Xia Qing, Rufty Thomas, Shi Wei
Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, United States.
Front Microbiol. 2021 Mar 23;12:643904. doi: 10.3389/fmicb.2021.643904. eCollection 2021.
Microbes can colonize plant roots to modulate plant health and environmental fitness. Thus, using microbes to improve plant adaptation to biotic and abiotic stresses will be promising to abate the heavy reliance of management systems on synthetic chemicals and limited resource. This is particularly important for turfgrass systems because intensive management for plant available nutrients (e.g., nitrogen), water, and pest control is necessary to maintain a healthy and aesthetic landscape. However, little is known on microbial species and host compatibility in turfgrass root endosphere and rhizosphere. Here, by using marker gene high throughput sequencing approaches we demonstrated that a few bacterial and fungal species prevailed the root endosphere and rhizosphere and were of a broad host spectrum. Irrespective of turfgrass species (bermudagrass, ultradwarf bermudagrass, creeping bentgrass, and tall fescue), defoliation intensities (i.e., mowing height and frequency), turfgrass sites, and sampling time, was predominant in the root endosphere, constituting ∼38% of the total bacterial community, which was much higher than its presence in the bulk soil (∼0.5%) and rhizosphere (∼4.6%). By contrast, and fungal species of the genus were more abundant in the rhizosphere, constituting ∼15 and ∼ 39% of the total bacterial and fungal community, respectively, compared to their respective presence in the bulk soil (∼ 0.1 and 5%) and root endosphere (∼ 0.8 and 0.3%). Such stark contrasts in the microbiome composition between the root endosphere, rhizosphere, and bulk soil were little influenced by turfgrass species, suggesting the broad turfgrass host compatibility of these bacterial and fungal species. Further, their dominance in respective niches were mutually unaffected, implying the possibility of developing a multiple species formula for coping turfgrass with environmental stresses. These species were likely involved in controlling pests, such as infectious nematodes and fungi, decomposing root debris, and helping turfgrass water and nutrient uptake; yet these possibilities need to be further examined.
微生物可以定殖于植物根系，调节植物健康和环境适应性。因此，利用微生物来提高植物对生物和非生物胁迫的适应性，有望减少管理系统对合成化学品和有限资源的严重依赖。这对于草坪草系统尤为重要，因为为了维持健康美观的景观，对植物可利用养分（如氮）、水和病虫害防治进行集约化管理是必要的。然而，对于草坪草根际和根内微生物群落的物种组成以及宿主兼容性，我们所知甚少。在这里，通过使用标记基因高通量测序方法，我们证明了一些细菌和真菌物种在根内和根际中占主导地位，并且具有广泛的宿主谱。无论草坪草种类（狗牙根、超矮生狗牙根、匍匐翦股颖和高羊茅）、落叶强度（即修剪高度和频率）、草坪草生长地点以及采样时间如何， 在根内占主导地位，占细菌群落总数的约38%，远高于其在根际土壤（约0.5%）和根际（约4.6%）中的含量。相比之下， 属的 和真菌物种在根际更为丰富，分别占细菌和真菌群落总数的约15%和39%，而它们在根际土壤（约0.1%和5%）和根内（约0.8%和0.3%）中的含量则较低。根内、根际和根际土壤微生物群落组成的这种鲜明对比，受草坪草种类的影响较小，表明这些细菌和真菌物种具有广泛的草坪草宿主兼容性。此外，它们在各自生态位中的优势地位相互不受影响，这意味着有可能开发一种多物种配方来应对草坪草的环境胁迫。这些物种可能参与控制害虫，如传染性线虫和真菌，分解根残体，并帮助草坪草吸收水分和养分；然而，这些可能性还需要进一步研究。
