Molecular Soil Biology 2026, Vol.17, No.1, 26-37 http://bioscipublisher.com/index.php/msb 29 synergistic enhancement type, which indirectly enhances plant phosphorus uptake by producing iron carriers, altering root carbon flow, or interacting with mycorrhizae, etc. Due to the fact that "the same function is shared by multiple phyla and genera", the phosphate-solubilizing function at the community level may show certain redundancy. However, whether this redundancy is sufficient to resist stress in a strongly acidic and aluminum-rich environment still needs empirical evidence (Lang et al., 2022). 3.2 Community structure characteristics based on high-throughput sequencing High-throughput sequencing has facilitated the detailed characterization of microbial communities in tea plant root zones and soil: 16S rRNA and ITS amplicons can elucidate the bacterial/fungal community structure, while functional marker genes (such as phoD) can further focus on bacterial subgroups related to organic phosphorus mineralization. Studies on tea soil as the object indicate that the composition, abundance, and network structure of the phoD carrying community can significantly differ under different acidification levels, and are correlated with soil phosphorus components and tea yield and quality indicators (Rothenberg et al., 2022). On the other hand, short-term pot experiments with phosphorus supply also show that different phosphorus input levels can significantly alter the diversity of bacterial and fungal communities in the tea root zone, accompanied by differences in functional prediction pathways (such as carbon metabolism and phosphorus transport-related pathways), suggesting a traceable response chain between "management measures-root community-functional potential" (Lang et al., 2021; Li et al., 2024). 3.3 Mechanism of community assembly under acidic environments At multiple environmental scales, soil pH has been repeatedly demonstrated to be a key factor in explaining the diversity and composition differences of bacterial communities: classical continental-scale studies have shown that bacterial diversity and richness can be significantly explained by soil pH, and acidic soils typically have lower diversity (Kui et al., 2021). Returning to the tea garden system, acidification not only directly alters the physiological and resource acquisition strategies of bacteria, but also indirectly shapes ecological niches by changing Al activity, phosphorus forms, and the rate of organic matter decomposition, thereby enhancing the role of environmental selection (deterministic process) in community assembly (Rothenberg et al., 2022; Nian et al., 2025). In the case of tea garden soil acidification, the phoD carrying community diversity decreases and is accompanied by changes in the relative abundance of specific taxa, as well as differences in the complexity of the co-occurrence network, all of which support the mechanism framework of "acidification driving community reorganization and functional shift". 4 Functional Mechanisms of Phosphate-Solubilizing Bacteria (Psb): Recent Evidence-based Overview 4.1 Mechanism of organic acid secretion and inorganic phosphorus dissolution The core of inorganic phosphorus dissolution lies in "acidification + complexation": Phosphorus-depleting bacteria secrete organic acids such as gluconic acid and citric acid, which can lower the local pH, and simultaneously form carboxylate ligands to complex metal cations such as Ca, Fe, and Al, weakening the lattice stability of phosphate minerals and promoting the release of phosphorus (Leite et al., 2024). At the molecular level, the typical pathway is the periplasmic type PQQ-dependent glucose dehydrogenase (GDH) that oxidizes glucose to form gluconic acid, thereby achieving acidification of the medium and phosphorus dissolution; this process is closely related to the gcd and pqq gene clusters and can be regulated by environmental conditions such as soluble phosphorus levels (Chen et al., 2024). For acidic tea gardens, this mechanism may either promote phosphorus release or compete with processes such as aluminum chelation-re-precipitation, and the key to determining its net effect lies in the rhizosphere microenvironment and mineral components. 4.2 Analysis of phosphatase-related functional genes (such as phoD, gcd, etc.) PhoD is often used as a molecular marker for the potential of soil organic phosphorus mineralization: Relevant studies have pointed out through genomic and metagenomic database analysis that phoD is distributed across multiple bacterial phyla and is ubiquitous in the environment and has a relatively high abundance in soil, providing a basis for community ecological research based on phoD (Dai et al., 2019). In contrast, gcd more
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