Eaton William D, Hamilton Debra A, Chen Wen, Lemenze Alexander, Soteropoulos Patricia
Biology Department, Pace University, One Pace Plaza, New York, NY 10038, U.S.A.
University for Peace, El Rodeo de Mora, San José, Cd Colón, Costa Rica.
AIMS Microbiol. 2024 Jul 23;10(3):572-595. doi: 10.3934/microbiol.2024027. eCollection 2024.
Leguminous tree root nodule nitrogen-fixing bacteria are critical for recuperation of soil C and N cycle processes after disturbance in tropical forests, while other nodule-associated bacteria (NAB) may enhance nodule development and activity, and plant growth. However, little is known of these root nodule microbiomes. Through DNA analysis, we evaluated the bacterial taxa associated with the root nodules of the 1-year-old, 2-year-old, 13-year-old, and old growth trees in a cloud forest. was the dominant taxon found in all nodules at 63.16% to 85.71% mean percent sequences (MPS) of the total nodule bacterial DNA and was found in the youngest nodules examined (1 year old), suggesting that it is the primary nodular bacteria. There were 26 other NAB genera with collective MPS levels between 7.4% to 12.2%, while 15 of these genera were found in the Bulk Forest soils at collective MPS levels of 4.6%. These bacterial community compositions were different between the NAB and Bulk Forest soils, suggesting the NAB became concentrated within the root nodules, resulting in communities with different compositions from the Bulk Forest soils. Twenty-three of the 26 NAB genera were previously identified with the potential to perform 9 plant growth promoting (PGP) activities, suggesting their importance in root nodule development and plant growth. These NAB communities appeared to successionally develop over time into more complex taxonomic communities, which is consistent with the outcome of advanced microbial communities following succession. The presence of both and the NAB communities in the nodules across all ages of tree roots, and the potential for PGP activities linked with most of the NAB genera, suggest the importance of and the NAB community for nodule development and enhanced development and growth of throughout its lifespan, and most critically in the younger plants.
豆科树根瘤固氮细菌对于热带森林扰动后土壤碳和氮循环过程的恢复至关重要，而其他与根瘤相关的细菌（NAB）可能会促进根瘤发育和活性以及植物生长。然而，人们对这些根瘤微生物群落知之甚少。通过DNA分析，我们评估了云雾森林中1岁、2岁、13岁和老龄树木根瘤相关的细菌分类群。[具体细菌名称]是在所有根瘤中发现的优势分类群，占根瘤细菌总DNA平均序列百分比（MPS）的63.16%至85.71%，并且在检测的最年轻根瘤（1岁）中也有发现，这表明它是主要的根瘤细菌。还有26个其他NAB属，其集体MPS水平在7.4%至12.2%之间，而其中15个属在森林土壤中的集体MPS水平为4.6%。这些细菌群落组成在NAB和森林土壤之间有所不同，这表明NAB在根瘤中富集，导致其群落组成与森林土壤不同。26个NAB属中的23个先前已被确定具有9种促进植物生长（PGP）的活性，这表明它们在根瘤发育和植物生长中具有重要性。这些NAB群落似乎随着时间的推移逐渐演变成更复杂的分类群落，这与演替后高级微生物群落的结果一致。在所有年龄段树根的根瘤中都存在[具体细菌名称]和NAB群落，并且大多数NAB属都具有PGP活性的潜力，这表明[具体细菌名称]和NAB群落在根瘤发育以及[植物名称]整个生命周期的发育和生长增强中具有重要性，在幼龄植物中最为关键。
