The roots release a series of exudates into the rhizosphere. These root exudates act as an “intermediary” between plants and the soil to alter the growth environment of the roots. This process not only facilitates the absorption of nutrients by plants but also enables the modulation of the structure of the microbial community.
In adaption to iron deficiency, Poaceae crops have evolved a unique mechanism, the specific secretion of phytosiderophores. 2’-Deoxymugineic acid (DMA) is a common phytosiderophore with ability to activate the insoluble iron in the soil. Subsequently, DMA-iron complexes can be absorbed by plants, such as maize and peanut, ensuring the normal growth of plants in an iron-deficient environment. However, due to its instability and high production costs, DMA is applied with major limitations.
READ MORE: Under the microscope: the rhizosphere
READ MORE: Fertilizer strategies can shape microbial communities in the rhizosphere
In recent years, researchers have successfully synthesized a DMA analog, proline-2’-deoxymugineic acid (PDMA). PDMA overcomes the problems of DMA while retaining the important advantage of DMA in activating soil nutrients. Therefore, PDMA is suitable to explore the response of the rhizosphere microbe under the influence of phytosiderophores. This research will provide theoretical support for improving the efficiency of plant nutrient absorption in agricultural production.
Rhizosphere community
In this study, Professor Yuanmei Zuo found that PDMA had a significant impact on the composition of the rhizosphere microbial community. Under the application of PDMA, Actinobacteria in the peanut rhizosphere were significantly enriched at the phylum level. At the genus level, among the 11 enriched genera, 6 belonged to Actinobacteria.
Further correlation analysis results showed that the relative abundances of Actinobacteria and many genera at the genus level in the peanut rhizosphere had a significant positive correlation with the bioavailability of nutrients in plants and soil. In particular, Cellulosimicrobium and Marmoricola may be closely related to the activation of iron and zinc in the rhizosphere.
From the network analysis, the application of PDMA led to a highly interconnected state among the nodes in the microbial network, with a tightly connected internal network structure. Meanwhile, PDMA significantly enhanced environmental information processing, cellular processes, and genetic information processing of rhizobacteria. The results of the secondary pathway analysis indicated that PDMA also enhanced the biodegradation and metabolism of exogenous substances, signal transduction, cellular processes, and membrane transport of rhizobacteria.
Tight and stable network
This study elucidated that PDMA forms a tight and stable microbial network in the rhizosphere and promotes mutual communication among microorganisms.
It reveals that PDMA mediates the dynamic association between plants and beneficial rhizobacteria, demonstrating great potential as a novel functional fertilizer.
This research was published on the Journal of Frontiers of Agricultural Science and Engineering in 2025, 12(1): 69–80. DOI: 10.15302/J-FASE-2023531.
No comments yet