Plant Sciences

Assessing the Biopharmaceutical Potential of a Halophytic Plant, Salicornia pacifica

Salicornia pacifica is a salt-tolerant plant endemic to the San Francisco Bay Area. Numerous studies show that other Salicornia species, namely S. bigelovii, have potential as sources of sustainable biofuel. Their tissues contain significant amounts of oil that can be converted into biodiesel. Halophyte benefits include that they thrive in harsh conditions and don’t compete with food fuel crops, like corn. This project investigates the biopharmaceutical potential of S. pacifica through phytochemical screening. Phytochemical presence would confirm S. pacifica as a truly multi-use plant to be cultivated on a large-scale basis. Both ethanolic (EE) and aqueous (AE) extracts of S. pacifica (Oaktown Nursery, Berkeley, CA) were prepared by oven-drying and grinding succulents. Biomass was either macerated for five days in 70.0% ethanol or heated for 25 minutes with distilled water at 30°C.

Wagner’s reagent was prepared and added to EE; reddish precipitate indicated alkaloids. Shinoda’s test involved adding 99.8% magnesium ribbon and 1.0M HCl to EE; a reddish hue implied flavonoids. In the froth test, deionized water was agitated with AE; presence of froth layer after waiting 30 seconds confirmed saponins. In Braymer’s phenol test, 1.0M FeCl3 was added to AE, anticipating a blueish color. When subject to four trials of each reagent, S. pacifica extracts displayed presence of saponins, flavonoids, phenols, and alkaloids. No Keller-Killani trials signified cardiac glycosides. Overall, the hypothesis was confirmed. Further studies can determine effects of environmental salinity on oil and phytochemical concentrations, which could be quantified via spectrophotometric methods.

The objective was to determine the habitability of Martian soil, and to compare and contrast what chemicals and materials would make Martian soil better suited for life in the future. Grass seeds were grown in individual cups, in sets of different mixtures and variations of Earth soil and Martian soil. Set A was our constant, 100% potting soil. Set B was 100% Martian soil. Set C was a mixture of 50% Martian soil and 50% potting soil. Set D was 25% Martian soil and 75% potting soil. Our final set, Set E, was a mix of 50% Martian soil, 25% potting soil, and 25% garden soil.

I measured the height of the tallest grass blade in each pot from the surface of the soil to the blade’s very tip. I did this for every single pot and recorded its height in cm. I continued this process weekly, and after about 5 weeks I measured the height of 5 grass blades per pot in cm and recorded their heights. At the end of the data collection, the 50% Martian Soil and 50% potting soil had the highest average plant growth. A mean height of about 12.13 cm. Based on our data, Martian soil is slightly less habitable than Earth potting soil. It is still very livable, but presents a couple obstacles that can hinder plant growth. However, when mixing 50% potting/Earth soil with Martian soil, you get a soil 23% as habitable as normal, plain potting soil.

The objective of this project was to assess the change in water-retention of soil after the addition of certain polyacrylates. The nutritional composition was determined based on the effect of anions in each polyacrylate. The two polyacrylates used were potassium and sodium. A total of 12 plants were used for each of polyacrylate. Out of these groups, 3 plants were controls, and the other plants contained either 2 grams, 4 grams, or 8 grams of polyacrylate. Every 3 days the plants were watered with 50 mL. A tensiometer was used periodically to measure water retention. To test the nutritional value of the plant, the juice of a tomato from each plant was extracted and held over a Bunsen flame to observe color changes. Overall, the plants with more polyacrylate had the highest moisture levels consistently before and after watering. After comparing both polyacrylates, the potassium variant demonstrated higher retention rates. Due to the structure of sodium, there was an increase in clumping near the plant roots that resulted in difficulty absorbing water. The sodium anion led to a slight change in the nutritional composition. The amount of sodium slightly increased, which was visible in the flame test. The potassium polyacrylate did not have any effect on the soil or the nutrition and therefore can be used for agricultural purposes safely. The results of this experiment can help further advance agriculture due to less water being needed to produce the same or better quality result.

With the expected human population to grow by over 2.5 billion people in 2050, one of the major problems facing humanity currently and in the future is properly feeding nearly 10 billion people. One of the prominent ways humanity could solve this crisis is through hydroponics, the science of growing plants without soil, having many revolutionary benefits for humanity including: requiring less space than conventional farming by stacking layers of plants, using 90% less water than regular farming using circulation, increasing crop yields by eliminating pests and diseases through sterile growing habitats, eliminating soil factors which allows plants to be grown in locations without good or any soil like space, desserts, and metropolitan cities. The objective of this experiment is to find the effect of the ratio of the NPK nutrient solutions (15-15-15 NPK, 20-10-10 NPK, 10-20-10 NPK, 10-10-20 NPK, 20-20-10 NPK, 20-10-20 NPK, 10-20-20 NPK) vs. no nutrient solution on the growth rate of basil in a Kratky-hydroponics environment. 1-inch Rockwool cubes were placed in net cups that were inserted into ½ gallon jars filled with water and periodically had the different nutrient solutions poured into the jar. The plants with nutrients all did better than the control of none with the exception of 10-20-20 NPK. Those with high levels of Nitrogen did the best, then those with high levels of Phosphorus and at last Potassium however all did better than 15-15-15 NPK and the control. In the future, more trials would increase the accuracy of this experiment. In the future, hydroponics will be a common practice and hydroponic farms using the perfect NPK ratio for the plants will be common in cities and impoverished districts and will be able to produce more healthy foods such as leafy greens to a far larger population possibly solving global hunger.