Interactions between rootstocks and compost influence the active rhizosphere bacterial communities in citrus

Abstract

Background While the rootstock genotype (belowground part of a plant) can impact rhizosphere microbial communities, few studies have examined the relationships between rootstock genotype-based recruitment of active rhizosphere bacterial communities and the availability of root nutrients for plant uptake. Rootstocks are developed to provide resistance to disease or tolerance of abiotic stresses, and compost application is a common practice to also control biotic and abiotic stresses in crops. In this field study, we examined: (i) the effect of four citrus rootstocks and/or compost application on the abundance, diversity, composition, and predicted functionality of active rhizosphere bacterial communities, and (ii) the relationships between active rhizosphere bacterial communities and root nutrient concentrations, with identification of bacterial taxa significantly correlated with changes in root nutrients in the rhizosphere. Results The rootstock genotype determined differences in the diversity of active rhizosphere bacterial communities and also impacted how compost altered the abundance, diversity, composition, and predicted functions of these active communities. Variations in the active bacterial rhizobiome were strongly linked to root nutrient cycling, and these interactions were root-nutrient- and rootstock-specific. Direct positive relationships between enriched taxa in treated soils and specific root nutrients were detected, and potentially important taxa for root nutrient uptake were identified. Significant differences in specific predicted functions were related to soil nutrient cycling (carbon, nitrogen, and tryptophan metabolisms) in the active bacterial rhizobiome among rootstocks, particularly in soils treated with compost. Conclusions This study illustrates that interactions between citrus rootstocks and compost can influence active rhizosphere bacterial communities, which impact root nutrient concentrations. In particular, the response of the rhizobiome bacterial abundance, diversity, and community composition to compost was determined by the rootstock. Specific bacterial taxa therefore appear to be driving changes in root nutrient concentrations in the active rhizobiome of different citrus rootstocks. Several potential functions of active bacterial rhizobiomes recruited by different citrus rootstocks did not appear to be redundant but rather rootstock-specific. Together, these findings have important agronomic implications as they indicate the potential for agricultural production systems to maximize benefits from rhizobiomes through the choice of selected rootstocks and the application of compost.

Exploring the Core Bacteria and Functional Traits in Pecan (Carya illinoinensis) Rhizosphere

“…Most fruit tree crops are composed of the following two parts: the aboveground fruit-bearing part (the scion) and the below ground part (the rootstock), which provides anchorage and is responsible for water and nutrient uptake. The rootstocks could maximize benefits from rhizobiomes ( 41 ), which help plants to resist disease and tolerate the abiotic stresses. Thus, the core of rhizosphere microbes on pecan may represent candidate taxa for designing microbial consortia with a potential to serve as biofertilizers ( 42 ) and the identification of the core microbes provides a useful starting point for future studies that could exploit synthetic communities to determine the interaction between microbes in their interactions with pecan itself.…”

间作槟榔调控咖啡根际微生物群落结构及功能促进咖啡植株发育

“…较高的过氧化氢 酶活性可能说明土壤中存在一定水平的氧化应激, 可 能会影响微生物生存和功能 [44] . 综上, 土壤速效磷、 寄主植物, 植物则为Bradyrhizobium提供生长和繁殖 所需的碳源 [45] , 这种共生关系有助于提高咖啡植株对 氮的吸收利用效率, 促进土壤中氮循环. Streptomyces 具有抑制植物病害的能力, 主要通过竞争资源、产生 抗生素、诱导植物系统抗性等, 抑制病原菌生长繁殖, 促使植物健康生长 [46] .…”

Deciphering key factors in pathogen-suppressive microbiome assembly in the rhizosphere

“…Various investigations into organic and conventional systems ( Bonanomi et al., 2016 ; Cavicchioli et al., 2019 ; Obieze et al., 2023 ) have revealed variations in microbial composition and diversity. Moreover, studies have highlighted the taxonomic and functional changes attributed to organic nutrient amendments ( Cui et al., 2018 ; Castellano-Hinojosa et al., 2023 ). Microbial diversity in a Chinese fir ( Cunninghamia lanceolata ) monoculture plantation interacts strongly with dissolved organic matter ( Li et al., 2021 ).…”