Hone Holly, Li Tongda, Kaur Jatinder, Wood Jennifer L, Sawbridge Timothy
Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC, Australia.
DairyBio, AgriBio, Centre for AgriBioscience, Bundoora, VIC, Australia.
Front Microbiol. 2025 Apr 28;16:1568162. doi: 10.3389/fmicb.2025.1568162. eCollection 2025.
The potential of phosphate-solubilizing microbes (PSMs) to enhance plant phosphorus uptake and reduce fertilizer dependency remains underutilized. This is partially attributable to frequent biofertilizer-farming system misalignments that reduce efficacy, and an incomplete understanding of underlying mechanisms. This study explored the seed microbiomes of nine Australian lucerne cultivars to identify and characterize high-efficiency PSMs. From a library of 223 isolates, 94 (42%) exhibited phosphate solubilization activity on Pikovskaya agar, with 15 showing high efficiency (PSI > 1.5). Genomic analysis revealed that the "high-efficiency" phosphate-solubilizing microbes belonged to four genera (, , , ), including novel strains and species. However, key canonical genes, such as operon and , did not reliably predict phenotype, highlighting the limitations of predictions. Mutagenesis of the high-efficiency isolate Lu_Sq_004 generated mutants with enhanced and null solubilization phenotypes, revealing the potential role of "auxiliary" genes in downstream function of solubilization pathways. Inoculation studies with lucerne seedlings demonstrated a significant increase in shoot length ( < 0.05) following treatment with the enhanced-solubilization mutant, indicating a promising plant growth-promotion effect. These findings highlight the potential of more personalized "system-appropriate" biofertilizers and underscore the importance of integrating genomic, phenotypic, and analyses to validate function. Further research is required to investigate links between genomic markers and functional outcomes to optimize the development of sustainable agricultural inputs.
解磷微生物（PSMs）增强植物对磷的吸收并减少对肥料依赖的潜力尚未得到充分利用。这部分归因于生物肥料与耕作系统频繁不匹配导致功效降低，以及对潜在机制的理解不完整。本研究探索了9个澳大利亚苜蓿品种的种子微生物群，以鉴定和表征高效解磷微生物。在223个分离株文库中，94个（42%）在皮氏罗兹琼脂上表现出解磷活性，其中15个表现出高效（PSI>1.5）。基因组分析表明，“高效”解磷微生物属于4个属（，，，），包括新菌株和新物种。然而，关键的典型基因，如操纵子和，不能可靠地预测表型，突出了预测的局限性。高效分离株Lu_Sq_004的诱变产生了具有增强和解磷表型缺失的突变体，揭示了“辅助”基因在解磷途径下游功能中的潜在作用。苜蓿幼苗接种研究表明，用增强解磷突变体处理后，地上部长度显著增加（<0.05），表明具有良好的促进植物生长效果。这些发现突出了更个性化的“系统适配”生物肥料的潜力，并强调了整合基因组、表型和分析以验证功能的重要性。需要进一步研究以调查基因组标记与功能结果之间的联系，以优化可持续农业投入的开发。
