The key difference between rhizosphere and phyllosphere is that rhizosphere is the region of soil surrounding the plant roots, which is under the influence of root exudates and associated microorganisms, while phyllosphere is the surface of the above-ground plant parts that provide habitat for the microorganisms.
Rhizosphere and phyllosphere are two regions associated with plants. The rhizosphere is the region of soil in the vicinity of plant roots. Moreover, it is under the influence of plant roots, their exudates and interacting microorganisms known as root microbiome. Phyllosphere is the total surfaces of a plant inhabited by microorganisms. Both rhizosphere and phyllosphere are beneficial for the plant. These two microenvironments fulfil different roles for the plant.
CONTENTS
1. Overview and Key Difference
2. What is Rhizosphere
3. What is Phyllosphere
4. Similarities Between Rhizosphere and Phyllosphere
5. Side by Side Comparison – Rhizosphere vs Phyllosphere in Tabular Form
6. Summary
What is Rhizosphere?
The rhizosphere is the zone of soil influenced by the presence of the plant roots. In this microenvironment, there is an important interaction between plant, soil and microfauna, which promotes plant growth. Rhizosphere microbial community varies from plant species to species based on the soil types. It mainly consists of plant growth-promoting rhizobacteria and mycorrhizae. Therefore, rhizosphere microorganisms should be the main focus to achieve success in nutrient management in soil.
Figure 01: Rhizosphere
Moreover, the rhizosphere of a plant differs chemically and physically from the bulk soil. Plant exudates are the main factors which influence the growth of rhizosphere colonizers. It is because plant exudates such as carbohydrates, amino acids and vitamins, etc. are specific to plant species, and they greatly influence the rhizosphere and its’ microbes. However, rhizospheric microorganisms are beneficial to plant. These microbes promote plant growth by increasing the soil nutrients that are accessible to plant. Moreover, they protect the plant from root pathogens. Furthermore, rhizospheric microbes participate in the production of plant growth hormones.
What is Phyllosphere?
Phyllosphere is the above-ground plant part surfaces that provide habitats for microorganisms. Generally, phyllosphere is a term that refers to the microorganisms inhabiting the leaf surfaces. But, in a deep sense, this term refers to the total above-ground surfaces of plants microorganisms inhabit. Hence, there are subdivisions of phyllosphere based on the plant part. They are caulosphere (stems), phylloplane (leaves), anthosphere (flowers), and carposphere (fruits). Phlyllosphere is mainly inhabited by bacteria, yeast, and fungi. Their adaptations to changing sunlight, temperature and moisture are high. However, the population densities of phyllospheric microbes differ with the age of the leaf. For example, higher populations can be seen near the meristematic tissues.
Figure 02: Plant Microbiome
Majority of the phyllospheric microorganisms do not show direct involvement with the plant growth and function. But, some are beneficial while some are pathogenic. Beneficial microbes enhance the plant growth by producing plant growth hormones and protecting the plant from pathogens. Furthermore, pathogenic microbes that are on the plant become a cause of food poisoning and transmission of plant diseases among plants.
What are the Similarities Between Rhizosphere and Phyllosphere?
- Rhizosphere and phyllosphere are two regions where plant and microbes interact with each other.
- Both regions are beneficial to plant since plant growth-promoting microorganisms inhabit them.
- Moreover, these regions promote plant growth by producing plant growth hormones and protecting plants against pathogens.
What is the Difference Between Rhizosphere and Phyllosphere?
Rhizosphere refers to the region of soil in the vicinity of plant roots. In this area, microbial activity is high. On the contrary, phyllosphere refers to the total above-ground surfaces of a plant, especially leaf surfaces that provide habitats for microorganisms. In this area, a majority of microbes do not involve with the plant growth and function. So, this is the key difference between rhizosphere and phyllosphere. Furthermore, root exudates influence the rhizosphere microbiome, while leaf exudates influence the phyllosphere microbiome. Therefore, this is also a difference between rhizosphere and phyllosphere.
The below infographic provides more details on the difference between rhizosphere and phyllosphere.
Summary – Rhizosphere vs Phyllosphere
The rhizosphere is the region of soil that surrounds plant roots. The microorganisms that inhabit this area are under the influence of plant root exudates. Moreover, most rhizospheric microorganisms are plant growth, promoting bacteria and mycorrhizae. They enhance plant growth. On the other hand, phyllosphere refers to the total above-ground surfaces of a plant inhabiting microorganisms or epiphytes. Phyllospheric microbes live under the influence of leaf exudates. So, this summarizes the difference between rhizosphere and phyllosphere. Both rhizosphere and phyllosphere microbes are beneficial for the plant. Moreover, they make nutrients available to plants, control pathogens, improve disease resistance, etc.
Reference:
1.“Phyllosphere – Soil Microbiology.” BrainKart, Available here.
2. “Phyllosphere.” Phyllosphere – an Overview | ScienceDirect Topics, Available here.
Image Courtesy:
1. “Rhizosphere composition” By Zebragurl4 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Plant microbiome” By Murali Gopal & Alka Gupta – Microbiome Selection Could Spur Next-Generation Plant Breeding Strategies, Front. Microbiol., 07 December 2016 (CC BY-SA 4.0) via Commons Wikimedia