Analysis of Arabidopsis thaliana Growth Behavior in Different Light Qualities

The overall goal of this visual and molecular phenotype analysis is to compare plant growth under different light conditions and of various genotypes. This method can help answer key questions in the plant research field such as acclimation to different light conditions. The main advantage of this technique is that it gives reproducible and quantifiable results.

Demonstrating the procedure will be Franka Seiler, a technician in my laboratory. To begin, calculate an appropriate sample size and prepare the requisite number of six by seven centimeter pots with soil and plant a single seed in each. Then, vernalize the seeds at four degrees Celsius for two days.

Set the relative air humidity of a climatic chamber to 65%and the temperature to 22 and 16 degrees Celsius for a 16 hour day, eight hour night cycle. Then adjust the light on all levels to an intensity of 200 micromoles per square centimeter and second. Use the built in spectrometer to continuously monitor spectral output.

Place the plants in the climatic chamber, and cover them with a transparent top, until well developed cotalinins emerge. Visually inspect the plants, and record growth data photographically at regular intervals. To ensure consistent images, use a camera tripod and a scale bar for each picture.

First, place a plant in the dark for a few minutes. Then set up a pulse-modulated fluorometer and a camera at an appropriate distance from the plant. The complete rosette should be visible in the live window.

Start the software, and select the mini option that appears in the select unit window. Then, click okay. Next, select blue in the popup window, and click okay.

Select the live video option, and turn the adjustment ring of the objective lens to focus the image, and select a specific region of the plant. To exit the live window, click the exit box in the upper right hand corner. Define an area on interest, or AOI, with the default settings.

A circle and a red box with the average FT value of the pixels contained in the AOI, will automatically appear in the middle of the screen. You need to delete this AOI, before defining your own. Then accept the default settings in the tab at the right.

Next click add in the AOI tab, and place the circle within the leaf area. Repeat this process five times per leaf, selecting several leaves per plant. Tick the relevant box, with the maximal PS 2 quantum yield, to select the the FV/FM image.

Apply a saturating light flash to measure the photosynthetic parameters, via fluorescent clenching analysis, by pressing the F0, FM button. Locate the results in the report tab. Check all of the relevant boxes, and export them to appropriate analysis software.

In this study, LED lights were used to provide to provide stable light quantity and quality in the observation and analysis of plant growth and vena types. Data from the plants was collected at 12, 21 and 28 days after sewing. The mean effecting PS 2 quantum yield values of 5 plants and 5 are shown in this figure.

Data from plants grown under simulated sunlight, enriched blue or red light were statistically evaluated. This figure shows the mean effecting PS 2 quantum yield values of 5 plants and 5 per day. Mean values for plants grown under blue and red light was significantly higher than those grown under simulated sunlight.

Once installed, the LED lights can provide stable or variable light conditions by saving a lot of energy compared to fluorescent lamps. During the experiment, it is important to take on the plants daily. After it's development, this technique pave the way for researchers in the field of plant research to explore growth behavior of under different light conditions with defined wave length.

After watching this video, you should have a good understanding of how to grow, and analyze plants regarding their visual and molecular vena type in a quantitative manner.