Bacterial and Fungal Communities Are Differentially Modified by Melatonin in Agricultural Soils Under Abiotic Stress

Abstract

An extensive body of evidence from the last decade has indicated that melatonin enhances plant resistance to a range of biotic and abiotic stressors. This has led to an interest in the application of melatonin in agriculture to reduce negative physiological effects from environmental stresses that affect yield and crop quality. However, there are no reports regarding the effects of melatonin on soil microbial communities under abiotic stress, despite the importance of microbes for plant root health and function. Three agricultural soils associated with different land usage histories (pasture, canola or wheat) were placed under abiotic stress by cadmium (100 or 280 mg kg−1 soil) or salt (4 or 7 g kg−1 soil) and treated with melatonin (0.2 and 4 mg kg−1 soil). Automated Ribosomal Intergenic Spacer Analysis (ARISA) was used to generate Operational Taxonomic Units (OTU) for microbial community analysis in each soil. Significant differences in richness (α diversity) and community structures (β diversity) were observed between bacterial and fungal assemblages across all three soils, demonstrating the effect of melatonin on soil microbial communities under abiotic stress. The analysis also indicated that the microbial response to melatonin is governed by the type of soil and history. The effects of melatonin on soil microbes need to be regarded in potential future agricultural applications.

Phytomelatonin in stress management in agriculture

“…Besides, as a potential synergist, melatonin can also possibly lessen the utilization of substance fungicides. It is reported to enhance substance fungicides effectiveness, limit the use of synthetic fungicides, and further diminish their requirements for crop protection ( Madigan et al, 2019 ; Zhang et al, 2017 ).…”

Unraveling Techniques for Plant Microbiome Structure Analysis

“…Terminal restriction fragment length polymorphism (T-RFLP) follows the same rule could be used to evaluate spatial and temporal deviations in microbial community [32]. One of the most powerful techniques with high resolution and reproducibility for detecting the fungal diversity was automated ribosomal intergenic spacer analysis (ARISA) [69,70]. Ribosomal intergenic spacer analysis (RISA) is related to the length of the ribosomal intergenic spacer region between the 16S and 23S rRNA genes [71,72].…”

A Systematic Review of Melatonin in Plants: An Example of Evolution of Literature

“…With a growing global population, decreasing amounts of land which are traditionally suitable for agricultural cultivation, and increasing climactic uncertainty with global climate change, melatonin represents a potentially invaluable means by which to maintain or enhance agricultural production under less favorable growing conditions. The emphasis on melatonin mediated stress responses in agricultural species to date has created an interesting niche which has yet to be explored, including the potential implications of melatonin application on soil microbiomes and persistence which will be an important consideration (Madigan et al, 2019). These same factors which are having dramatic impacts on agricultural species are also impacting wild and native species around the word.…”