 Next, we have Angus Ray from the Research School of Biology in the A New College of Science, and the title of Angus's three-minute thesis is Unraveling the Threads of Symbiotic Function. Plants need nitrogen to grow, and around 78% of the air is nitrogen gas, but it sucks to be a plant because they can't use nitrogen in its gaseous form, and it quickly runs out in the soil. So we use artificial nitrogen fertilizers that not only take a lot of energy to produce, but can also cause acid buildup in soils and spoil fresh water by runoff. We need a better source of nitrogen, and legumes may hold the key. Beans, peas, and other plants in the legume family form symbiosis, a mutually beneficial relationship with a special bacteria that lives inside their roots and converts the gaseous nitrogen into a usable form. If we can understand how this symbiosis has evolved in legumes and how it works, we should be able to make it happen in other plants and reduce our dependency on damaging fertilizers. My research is in how the bacteria enter legume roots, how they infect them in a good way. We know that the plant essentially swallows the bacteria by creating intestine-like tubes that pull them into the root. These microscopic tubes are called infection threads, and they're fundamental to this symbiosis, but we don't understand how they evolved or how they grow. I've developed methods in advanced microscopy so that I can delve inside cells and look closely at these tiny infection threads. What you're looking at is a unique combination of fluorescent cell wall dyes that I've used to stain infection threads and image them on a specialized light microscope. This beautiful cell is the result. The twisted pink tube inside the cell is an infection thread, and now that I've made a tool to study them in detail, I've learned how many there are per root and per cell, how long they typically are, and where in cells they usually originate. These are weird structures. They twist, they branch, and they merge. Though perhaps the most interesting thing that I've discovered is that around 10% of the time they grow backwards, and we don't yet know why, there's still so much to learn. The next step is to zoom in even further and work out the molecular signaling pathways that control the growth of infection threads so that we can potentially learn how to make them grow in other plants. This is part of the future of bioengineering our crops so that we can feed ourselves without wrecking the environment at the same time.