Evaluating the Potential of Fluoride-Resistant Fungi as Plant Growth Promoters in Rhizosphere Soil from Madhya Pradesh and Rajasthan

Ritu Kanthiya¹, Rakesh Kumar Verma^1*, Deepak Bharti²and Saloni Kanthiya³

¹Department of Bioscience , Mody University of Science & technology Lakshmangarh, sikar, Rajasthan,India

² Department of Molecular biology, CMBR Biotech Pvt Ltd, Bhopal MP, India

³Department of Horticulture (Vegetable Science), ITM University Gwalior M.P., India

Corresponding Author:  mail ID: rkverma.slas@modyuniversity.ac.in

Abstract:

This study aimed to assess the plant growth-promoting abilities of selected fluoride-resistant fungi isolated from rhizosphere soil samples in fluoride-impacted regions of Bhopal District Madhya Pradesh and Sikar District Rajasthan, India. The fungi evaluated included Aspergillus niger, Trichoderma harzianum, Aspergillus flavus, Penicillium chrysogenum, Cladosporium cladosporioides, and Aspergillus tamarii. We also examined IAA bioactivity, ammonia production, phosphate dissolving power, HCN production, and siderophore production. As positioning of the crops was found to vary with the addition of the fungi, it was also found that both Aspergillus niger and Trichoderma harzianum were the most effective in boosting plant growth metrics. This ability to synthesize the hormone IAA was also found to vary with the ‘A. niger’ strain being the most consistent with elevated synthesis levels even in the presence of fluoride, indicating its potential to enhance plant stress tolerance. Likewise, the ammonia production assay confirmed the results obtained through the previous test, further establishing ‘A. niger’ as an efficient donor of nitrogen, which was even further confirmed through the phosphate solubilizing assays. The assessments conducted for HCN production expanded the potential of the fungi as biocontrol agents, which was already attributed to their siderophores production as well as nutrient uptake mechanisms. This study underscores the important role of endophytic plant growth-promoting fungi (PGPF) that can thrive in fluoride-rich environments, helping to protect plants from fluoride-induced damage. By integrating these findings into sustainable agricultural practices such as bioaugmentation, organic amendments, and the cultivation of fluoride-resistant plant species the research lays the groundwork for biological strategies aimed at alleviating the negative effects of fluoride. The ultimate goal is to enhance agricultural productivity and improve soil health in areas impacted by fluoride contamination.

Keywords:

Ammonia Production; Fluoride-Resistant Fungi; HCN - Hydrogen Cyanide; IAA - Indole-3-Acetic Acid;  Phosphate Solubilization; PGPR - Plant Growth-Promoting Fungi; Siderophores

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