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Lv H, Li X, He D, Chen X, Liu M, Lan Y, Zhao J, Wang H, Yan Z. Genotype-Controlled Vertical Transmission Exerts Selective Pressure on Community Assembly of Salvia miltiorrhiza. MICROBIAL ECOLOGY 2023; 86:2934-2948. [PMID: 37667132 DOI: 10.1007/s00248-023-02295-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 08/27/2023] [Indexed: 09/06/2023]
Abstract
The plant's endophytic fungi play an important role in promoting host development and metabolism. Studies have shown that the factors affecting the assembly of the endophyte community mainly include host genotype, vertical transmission, and soil origin. However, we do not know the role of vertically transmitted endohytic fungi influences on the host-plant's endophytic community assembly. Salvia miltiorrhiza from three production areas were used as research objects; we constructed three production area genotypes of S. miltiorrhiza regenerated seedlings simultaneously. Based on high-throughput sequencing, we analyzed the effects of genotype, soil origin, and vertical transmission on endophytic fungal communities. The results show that the community of soil origins significantly affected the endophytic fungal community in the regenerated seedlings of S. miltiorrhiza. The influence of genotype on community composition occurs through a specific mechanism. Genotype may selectively screen certain communities into the seed, thereby exerting selection pressure on the community composition process of offspring. As the number of offspring increases gradually, the microbiota, controlled by genotype and transmitted vertically, stabilizes, ultimately resulting in a significant effect of genotype on community composition.Furthermore, we observed that the taxa influencing the active ingredients are also selected as the vertically transmitted community. Moreover, the absence of an initial vertically transmitted community in S. miltiorrhiza makes it more vulnerable to infection by pathogenic fungi. Therefore, it is crucial to investigate and comprehend the selection model of the vertically transmitted community under varying genotypes and soil conditions. This research holds significant implications for enhancing the quality and yield of medicinal plants and economic crops.
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Affiliation(s)
- Hongyang Lv
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaoyu Li
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dongmei He
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xin Chen
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Min Liu
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yin Lan
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
- Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jin Zhao
- State Key Laboratory of Quality Research in Chinese Medicine, Chengdu, China.
- Institute of Chinese Medical Sciences, University of Macau, Taipa, China.
| | - Hai Wang
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China.
- Chengdu University of Traditional Chinese Medicine, Chengdu, China.
| | - Zhuyun Yan
- State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China.
- Chengdu University of Traditional Chinese Medicine, Chengdu, China.
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Abstract
Ralstonia solanacearum species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is phc quorum sensing (QS). It regulates the expression of about 30% of all genes, including those related to cellular activity, primary and secondary metabolism, pathogenicity, and more. The phc regulatory elements encoded by the phcBSRQ operon and phcA gene play vital roles. RSSC strains use methyl 3-hydroxymyristate (3-OH MAME) or methyl 3-hydroxypalmitate (3-OH PAME) as the QS signal. Each type of RSSC strain has specificity in generating and receiving its QS signal, but their signaling pathways might not differ significantly. In this review, I describe the genetic and biochemical factors involved in QS signal input and the regulatory network and summarize control of the phc QS system, new cell-cell communications, and QS-dependent interactions with soil fungi.
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Affiliation(s)
- Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan;
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Tsumori C, Matsuo S, Murai Y, Kai K. Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores. Microbiol Spectr 2023; 11:e0003623. [PMID: 37367297 PMCID: PMC10433826 DOI: 10.1128/spectrum.00036-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted. In this study, we report that quorum sensing (QS), which is a bacterial cell-cell communication, is important for RSSC to invade the fungus Fusarium oxysporum (Fo). ΔphcB, a deletion mutant of QS signal synthase, lost the ability to both produce ralstonins and invade Fo chlamydospores. The QS signal methyl 3-hydroxymyristate rescued these disabilities. In contrast, exogenous ralstonin A, while inducing Fo chlamydospores, failed to rescue the invasive ability. Gene-deletion and -complementation experiments revealed that the QS-dependent production of extracellular polysaccharide I (EPS I) is essential for this invasion. The RSSC cells adhered to Fo hyphae and formed biofilms there before inducing chlamydospores. This biofilm formation was not observed in the EPS I- or ralstonin-deficient mutant. Microscopic analysis showed that RSSC infection resulted in the death of Fo chlamydospores. Altogether, we report that the RSSC QS system is important for this lethal endoparasitism. Among the factors regulated by the QS system, ralstonins, EPS I, and biofilm are important parasitic factors. IMPORTANCE Ralstonia solanacearum species complex (RSSC) strains infect both plants and fungi. The phc quorum-sensing (QS) system of RSSC is important for parasitism on plants, because it allows them to invade and proliferate within the hosts by causing appropriate activation of the system at each infection step. In this study, we confirm that ralstonin A is important not only for Fusarium oxysporum (Fo) chlamydospore induction but also for RSSC biofilm formation on Fo hyphae. Extracellular polysaccharide I (EPS I) is also essential for biofilm formation, while the phc QS system controls these factors in terms of production. The present results advocate a new QS-dependent mechanism for the process by which a bacterium invades a fungus.
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Affiliation(s)
- Chiaki Tsumori
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Shoma Matsuo
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Yuta Murai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
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Colón Carrión N, Troche CL, Arnold AE. Communities of endophytic fungi in a Puerto Rican rainforest vary along a gradient of disturbance due to Hurricane Maria. Ecol Evol 2022; 12:e9618. [PMID: 36532133 PMCID: PMC9750846 DOI: 10.1002/ece3.9618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/18/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022] Open
Abstract
Increases in the frequency and intensity of hurricanes influence the structure, function, and resilience of Caribbean forests. Trees in such forests harbor diverse fungal endophytes within leaves and roots. Fungal endophytes often are important for plant health and stress responses, but how their communities are impacted by hurricanes is not well known. We measured forest disturbance in Carite State Forest in Puerto Rico ca. 16 months after the passage of Hurricane Maria, a Category 4 storm. In three sites, each comprising three plots representing a local gradient of hurricane disturbance, we evaluated soil chemistry and used culture-free analyses to measure richness, phylogenetic diversity, and composition of endophyte communities in leaves and roots. We found that endophyte richness did not vary significantly among plant families or as a function of soil chemistry. Instead, leaf endophytes peaked in richness and decreased in phylogenetic diversity at intermediate levels of disturbance. Root endophytes did not show such variation, but both leaf- and root endophyte communities differed in species composition as a function of disturbance across the forest. Locations with less disturbance typically hosted distinctive assemblages of foliar endophytes, whereas more disturbed locations had more regionally homogeneous endophyte communities. Together, our results show that changes in endophyte richness and phylogenetic diversity can be detected in aboveground tissues more than a year after major storms. In turn, pervasive shifts in endophyte community composition both aboveground and belowground suggest a subtle and lasting effect of hurricanes that merits further study, potentially contributing to the promotion of spatially heterogeneous endophyte assemblages at a landscape scale in these diverse island forests.
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Affiliation(s)
| | | | - A. Elizabeth Arnold
- School of Plant SciencesUniversity of ArizonaTucsonArizonaUSA
- Department of Ecology and Evolutionary BiologyUniversity of ArizonaTucsonArizonaUSA
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