Maya Rudolph Alabama A&M University REU-China Research and Cultural Experience 本科生研究經驗 Mentors: Dr. Malinda Gilmore-AAMU Dr. YinFeng Xie and Dr. Yulong Ding-NFU

 Through industrial manufacturing, waste disposal, and human agricultural activities, plants have been exposed to excessive amounts of heavy metals, leading to toxic conditions.  Heavy metal pollution to water and soil poses a major environmental problem.

 Chromium is a natural component in soil, with a number of heavy metals, being required by plants as micronutrients.  Chromium concentrations in contaminated soils result in a decrease of plant growth and development, and negatively affects the plant’s photosynthesis.

 Heavy metals cannot be destroyed or degraded but are only transformed from one oxidation state to another.  Remediation of heavy metal contamination in soils is difficult.  Studies have shown of some methods used for the remediation of heavy metals in plants.  Thus, these methods has caused large destruction of soil structure and fertility, therefore new experimental phytoremediation strategies are necessary.

 Silicon plays a significant role in soil formation processes.  Silicon is a plant nutrition that reinforces the plant’s protection from diseases and containments.

 Malondialdehyde (MDA)  widely used marker of oxidative lipid injury whose concentration varies in response to biotic and abiotic stress.  MDA is the main product of membrane lipids when plants are subject to several stress levels.  Chlorophyll content  an index used to diagnose the plant nutrients’ status or damage of a plant.

 To test the oxidative damage of Indocalamus Barbatus McClure Bamboo species exposed to chromium (Cr).  To develop the potential Indocalamus Barbatus McClure Bamboo species for phytoremediation activity, Silicion (Si) was tested to restore the balance in the plant.

 The Indocalamus Barbatus McClure Bamboo species was planted by the Nanjing Forestry University graduate students last semester of September  The bamboo was planted in 1 kg of dry soil. The students observed and allowed the plants to grow for a time span of 60 days.

 Chromium Exposure:  Control = O g of Chromium (5 pots)  Experiment #1 = 200 g of Chromium (5 pots)  Experiment #2 = 400 g of Chromium (5 pots)  Experiment #3= 800 g of Chromium (5 pots)  The bamboo plants were watered twice daily with 150 mL of water.

 Silicon Exposure to 800 g of Chromium:  Control= O g  Experiment #1 = 100g of Silicon  Experiment #2 = 300 g of Silicon  Experiment #3 = 500 g of Silicon  The bamboo plants exposed to Silicon were watered twice daily with 150 mL of water.

 Sample Preparation: 1. Retrieve 0.2 g of Bamboo sample. 2. Grind sample using Quartz Sand and add 5mL 7.5% buffer solution. 3. Centrifuge sample for 15 minutes at 6,000 rpm using a Anke TGL-16G centrifuge. 4. Retrieve supernatant and use for various assays (i.e., MDA)

1. Measure 3 mL of tert-butyl alcohol (TBA) into a clean 15 mL test tube. 2. Add 2 mL of Bamboo sample to the test tube. 3. Heat the mixture for 15 minutes in a hot water bath at 100°C. 4. Centrifuge at 6,000 rpm for 15 minutes in Anke TGL-16G. 5. Place 2mL of the mixture into a cuvette and measure absorbance at 532nm, 450nm and 600nm using a 2802 UV/VIS Spectrophotometer, place 2mL of the mixture in a cuvette. The formula to calculate the data of MDA:

 To measure the chlorophyll content of the bamboo species, use a digital chlorophyll meter.

ControlExperiment g Experiment g Experiment g ± ± ± ± ControlExperiment g Experiment g Experiment g ± ± ± ± Table 1: The effect of chromium stress on MDA in bamboo. Table 2: The effect of silicon on MDA in bamboo exposed to 800 g of chromium.

Figure 1: Shows the increase in MDA content with exposure to 800 g of chromium which indicated damage, then shows the decrease in MDA content with the exposure of silicon, which indicate that it protected the bamboo from the oxidative damage caused from the exposure of 800 g chromium.

ControlExperiment g Experiment g Experiment g 1.47± ± ± ±0.01 Table 3: The effect of chromium stress on chlorophyll content in bamboo. ControlExperiment g Experiment g Experiment g 1.47± ± ± ±0.05 Table 4: The effect of silicon on chlorophyll content in bamboo exposed 800 g of chromium.

Figure 2: Shows the decrease in chlorophyll content with exposure to 800 g of chromium which indicated damage, then gradually shows increase in chlorophyll content with the exposure of silicon, which indicate that it protected the bamboo from the oxidative damage caused from the exposure of 800g of chromium.

BAMBOO EXCESS FROM CHROMIUM SILICON TO RELEASE THE DAMAGE FROM CHROMIUM

 The bamboo being exposed to chromium caused oxidative damage.  The bamboo exposed to silicon proved that silicon protected the bamboo against the oxidative damage caused by chromium exposure.

Jiang, Li, Gangrong Shi, Yulong Ding, Laiqing Lou, and Qingsheng Cai. "Differential Responses of Two Bamboo Species to Excess Copper." (n.d.): n. pag. Web. Jing, Yan-de, Zhen-li He, and Xiao-e Yang. "Role of Soil Rhizobacteria in Phytoremediation of Heavy Metal Contaminated Soils." C /. Journal of Zhejiang University, 8 Mar Web.

 Dr. Malinda Gilmore, AAMU Mentor and Academic Advisor  Dr. Yingfeng Xie and Dr. Yulong Ding, NFU Mentors  Graduate Students: Ghassem Emamverdiyan and Gao Yung  Dr. Zhen Wang  Dr. Elica Moss  Nanjing Forestry University  Alabama A&M University  National Science Foundation

我的文化体验 My Cultural Experience