Effect of Karst Microhabitats on the Structure and Function of the Rhizosphere Soil Microbial Community of Rhododendron pudingense

Abstract

Soil microbes play an important role in the microbial circulation and energy flow of ecosystems. In order to understand the change in the rhizosphere soil microbial community structure and function in the heterogeneous karst habitats, the nutrient content and enzyme activity were analyzed, and Illumina MiSeq high-throughput sequencing technology was used to detect the composition, quantity and functional types of the rhizosphere soil microbial community in Rhododendron pudingense under three kinds of karst microhabitats (soil surface, rock gully and rock surface) in Wangmo Country (WM), Zhenning Country (ZN) and Qinglong Country (QL). The results showed that SS and RG microhabitats had a higher nutrient content and enzyme activity, while RS had the lowest. At the phylum level, Proteobacteria and Actinomycetes were dominant in terms of bacteria, while Ascomycota and Basidiomycotina were dominant in terms of fungi. There was no significant difference in microbial diversity among different karst microhabitats (p > 0.05). At the microbial genus level, there were some differences in species composition among the three karst microhabitats, which may lead to soil heterogeneity in karst microhabitats. WM was a little different from ZN and QL. The results of PCoA showed that the community composition of RG and RS was more similar to that of SS. There was no significant difference in microbial functional types among different microhabitats (p > 0.05). Only the abundance of pathothoph-symbiothoph fungi in RG was significantly higher than that in RS (p < 0.05). The main function of bacteria was metabolism, and saprophytic and symbiotic fungi were the dominant fungal group. In conclusion, soil organic carbon and alkaline phosphatase are important factors affecting the level distribution of microflora in different karst microhabitats. R. pudingense in the SS and RG microhabitats has better soil conditions, which may require protection for the plants in the RS microhabitat. The current study results can provide a theoretical basis for the adaptation mechanism of Rhododendron pudingense to the karst microhabitat.

Unraveling plant adaptation to nitrogen limitation from enzyme stoichiometry aspect in Karst soils: a case study of Rhododendron Pudingense

“…Our findings suggest that various karst microenvironments encounter differing degrees of nitrogen limitation, and R. pudingense primarily adapts its nutrient allocation within its body to deal with nitrogen-limited conditions. These microenvironments might also impact the stability of soil aggregates ( Wei et al., 2022 ), the microbiome community ( Yuan et al., 2023 ), and other factors that alter the effectiveness of soil nutrients and thus affect the nutrient allocation of R. pudingense .…”

“…( Table 1 ). Based on the research results of Yuan et al. (2023) , this study divided the karst microhabitats and selected the most typical microhabitats with R. pudingense , namely rock surface (RS), rock gully (RG), and soil surface (SS) within the plot, according to the criteria shown in Table S1 .…”

“…Interestingly, while native Rhododendron plants mainly grow in acidic soils ( Su et al., 2020 ), this species thrives only in weak alkaline soil in karst areas, highlighting its unique adaptation mechanisms that require further study. Notably, study of Rhododendron pudingense is significant due to its ecological importance, unique characteristics, and potential contributions to conservation, medicine, and horticulture ( Yuan et al., 2023 ). This species plays a role in supporting biodiversity within its habitat, and its distinctive features add to our understanding of plant diversity.…”

Study on the characteristics of genetic diversity of different populations of Guizhou endemic plant Rhododendron pudingense based on microsatellite markers

“…Therefore, it is of utmost importance to protect this species, as both genetic resource conservation and plant breeding require assessment of the genetic diversity and outcomes of endangered species [ 3 , 4 ]. To date, potential habitats, population structure, spatial distribution patterns, soil microbial community structure, functional diversity, and enzyme activities of R. pudingense plants have been reported in previous researchs [ 2 , 5 – 7 ], the genetic diversity and population structure of R. pudingense population were still unclear, which may cause it difficult to plan conservation strategies for this R. pudingense .…”

Study on the characteristics of genetic diversity of different populations of Guizhou endemic plant Rhododendron pudingense based on SSR molecular markers

“…Therefore, it is of utmost importance to protect this species, as both genetic resource conservation and plant breeding require assessment of the genetic diversity and outcomes of endangered species [3,4]. To date, potential habitats, population structure, spatial distribution patterns, soil microbial community structure, functional diversity, and enzyme activities of R. pudingense plants have been reported in previous researchs [2,[5][6][7], the genetic diversity and population structure of R. pudingense population were still unclear, which may cause it di cult to plan conservation strategies for this R. pudingense.…”