the greatest growth between weeks 4 and 6. Future studies can expand on this study by investigating the relationship between A. annua growth and the addition of gibberellic acid.