Category: Winnie Zhao

During this research process, I have learned how different it is from doing research and experiments around a classroom setting. This was the first time I was doing my own research project with help from my research advisor. Usually, I have help from my classmates as well as instruction from the lab guide to assist me with my project. However, this time, I was in charge of everything from how I was going to set up my experiment to how I will record the data to the type of materials and equipment I would need and later how I will analyze my data. There were definitely a lot of unknowns that I had to deal with on my own as well as through communication with my advisor. We were both unsure about many things during this research process and we slowly figured it out through trial and error like how to best grow Japanese stiltgrass and how to make recordings of its movement. We adapted some ideas from existing literature and experiments and we discovered some small insights that were never mentioned or studied before. Like the TedTalk I have watched on the research process, it is not a straight line from A to B, where A is the starting point of the project development and B is the ending or the results from the project. There is actually a lot of variables that bring many twists and turns before finding your way back to B and the results might not be what you expected. 

 

From my research, I made a few interesting preliminary findings. Due to the COVID-19 outbreak and limited time, I was unable to repeat my experiments to confirm these findings. However, from the experiments that I was able to conduct, I noticed that Japanese stiltgrass grows better in 16-hour light compared to 24-hour light, as mentioned previously. Japanstiltgrass is healthier and more robust with greener leaves in 16-hour light while in 24-hour light the leaves turn yellow earlier and its stems are thinner. And from the data I collected of Japanese stiltgrass growing in 16-hour light, I got measurements of its root growth. I found a positive correlation between root length and the rate of root growth. As the root gets longer, the root grows at a faster rate. I created a graph displaying this data and it is shown below. 

Figure 1: The effect of Japanese stiltgrass root length on its root growth. 

Additionally, I found that Japanese stiltgrass has a tendency to fall over on its sides and it happens more than once. I originally thought it only falls over once through its growth but after review of my time-lapse videos, I noticed that it falls over multiple times. I do not have enough data to determine the causes that result in the plant to fall over but some possible factors could be to sense other plants nearby, to block other plants from growing in that area, or to take over territory so it can grow both laterally and vertically. Lastly, in my competition studies with Japanese stiltgrass and other plant species: Arabidopsis thaliana, Bachelor’s Button, Cosmos, and Zinnia, I noticed that there were ways in which these other plants were “fighting” with Japanese stiltgrass. The Zinnia grew taller with its leaves fanned out like a tree so Japanese stiltgrass grew a taller stem and grew under the shadows of Zinnia in lower light conditions but there were a few Japanese stiltgrass plants that bent itself to get access to better lighting. For the Bachelor’s Button and Cosmos, they also tried to keep Japanese stiltgrass from growing by growing above Japanese stiltgrass and using its leaves and stems to push down on Japanese stiltgrass or to cover the leaves of Japanese stiltgrass. As for Arabidopsis, it uses its agility and its fast growth rate to move into areas with Japanese stiltgrass to take up space and light resources. There was also one instance where I captured Arabidopsis wrapping itself around the Japanese stiltgrass in my time-lapse video. (This is the link to the video: https://drive.google.com/open?id=18O2Iuo1OlCMAIzJB6KCwOjfJ5UeuCeDs.)

So far for my project, I am about halfway through completing it. I have gone through three to four trials of preliminary research. After speaking with my advisor about my work, we determined that we are narrowing in on how to collect the data I am looking for with more controlled environments. My past experiments gave me insights on the kind of environment, particularly light conditions, where my plants grow well. I discovered that Japanese stiltgrass grows best in 16 hour light with 8 hours of dark because it has greener leaves and grows bigger while in 24 hour light, it looks weaker, less robust, and the leaves start yellowing at an earlier stage. 

This past Saturday, I had the opportunity to share my current findings from my research at the 39th Annual Dyson Society of Fellows meeting. At this meeting, I presented my findings on the conditions that Japanese stiltgrass grows the best in as well as some unexpected results I saw through my time-lapsed videos. Because Japanese stiltgrass is an invasive species, I expected it to take over the space where it is grown and all the other plants will succumb to it. However, I noticed that Japanese stiltgrass is actually the plant that pops up after all the other plant species germinated. And rather than succumbing to Japanese stiltgrass, the other plant species are actually keeping it in check and they are fighting a fair battle. The other plants use their leaves to push Japanese stiltgrass down and cover their leaves. In one video, Arabidopsis can be seen swinging its stem toward Japanese stiltgrass and sort of wrap itself around it. 

From the overall process of doing research, I realized that most of the time, there is no direct route in conducting research. I learned from my own experience and from talking to my advisor that when we do research, we do not really know what we will find. That is the beauty of doing research, but at times, it is also frustrating. The unknown of what I am looking for and what I will find is both exciting and frustrating. Through this process, I got a taste of what it is like to conduct academic lab research. In the beginning, it was just getting my feet wet, trying out the different possibilities and when I get some significant results or data, I can narrow in to find more data that supports a particular hypothesis.

When I first started my project, I did not know, specifically, how I wanted to study Japanese stiltgrass using time-lapse. There were a few ideas from discussions with my faculty mentor, Dr. Eric Brenner. They involved either studying the growth of Japanese stiltgrass and using time-lapse to record its growth or doing a competition study between Japanese stiltgrass and another species, like Arabidopsis thaliana, to observe the invasiveness of Japanese stiltgrass. After looking back at the data I already collected on the growth of Japanese stiltgrass and talking to Dr. Brenner, I decided to study the roots that grow from the stolons, or runners, of Japanese stiltgrass. Stolons are the horizontal stems of a plant and they have roots coming out of them to allow for the growth of another plant. I first noticed the roots of the stolons from my past experience of growing Japanese stiltgrass. Later, I hypothesized that the stolons play a role in keeping the plant upright as well as helping it “crawl” and “creep” its way into other territories. I recorded time-lapse movies of the stolon’s growth and its roots and realized that I have to record them at the appropriate stage in its life cycle when there is rapid growth. 

For my project so far, I have done trial runs experimenting with how I should conduct my experiment. At first, I was interested in growing Japanese stiltgrass together and record them using the time-lapse app, Lapse-It. However, through my recording process, I found it difficult to get clear recordings with good enough resolution of the plants to collect high-quality data. One drawback was that I was growing the plants in 16 hour light instead of 24 hour light, which meant that there were periods of dark in my recordings. That made it hard to track my plants because they are in the dark. Another obstacle I encountered when creating my time-lapse movies was that the plants were growing too densely together. After a certain stage, the plants grew so big that it was hard for the camera to distinguish each individual plant. The overlap of the stems and leaves of each individual made it hard to keep track of their movement over time. Therefore, I had to come up with a new method of growing and recording them. I decided to grow my plants in 24 hour light and record them in a different lab space. I currently have some data but I would need to grow more plants and repeat my experiment to get more accurate data. 

I communicated with my mentor, Dr. Brenner, by meeting up with him once every week to talk about my ideas for the project, data that I have collected, new tools that I might need, and the direction of my project. Dr. Brenner gave me enough support to help me move in the right direction but he also allowed me to take ownership of my project and pushed me to come up with ideas on what I wanted to do and how I wanted to do it.

The image on the top shows how the plant leaned over (from the right to the left) and grew a root from the stolon to station itself in the adjacent pot. The image on the bottom shows a closer view of the root that grew from the stolon, marked by the arrow on both images.

For my research project, I will be working with the plant known commonly as Japanese stiltgrass, or Microstegium vimineum. I chose to study this plant because it is an invasive species from Asia found in multiple states in the United State and is threatening the understory of forest edges as well as inside forests. The working title of my research is the “Characterization and determination of the aggressive growth patterns of Japanese Stiltgrass, Microstegium vimineum, using quantifiable time-lapse photography methodology.” I want to study the invasive nature of Japanese stiltgrass in the laboratory to understand and observe how invasive it is and to record the invasion using time-lapse photography. I want to use time-lapse photography to quantify how fast Japanese stiltgrass grows as well as how long it takes for it to outcompete another species. For my experiments, I will be using Arabidopsis thaliana, wildtype-Columbia as the “native” species to observe how Japanese stiltgrass invades the space of another species.

The objective of this project is to better understand the growth and development of Japanese stiltgrass and to examine the behavioral aspect, or the movement, of Japanese stiltgrass during invasion. To achieve the objective, I will grow Japanese stiltgrass in the lab to determine at what developmental stage and with what mechanism Japanese stiltgrass uses to hamper, strangle, and choke out the growth of native plants. This will be done by performing time-lapse competition studies and using the new App, Plant Tracer, to quantify and compare the growth rate of Japanese stiltgrass vs. target species (native species). This project will take another step toward managing Japanese stiltgrass and other invasive species. It will help scientists and conservationists understand the impacts (the good and the bad) that Japanese stiltgrass has on the environment and the “behavior” of the invasive grass to better learn how to properly manage it.