Phenotypic Plasticity in Green Algae
(2023) BIOM02 20231Degree Projects in Biology
- Abstract
- Understanding how organisms respond to their environment is essential in an increasingly fast changing world. For many organisms, phenotypic plasticity is the first response to environmental change. I investigated 1) if there are consistent differences in plastic response in three environmental gradients (Nitrogen/Phosphorus ratio, salinity and temperature) and 2) quantified the variation in reaction norm within 29 strains of green algae within genus Chlamydomonas. High-throughput methods were used to quantify population growth and four key ecological traits; Chlorophyll a (Chla), neutral lipids, reactive oxygen species (ROS) and starch. Five levels were used for each gradient. Using a Random Regression Mixed Model (RRMM) approach, we were... (More)
- Understanding how organisms respond to their environment is essential in an increasingly fast changing world. For many organisms, phenotypic plasticity is the first response to environmental change. I investigated 1) if there are consistent differences in plastic response in three environmental gradients (Nitrogen/Phosphorus ratio, salinity and temperature) and 2) quantified the variation in reaction norm within 29 strains of green algae within genus Chlamydomonas. High-throughput methods were used to quantify population growth and four key ecological traits; Chlorophyll a (Chla), neutral lipids, reactive oxygen species (ROS) and starch. Five levels were used for each gradient. Using a Random Regression Mixed Model (RRMM) approach, we were able to estimate non-linear reaction norms. Strains differed in all traits, and there were significant differences in plasticity for many traits. Variation between strains was consistently larger than the differences between high and low levels of each of the environmental treatments. Plasticity appeared to be most different from each other in salinity treatment for the traits Chla, lipids and ROS. The results suggest that there is substantial heritable variation for selection to act on. If these differences between strains are sustained in nature, it is expected that this Chlamydomonas population has a high ability to adapt in a changing environment. (Less)
- Popular Abstract
- The first response of algae to their environment
All living organisms are constantly interacting with the environment. When their environment changes – for example by getting hotter - organisms need to adjust their traits to stay alive. A more long-term solution is adaptation, but this requires sufficient heritable variation in how organisms cope with environmental stress within a population.
Our current world is changing at an increased speed because of the impact of human activity on the earth. Many organisms are struggling to keep up with this fast-paced change. The increased extinction of species has become a large problem resulting in the biodiversity crisis. Therefore, it is important to be able to estimate the possible... (More) - The first response of algae to their environment
All living organisms are constantly interacting with the environment. When their environment changes – for example by getting hotter - organisms need to adjust their traits to stay alive. A more long-term solution is adaptation, but this requires sufficient heritable variation in how organisms cope with environmental stress within a population.
Our current world is changing at an increased speed because of the impact of human activity on the earth. Many organisms are struggling to keep up with this fast-paced change. The increased extinction of species has become a large problem resulting in the biodiversity crisis. Therefore, it is important to be able to estimate the possible responses of organisms to this change. The first response of an organism can be behavioral, physiological or morphological. While on a longer time scale, genetic mutations can result in adaptations. For example, we search for shade on a hot day which is the first response to heat. Our ancestors lost all their body hair as an adaptation which improved their ability to cool down in the heat.
I tested the response of 29 strains of micro-green algae in three gradually changing environments that differed in temperature, salinity and nutrient availability. Since algae have clonal reproduction a strain can be considered as an individual. At five points over the gradient, four algal traits and population growth were measured. Population growth indicates how well the algae are still able to reproduce and the four traits give information on their stress level and metabolic functioning. By quantifying the effect of the environment along this gradient, common trends and differences between the strains could be visualized.
This experiment showed that strains responded differently to environmental stress. These responses differed in magnitude and direction. Therefore, there is no one way we can expect the green algae to respond to an environmental stressor.
Differences in individuals of a population are vital for a population to resist change. When a population exhibits high diversity there is more possibility for some individuals to possess advantageous traits. Consequently, these individuals will have a better chance to survive an environmental shift.
The high variation in the instant response of algae found in this study suggests that micro-green algae can rapidly adapt to a change in their environment. This is crucial since phytoplankton account for fixing nearly 50% of Earth’s annual CO2 and are the base of any aquatic ecosystem. Additionally, it also paves the way for research on the relationship between the instant response of an organism and their long-term survival.
Master’s Degree Project in Biology, 30 credits 2023
Department of Biology, Lund University
Advisor: Jana Isanta-Navarro and Tobias Uller
Advisors Unit; Evolutionary Ecology/Aquatic Ecology (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9135713
- author
- Hoogenboom, Ragna
- supervisor
- organization
- course
- BIOM02 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9135713
- date added to LUP
- 2023-08-30 16:01:40
- date last changed
- 2023-08-30 16:01:40
@misc{9135713,
abstract = {{Understanding how organisms respond to their environment is essential in an increasingly fast changing world. For many organisms, phenotypic plasticity is the first response to environmental change. I investigated 1) if there are consistent differences in plastic response in three environmental gradients (Nitrogen/Phosphorus ratio, salinity and temperature) and 2) quantified the variation in reaction norm within 29 strains of green algae within genus Chlamydomonas. High-throughput methods were used to quantify population growth and four key ecological traits; Chlorophyll a (Chla), neutral lipids, reactive oxygen species (ROS) and starch. Five levels were used for each gradient. Using a Random Regression Mixed Model (RRMM) approach, we were able to estimate non-linear reaction norms. Strains differed in all traits, and there were significant differences in plasticity for many traits. Variation between strains was consistently larger than the differences between high and low levels of each of the environmental treatments. Plasticity appeared to be most different from each other in salinity treatment for the traits Chla, lipids and ROS. The results suggest that there is substantial heritable variation for selection to act on. If these differences between strains are sustained in nature, it is expected that this Chlamydomonas population has a high ability to adapt in a changing environment.}},
author = {{Hoogenboom, Ragna}},
language = {{eng}},
note = {{Student Paper}},
title = {{Phenotypic Plasticity in Green Algae}},
year = {{2023}},
}