Beneficial Interactions between Legumes & Rhizobium: Plant Survival Tips

Exploration of Beneficial Species Interactions between Legumes & Rhizobium What does a plant need to survive & thrive?

Discuss with your group. 1) What do you think will grow from these seeds? 2) How are the grass and clover seeds similar and different?

1st Think, Pair, Share On your own think about the answer to the following question: 1) What does a plant need to grow? Pair with one other person & discuss your answers to the questions. Be ready to share with the class at the end of the 1 minute. Share your ideas with the class. We will record all the initial ideas on a large sheet of paper to look at during this lesson to help us revise our original ideas.

2nd Think, Pair, Share On your own think about the answer to the following question: 1) What does a plant need to thrive & survive? What makes some plants grow better than others? Pair with one other person & discuss your answers to the questions. Be ready to share with the class at the end of the 1 minute. Share your ideas with the class. We will record all the initial ideas on a large sheet of paper to look at during this lesson to help us revise our original ideas.

Legume & Rhizobium Experiment 1. 2. As a group read the procedure & answer the pre-lab questions 3. After reading both the introduction & procedure discuss these questions with your group: As a class we will read the introduction What is bacteria? How will the bacteria affect the plants? Is bacteria good or bad? What does bacteria do? 1. After discussing these questions, write down your four hypotheses before we begin the experiment.

Materials Planting demonstration - see how I use the materials to plant the seeds. After I complete the demonstration, each group will label their containers so we are ready to plant.

What do you expect to see when we harvest the plants?

Initial Hypothesis Review your hypotheses. What what did you think the grass would look like above and below the soil? What what did you think the clover would look like above and below the soil? Share with your group: Why did you make these hypotheses?

Plant Observation Log The plants should be checked on daily. Record the qualitative (describing details) data you observe and quantitative (measured) data for each set of plants. Example: Date + (rhizobium) - (no rhizobium) Water (y/n) 8 seeds were planted, they are sitting on top of the soil. The soil is a light brown and no plants are visible. 10 seeds were planted, they are sitting on top of the soil. The soil is a light brown and no plants are visible. 5/12/23 Y 5 of the 8 seeds have started growing. The plants are bright green in color. The sprouts average a height of 2 cm. 10 of the seeds have started growing. The plants are not as bright of a green as the + group. The sprouts average a height of 3 cm. 5/17/23 N

Harvesting the Plants Video (Procedure is on the handout) Harvesting Legume and Grass Roots

Rhizobia Nodules - What you are looking for. Some nodules may even be red, this is from their hemoglobin. These are what is used to give meat alternatives, like Beyond Beef, its red color.

Harvesting the Plants Important reminders: 1. Be very gentle with the roots 1. Do NOT put any soil down the sink. All soil that needs to be washed off should be done over a tray to prevent the soil from going down the drain.

Plant Harvest Data Collection On your worksheet you will take observations, both qualitative and quantitative. A drawing of what you see is also required. This can be the entire plant and a zoomed in section if you see something that look interesting or you feel should be documented. After your group has completed the observations & drawing: 1) Find a group that has completed their observations and drawings 2) Observe their plant and ask them about their observations 3) Then compare your observations. What was similar or different?

What are those bumps on the clover roots? The bumps you may have seen on the roots of the clover plants are called nodules. The clover used in this experiment were legumes. Legumes include lentils, peas, beans, and clover. The seeds we used were inoculated (coated) with a special rhibozome bacteria that survives well on clover plants. These bacteria which are a key mutalist for legumes, which means both the clover and the bacteria benefit from living with each other. The rhibozome bacteria fix nitrogen for the plant, and in turn the plant makes nodules, or small homes for the rhizobia on the plant roots. The plant trades rhizobia carbon that the plant takes in from photosythesis, which in turn helps rhizobia grow.

Legumes with Professor Ray Weil: Root Nodules An examination and discussion with Professor Ray Weil of clover root structure, nodules, and the symbiotic relationship legume roots can form with bacteria. Source: https://www.youtube.com/watch?v=9xcgEC2ZO14

Show What You Know Using what you have learned during this unit about the nitrogen cycle, make a claim about why the plants that grew best may have done better than others. What evidence do you have to support this claim?