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van Dam NM, Bouwmeester HJ. Metabolomics in the Rhizosphere: Tapping into Belowground Chemical Communication. TRENDS IN PLANT SCIENCE 2016; 21:256-265. [PMID: 26832948 DOI: 10.1016/j.tplants.2016.01.008] [Citation(s) in RCA: 270] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/18/2015] [Accepted: 01/06/2016] [Indexed: 05/19/2023]
Abstract
The rhizosphere is densely populated with a variety of organisms. Interactions between roots and rhizosphere community members are mostly achieved via chemical communication. Root exudates contain an array of primary and secondary plant metabolites that can attract, deter, or kill belowground insect herbivores, nematodes, and microbes, and inhibit competing plants. Metabolomics of root exudates can potentially help us to better understand this chemical dialogue. The main limitations are the proper sampling of the exudate, the sensitivity of the metabolomics platforms, and the multivariate data analysis to identify causal relations. Novel technologies may help to generate a spatially explicit metabolome of the root and its exudates at a scale that is relevant for the rhizosphere community.
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Affiliation(s)
- Nicole M van Dam
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany; Institute of Ecology, Friedrich Schiller University Jena, Dornburger-Str. 159, 07743 Jena, Germany; Molecular Interaction Ecology, Institute of Water and Wetland Research (IWWR), Radboud University, PO Box 9010, Nijmegen, GL 6500, The Netherlands.
| | - Harro J Bouwmeester
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, PB 6708, The Netherlands.
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Dong L, Xu J, Chen S, Li X, Zuo Y. Mi-flp-18 and Mi-mpk-1 Genes are Potential Targets for Meloidogyne incognita Control. J Parasitol 2016; 102:208-13. [PMID: 26785173 DOI: 10.1645/15-768] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Meloidogyne incognita is a major plant parasite that causes root-knot disease in numerous agricultural crops. This nematode has severely affected greenhouse crops in China. Chemical insecticides are generally used to control this pest, but they have adverse environmental and human toxicity effects; hence, safe and effective strategies for controlling the root-knot nematode (RKN) are necessary. FMRFamide-like peptides (FLPs) have diverse physiological and biological effects on the locomotory, feeding, and reproductive functions of nematodes, and mitogen-activated protein (MAP) kinase plays an important role in the regulation of transcription factors and protein kinases. These candidates are the common targets of RKN control. They are encoded by Mi-flp-18 and Mi-mpk-1 genes, respectively, in M. incognita . In this study, we used the RNA interference (RNAi) method to silence the transcription of these genes and determined the effects on the pathogenicity of RKN in potted plants. Real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) revealed that Mi-mpk-1 gene expression could be reduced by 33% by RNAi. The RNAi-treated infective nematodes were inoculated with dsRNAs of Mi-flp-18 and Mi-mpk-1 in pot experiments. The root-knot numbers were reduced by 51% after Mi-flp-18 RNAi treatment. Further, the relative abundance of Mi-flp-18 was downregulated by 79% in the endoparasitic M. incognita . Mi-flp-18 RNAi treatment decreased egg masses by 92% and egg numbers by 58%. Mi-mpk-1 RNAi treatment reduced the root-knot numbers by 32% and, remarkably, lowered the relative abundance of Mi-mpk-1 in the endoparasitic M. incognita . Egg masses and numbers were reduced by 42 and 22%, respectively, after RKN was inoculated for 35 days with Mi-mpk-1 RNAi. Therefore, Mi-flp-18 and Mi-mpk-1 genes are susceptible to RNAi and can be used as potential targets for RKN control by regulating nematode infection, parasitism, and reproduction.
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Affiliation(s)
- Linlin Dong
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Shilin Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
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Baetz U. Root Exudates as Integral Part of Belowground Plant Defence. BELOWGROUND DEFENCE STRATEGIES IN PLANTS 2016. [DOI: 10.1007/978-3-319-42319-7_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Ding X, Yang M, Huang H, Chuan Y, He X, Li C, Zhu Y, Zhu S. Priming maize resistance by its neighbors: activating 1,4-benzoxazine-3-ones synthesis and defense gene expression to alleviate leaf disease. FRONTIERS IN PLANT SCIENCE 2015; 6:830. [PMID: 26528303 PMCID: PMC4600908 DOI: 10.3389/fpls.2015.00830] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/22/2015] [Indexed: 05/23/2023]
Abstract
Plant disease can be effectively suppressed in intercropping systems. Our previous study demonstrated that neighboring maize plants can restrict the spread of soil-borne pathogens of pepper plants by secreting defense compounds into the soil. However, whether maize plant can receive benefits from its neighboring pepper plants in an intercropping system is little attention. We examined the effects of maize roots treated with elicitors from the pepper pathogen Phytophthora capsici and pepper root exudates on the synthesis of 1,4-benzoxazine-3-ones (BXs), the expression of defense-related genes in maize, and their ability to alleviate the severity of southern corn leaf blight (SCLB) caused by Bipolaris maydis. We found that SCLB was significantly reduced after the above treatments. The contents of 1,4-benzoxazine-3-ones (BXs: DIBOA, DIMBOA, and MBOA) and the expression levels of BX synthesis and defense genes in maize roots and shoots were up-regulated. DIMBOA and MBOA effectively inhibited the mycelium growth of Bipolaris maydis at physiological concentrations in maize shoots. Further studies suggested that the defense related pathways or genes in maize roots and shoots were activated by elicitors from the P. capsici or pepper root exudates. In conclusion, maize increased the levels of BXs and defense gene expression both in roots and shoots after being triggered by root exudates and pathogen from neighboring pepper plants, eventually enhancing its resistance.
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Affiliation(s)
| | | | | | | | | | | | | | - Shusheng Zhu
- Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural UniversityKunming, China
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Dutta TK, Papolu PK, Banakar P, Choudhary D, Sirohi A, Rao U. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes. Front Microbiol 2015; 6:260. [PMID: 25883594 PMCID: PMC4381642 DOI: 10.3389/fmicb.2015.00260] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
Abstract
Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.
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Affiliation(s)
- Tushar K. Dutta
- Division of Nematology, ICAR-Indian Agricultural Research InstituteNew Delhi, India
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Mitsumasu K, Seto Y, Yoshida S. Apoplastic interactions between plants and plant root intruders. FRONTIERS IN PLANT SCIENCE 2015; 6:617. [PMID: 26322059 PMCID: PMC4536382 DOI: 10.3389/fpls.2015.00617] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 07/27/2015] [Indexed: 05/06/2023]
Abstract
Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs) are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.
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Affiliation(s)
- Kanako Mitsumasu
- Graduate School of Science and Technology, Kumamoto University, Chuo-ku, Japan
| | - Yoshiya Seto
- Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Japan
| | - Satoko Yoshida
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- *Correspondence: Satoko Yoshida, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan,
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Plant-plant-microbe mechanisms involved in soil-borne disease suppression on a maize and pepper intercropping system. PLoS One 2014; 9:e115052. [PMID: 25551554 PMCID: PMC4281244 DOI: 10.1371/journal.pone.0115052] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 11/18/2014] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Intercropping systems could increase crop diversity and avoid vulnerability to biotic stresses. Most studies have shown that intercropping can provide relief to crops against wind-dispersed pathogens. However, there was limited data on how the practice of intercropping help crops against soil-borne Phytophthora disease. PRINCIPAL FINDINGS Compared to pepper monoculture, a large scale intercropping study of maize grown between pepper rows reduced disease levels of the soil-borne pepper Phytophthora blight. These reduced disease levels of Phytophthora in the intercropping system were correlated with the ability of maize plants to form a "root wall" that restricted the movement of Phytophthora capsici across rows. Experimentally, it was found that maize roots attracted the zoospores of P. capsici and then inhibited their growth. When maize plants were grown in close proximity to each other, the roots produced and secreted larger quantities of 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and 6-methoxy-2-benzoxazolinone (MBOA). Furthermore, MBOA, benzothiazole (BZO), and 2-(methylthio)-benzothiazole (MBZO) were identified in root exudates of maize and showed antimicrobial activity against P. capsici. CONCLUSIONS Maize could form a "root wall" to restrict the spread of P. capsici across rows in maize and pepper intercropping systems. Antimicrobe compounds secreted by maize root were one of the factors that resulted in the inhibition of P. capsici. These results provide new insights into plant-plant-microbe mechanisms involved in intercropping systems.
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Li C, Kim K. Family of FLP Peptides in Caenorhabditis elegans and Related Nematodes. Front Endocrinol (Lausanne) 2014; 5:150. [PMID: 25352828 PMCID: PMC4196577 DOI: 10.3389/fendo.2014.00150] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 09/09/2014] [Indexed: 11/16/2022] Open
Abstract
Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system have been identified. The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides (FaRPs). These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FaRPs described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and signaling pathways through which they function.
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Affiliation(s)
- Chris Li
- Department of Biology, City College of New York and The Graduate Center, City University of New York, New York, NY, USA
- *Correspondence: Chris Li, 160 Convent Avenue, MR526, New York, NY 10031, USA e-mail: ; Kyuhyung Kim, 333 Techno Jungang-Daero, Hyeonpung-Myeon, Dalseong-Gun, Daegu 711-873, South Korea e-mail:
| | - Kyuhyung Kim
- Department of Brain Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
- *Correspondence: Chris Li, 160 Convent Avenue, MR526, New York, NY 10031, USA e-mail: ; Kyuhyung Kim, 333 Techno Jungang-Daero, Hyeonpung-Myeon, Dalseong-Gun, Daegu 711-873, South Korea e-mail:
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