Ecological niche selection shapes the assembly and diversity of microbial communities in Casuarina equisetifolia L.

Abstract

The plant microbiome profoundly affects many aspects of host performance; however, the ecological processes by which plant hosts govern microbiome assembly, function, and dispersal remain largely unknown. Here, we investigated the bacterial and fungal communities in multiple compartment niches (bulk soil, rhizosphere soil, root endosphere, phylloplane, and leaf endosphere) of Casuarina equisetifolia L. at three developmental stages in Hainan Province, China. We found that microbiome assemblages along the soil–plant continuum were shaped by the compartment niches. Bacterial diversity and richness decreased from the soils to roots to leaves, with the highest network complexity found in the roots and the lowest found in the phylloplane. However, fungal diversity gradually increased from the soils to roots to phyllosphere, whereas fungal richness decreased from the soils to roots but increased from the roots to phyllosphere; the greatest network complexity was found in bulk soils and the lowest was found in the roots. Different biomarker taxa occurred in the different ecological niches. Bacterial and fungal communities exhibited distinct ecological functions; the former played important roles in maintaining plant growth and providing nutrients, whereas the latter predominantly decomposed organic matter. The bacterial community of C. equisetifolia mostly originated from bulk soil, whereas the fungal community was mainly derived from rhizosphere soil and air. Leaf endophytes were positively correlated with organic carbon, and root and soil microorganisms were positively correlated with total nitrogen, total phosphorus, and total potassium. Our findings provide empirical evidence for plant–microbiome interactions and contribute to future research on non-crop management and the manipulation of non-crop microbiomes.

Fungal community composition and function in different spring rapeseeds on the Qinghai-Tibet Plateau, China

“…Additionally, the unique fungal genera in this study were ranked as follows: rhizosphere soil > leaf > root > stem among different niches (Fig. 5B), attributed to the fact that the fungal communities in oilseed rape mainly originate from the soil and are sequentially ltered by the plant niches (Lin et al 2022). Besides, above-ground plant tissues of oilseed rape can harbor a diverse range of fungal taxa, as plant leaves release a wide range of volatile organic compounds that can in uence microbial colonization (Whipps et al 2008).…”

“…Therefore, it can be inferred that these fungi may also derive from the surrounding environment. A previous study suggested that air, dust, and rainwater are the primary sources of the phylloplane fungal community (Lin et al 2022). Furthermore, symbiotic microorganisms can have bene cial, neutral, or detrimental impacts on plant growth (Li et al 2022c).…”

Response of Phyllosphere and Rhizosphere Microbial Communities to Salt Stress of Tamarix chinensis

“…Among fungi, Ascomycota and Basidiomycota were the dominant phyla in the rhizosphere of T. chinensis , but their composition was also affected by salt stress [ 35 ]. In addition, the network relationships among microorganisms can also reflect the occupation of ecological niches by each OTU [ 38 ]. In our study, salt stress increased the positive correlation among OTUs of rhizosphere bacteria of T. chinensis , which was speculated to be the result of cooperative resistance to saline habitats among OTUs [ 33 ].…”

Beyond defense: Glucosinolate structural diversity shapes recruitment of a metabolic network of leaf-associated bacteria

“…In order to successfully colonize leaves, all bacteria need to overcome several hurdles, such that the taxa that finally reach the surface and endosphere of plant leaves have been filtered by several factors ( 5 , 6 ). First, to find their way onto or into the leaf, microbes must overcome physical hurdles such as low water availability ( 7 ) and regulated stomatal openings ( 8 ).…”