Soil acidity with a pH below 5.5 poses a major challenge to global agriculture, affecting approximately 50% of arable land. Al toxicity in acidic soils hampers root growth and nutrient uptake, leading to reduced crop yield and quality. Despite substantial advances in understanding Al resistance in rice, the role of soil microbiota in conferring rice Al resistance to crops remains largely elusive, which restricts the exploitation of targeted beneficial microbes for advancing sustainable agriculture in acidic soils.
An innovative study led by Prof. LIANG Yuting from the Institute of Soil Science, Chinese Academy of Sciences (ISSCAS) in Nanjing, addresses this gap by investigating whether and how a synthetic community of highly Al-resistant bacterial strains isolated from rice rhizosphere could mitigate soil acidification and Al toxicity while increasing crop yield in acidic fields. This study was published in Nature Food on Oct. 2, 2023.
The researchers developed an effective Al-resistant synthetic community (SynCom) consisting of two profoundly Al-resistant strains based on heavy water isotope labeling and Raman spectroscopy. Notably, the SynCom exhibited successful colonization and contributed a remarkable 26.36% increase in rice single panicle yield within acidic fields.
Scientists demonstrated that SynCom engendered pH elevation and decreased Al3+ through a protonation process. Additionally, SynCom promoted phosphate solubilization and reduced the root growth angle for P acquisition in the topsoil. The improved acidic Al-toxic soil environment, combined with a more robust root system, synergistically favored plant-microbe interactions, consequently leading to an enhanced crop yield.
This study concludes that applying Al-resistant SynCom significantly improved rice Al resistance and alleviated P deficiency. More importantly, it offers a microbiota-root-shoot crosstalk solution as an innovative microbiological tool fostering sustainable agriculture in acidic soils.
Fig. Al-resistant SynCom improves rice Al resistance and alleviates P deficiency. (Image by ISSCAS)
Institute of Soil Science, Chinese Academy of Sciences