Lian Tengxiang, Cheng Lang, Liu Qi, Yu Taobing, Cai Zhandong, Nian Hai, Hartmann Martin
The State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, Guangdong, China.
The Key Laboratory of Plant Molecular Breeding of Guangdong Province, College of Agriculture, South China Agricultural University, Guangzhou, Guangdong, China.
ISME Commun. 2023 Jul 11;3(1):71. doi: 10.1038/s43705-023-00282-0.
Waterlogging in soil can limit the availability of nitrogen to plants by promoting denitrification and reducing nitrogen fixation and nitrification. The root-associated microorganisms that determine nitrogen availability at the root-soil interface can be influenced by plant genotype and soil type, which potentially alters the nitrogen uptake capacity of plants in waterlogged soils. In a greenhouse experiment, two soybean genotypes with contrasting capacities to resist waterlogging stress were grown in Udic Argosol and Haplic Alisol soils with and without waterlogging, respectively. Using isotope labeling, high-throughput amplicon sequencing and qPCR, we show that waterlogging negatively affects soybean yield and nitrogen absorption from fertilizer, atmosphere, and soil. These effects were soil-dependent and more pronounced in the waterlogging-sensitive than tolerant genotype. The tolerant genotype harbored more ammonia oxidizers and less nitrous oxide reducers. Anaerobic, nitrogen-fixing, denitrifying and iron-reducing bacteria such as Geobacter/Geomonas, Sphingomonas, Candidatus Koribacter, and Desulfosporosinus were proportionally enriched in association with the tolerant genotype under waterlogging. These changes in the rhizosphere microbiome might ultimately help the plant to improve nitrogen uptake under waterlogged, anoxic conditions. This research contributes to a better understanding of the adaptability of soybean genotypes under waterlogging stress and might help to formulate fertilization strategies that improve nitrogen use efficiency of soybean. Schematic representation of the effects of waterlogging on nitrogen uptake and rhizosphere microbiota in dependence of soil type and soybean genotype.
土壤渍水会通过促进反硝化作用、减少固氮作用和硝化作用来限制植物对氮的吸收。决定根际土壤界面氮有效性的根际微生物会受到植物基因型和土壤类型的影响，这可能会改变渍水土壤中植物的氮吸收能力。在一项温室试验中，分别在淹水和未淹水的潮土和潜育淋溶土中种植了两种耐渍水胁迫能力不同的大豆基因型。通过同位素标记、高通量扩增子测序和定量聚合酶链反应，我们发现渍水对大豆产量以及从肥料、大气和土壤中吸收氮均有负面影响。这些影响因土壤类型而异，对渍水敏感的基因型比耐渍水基因型更为明显。耐渍水基因型中氨氧化菌较多，而一氧化二氮还原菌较少。在渍水条件下，与耐渍水基因型相关联的厌氧、固氮、反硝化和铁还原细菌，如地杆菌属/地单胞菌属、鞘氨醇单胞菌属、类芽孢杆菌属和脱硫孢菌属，比例相对富集。根际微生物群的这些变化最终可能有助于植物在渍水缺氧条件下提高氮吸收。这项研究有助于更好地理解大豆基因型在渍水胁迫下的适应性，并可能有助于制定提高大豆氮利用效率的施肥策略。渍水对氮吸收和根际微生物群的影响示意图，该影响取决于土壤类型和大豆基因型。
