Plant Reproduction with the McLetchie Lab - Podcast Transcript


Have you ever wondered who was doing the research that will impact your future? The research podcast lets you met those people, and learn how the University of Kentucky is exploring and strengthening our understanding of the world through research and discovery.   


Here's Alicia Gregory, director of Research Communications. 


Alicia: Today we’ll meet Nicholas McLetchie and two PhD students who work with him: Jonathan Moore and Rose Marks. We met up with them in a greenhouse on campus to talk about their work on plant reproduction.


Nicholas McLetchie: My name is Nicholas McLetchie. I'm in the Department of Biology at the University of Kentucky. 


My goals are to understand how the sex ratio of plants differ, or why they differ. So I'm interested in the number of males, and the number of females, in plant populations. And, we use several techniques to do that. Including field experiments, field observations, greenhouse studies, growth chambers, where we manipulate the environment and try to look for differences between males and females.


Nicholas McLetchie: I'm hoping to learn how males and females are different. Even though they are different, how they can persist close to each other so they can actually mate and reproduce. It's basically understanding the differences in terms of life history, how fast they grow, when they start producing reproductive organs, and when they actually mate, and how successful they are.


One of the things we've figured out, is we can make both males and females reproduce within 21 days. We really don't understand the mechanism, but we can manipulate the environment, and we can cause males and females to become reproductive [snaps] like that. That is nice. 


Nicholas McLetchie: For me, I had two choices as a high school student. Either art or understanding or protecting tropical forests. I was good at art, but I was worried about making a living. And, I liked to be in a forest. It was really something very early on, where an appreciation of plants was part of my being. If you want to put it that way.


What keeps me going? Is the fact that every time I see a plant, and I look at it, and I think I understand it, and I'm getting closer to understanding, it does something that tells me that it knows more about what it's doing than I do. And, then I have to start back from the beginning, and try to understand again why the plant is behaving the way it does. With the ability to sex express, I can make it happen. But, it's very difficult for me to figure out the mechanism, because everything people tell me about what should trigger it, the plant is responding a bit differently. So, I'm at a loss. What makes me keep on being excited about it, is the mystery and the questions I keep coming to.


Nicholas McLetchie: When I came to UK, I was given a certain number of resources, if you like, and the flexibility to actually ask questions that I'm interested in. It provides an environment where I can do what I want to do. The students are also talented. And, I get really good undergraduate students to work with me. And, without the undergrads, my lab cannot function. It's a smart bunch of students. And, then we have really good grad students too. It's the place, the resources, the ability to do the research that I want to do. And also the students.


Jonathan Moore: I'm Jonathan Moore. I work with Dr. McLetchie. 


I love science. I love generating new knowledge. And, I love living organisms. So, biology was a natural fit. And I wanted to find a way to learn new things about the natural world, and I love, specifically, plants. I love growing things, so those things came together. 


Jonathan Moore: Right now, I am working on explaining sex ratios and differences in the sexes. What I look at specifically, is trying to explain differences between the sexes. Looking at their morphologies, their physiology, and their life history traits; and connecting those back to selection for being a good male or a good female.


So, that has implications for their sex-ratio dynamics, the population dynamics. I'm also looking at how that affects their abilities to reproduce. So, a lot of their traits are geared towards sexual reproduction, and there are consequences on what makes a good male, what makes a good female, on the differences between the two sexes. 


Jonathan Moore:  So, I work with a moss, and it has -- they're a little clump forming moss. The males and females differ in how their clumps are formed, and they're kind of the shape that they are. Females are bigger than males, they have different morphologies in their shoots, and they hold different amounts of water. So, that's really important for their reproduction and their regular lifecycle. So, looks as though females are probably more competitive than males, but it's also linked to what makes them a good male or a good female. Females need to get water, because they're water fertilized, and males need to lose water to disperse their gametes to the females. So, they may have-- what makes them a good male may also make it more likely that they might die. 


What I like the most is actually the people that I interact with. So, I love my lab mates, and I love my advisor. And, I think that their influence has been a really good one for learning how to do research, and learning how the scientific process works, and collaborating with each other. And, basically learning how to do science together.


Rose Marks: I'm Rose Marks, and I work in Dr. McLetchie's lab. 


I've always been really interested in the natural world, and being outdoors, and have had a passion for plants. And, I worked in agriculture, on organic farms, for four or five years and so, going into plant science and biology was a natural choice for me once I decided I didn't want to break my back on a farm anymore. 


Rose Marks: So, my project, my dissertation project, is about understanding how some plants can survive without water. Which seems like a relevant issue, considering there's a lot of drought world-wide. And, so, we're looking at sort of the ecology of plants that are drought or desiccation tolerant, as well as the molecular mechanisms. So, trying to understand what genes actually allow them to survive without water. 


I've done a side project, which is looking at all of the bacteria that colonize these plants. And, what we've found, was that there's a lot of nitrogen fixing bacteria that are associated with these plants. And, typically, people think about nitrogen fixing bacteria only being with legumes, so beans and peas, but we're finding that it's actually associated with a much broader range of plants. Including these little bryophytes. And, so that was really exciting to find out. 


Rose Marks: It could mean that bacterial nitrogen fixation is more common than we thought. And, that maybe plants can't even survive without the bacteria, and so there's this whole other group of organisms that have gone unnoticed for years, but are really playing an important role. 


It’s very interesting, and as a career, you're always sort of doing something different, so you don’t have to worry about the nine to five grind. And if you're interested in the natural world and understanding how living creatures work, then it’s a great choice.


Rose Marks: Working with Dr. McLetchie is probably the highlight. That's been a really great fit for me. And, also living in Kentucky has been really fun. So, I grew up in New Hampshire, and then lived in Montana. And, I've always been in these very cold climates, and so it's been a real joy to be somewhere warmer. And, the vegetation and the plant life here is just gorgeous. And, so, when you're studying plants, it's very inspiring to be around so much green all the time. 


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