The rhizosphere is the area of soil that surrounds plant roots and is influenced by the presence of living plant roots. It is a dynamic region of the soil where plants interact with microorganisms, and it plays a crucial role in maintaining the health of the soil and the surrounding ecosystem. Plant growth-promoting rhizobacteria (PGPR) are a group of bacteria that live in the rhizosphere and provide benefits to plants (de la Fuente Cantó et al., 2020; Egamberdieva et al., 2015; Gupta et al., 2015; Pattnaik & Busi, 2019; Shi et al., 2015; Subrahmanyam et al., 2020).

This Blog will explore the connection between PGPR, ecosystems, and biodiversity, drawing on recent research and articles.

The Benefits of PGPR

PGPR are known for their ability to promote plant growth by several mechanisms, including nitrogen fixation, solubilization of phosphorus, production of plant growth hormones, and suppression of plant pathogens. These bacteria form a mutualistic relationship with plants, whereby they provide nutrients and growth factors to the plant, and in return, they receive a carbon source from the plant. PGPR can also improve soil structure, increase water-holding capacity, and enhance the bioavailability of nutrients to plants (Bhatt & Bhatt, 2021; Grover et al., 2021; Gupta et al., 2015; Kumar et al., 2015).

The use of PGPR as a natural alternative to chemical fertilizers has gained increasing attention in recent years due to their potential to improve crop yields, reduce fertilizer costs, and promote sustainable agriculture (Gouda et al., 2018; Kumari & Singh, 2020). Furthermore, the use of PGPR has the added benefit of reducing environmental pollution caused by the excessive use of chemical fertilizers (Arjumend et al., 2022; Guo et al., 2020).

PGPR and Ecosystems

The benefits of PGPR extend beyond individual plants to entire ecosystems. The microbial community in the soil plays a crucial role in maintaining soil health and fertility, and a diverse microbial community is important for ecosystem stability (Ju et al., 2019; Kumari et al., 2019; Moore et al., 2022).

Research has shown that the use of PGPR can increase the abundance and diversity of beneficial microorganisms in the soil, leading to improved soil health and increased biodiversity. For example, a study conducted by (Wang & Huang, 2021) found that the use of PGPR in rice paddies increased soil microbial diversity and altered the microbial community composition. The researchers concluded that the use of PGPR could promote the development of a more stable and diverse microbial community in the soil, which could lead to increased ecosystem resilience.

PGPR and Biodiversity

Biodiversity is a critical component of healthy ecosystems, and the use of PGPR can contribute to the maintenance and enhancement of biodiversity. The presence of PGPR in the rhizosphere can promote the growth of plants, which can provide habitat and food for a wide range of organisms. Furthermore, the use of PGPR can reduce the need for chemical fertilizers, which can have negative effects on biodiversity by reducing the abundance and diversity of soil organisms (Khanna et al., 2021; Miralles-Wilhelm, 2021; Zainuddin et al., 2022).

A study conducted by  (Lehman et al., 2015) investigated the effects of PGPR on the biodiversity of a grassland ecosystem. The researchers found that the use of PGPR increased plant diversity and biomass, which in turn led to an increase in the diversity and abundance of insects, spiders, and soil microorganisms. The study concluded that the use of PGPR could have significant positive effects on biodiversity in grassland ecosystems.

Challenges and limitations

Despite the potential benefits of PGPR, there are some challenges and limitations to their use. One of the major challenges is the complexity of the microbial community in the soil, which can make it difficult to predict the effects of PGPR on soil health and plant growth. Furthermore, the effectiveness of PGPR can be influenced by various factors, such as soil type, climate, and plant species, which can make it challenging to develop a one-size-fits-all approach to the use of PGPR (Alori et al., 2017; Fierer et al., 2021; Mokrani et al., 2022).

Another limitation of the use of PGPR is the lack of regulation and standardization in the production and application of PGPR products. This can lead to inconsistencies in the quality and efficacy of PGPR products, which can make it difficult for farmers and growers to determine the best product to use for their specific needs. In addition, the lack of regulation can also lead to the proliferation of ineffective or even harmful products on the market, which can have negative effects on soil health and plant growth (Kumar & Singh, 2015; Naveed et al., 2015; O'Callaghan et al., 2022).

Another challenge in the use of PGPR is the potential for unintended consequences. For example, the use of PGPR can alter the composition of the microbial community in the soil, which can have unintended effects on other organisms in the ecosystem. In addition, the use of PGPR can also lead to the development of resistant strains of bacteria, which can have negative effects on the long-term efficacy of PGPR products (Di Salvo et al., 2018; Khatoon et al., 2020).

Furthermore, the use of PGPR can also have limitations in terms of scalability and cost-effectiveness. While the use of PGPR can be a sustainable and cost-effective alternative to chemical fertilizers, the production and application of PGPR products can be expensive and labor-intensive, which can make it difficult for small-scale farmers to adopt this approach (Mohan et al., 2021; Zvinavashe, 2022).


In conclusion, the rhizosphere is a dynamic region of the soil where plant-microbe interactions play a crucial role in maintaining the health of the soil and the surrounding ecosystem. PGPR are a group of bacteria that provide benefits to plants by promoting plant growth and improving soil health. The use of PGPR can also have positive effects on ecosystem stability and biodiversity. However, there are also challenges and limitations to the use of PGPR, including the complexity of the microbial community in the soil, the lack of regulation and standardization in the production and application of PGPR products, and the potential for unintended consequences. Despite these challenges, the use of PGPR has the potential to promote sustainable agriculture and contribute to the maintenance and enhancement of biodiversity.


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About the Authors: Qudrat Ullah and Etisam Mazhar are the MPhil scholars of Environmental Sciences at Government College University Faisalabad, Pakistan.