Heterologous Expression of the AtNPR1 Gene in Olive and Its Effects on Fungal Tolerance

Narváez, Isabel Cómitre; Prieto, Clara Pliego; Palomo-Ríos, Elena; Fresta, Louis; Jiménez-Dı́az, Rafael M.; Trapero-Casas, J. L.; López‐Herrera, C. J.; Arjona-López, Juan M.; Mercado, José A.; Pliego‐Alfaro, Fernando

doi:10.3389/fpls.2020.00308

Cited by 20 publications

(12 citation statements)

References 69 publications

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“…For in vitro-standard propagation of "Ac-18" and "Ac-15" plants, 1.5-to 2.0-cm-long shoots bearing two nodes were multiplied as in Narváez et al (2020) using RP medium [DKW macro-and micronutrients and vitamins as modified by Roussos and Pontikis (2002)] supplemented with 2 mg/L zeatin riboside (Vidoy-Mercado et al, 2012). For rooting, 2-cm-long shoots were cultured for 3 days in basal RP liquid medium supplemented with 10 mg/L IBA and subsequently transferred to basal solid RP medium supplemented with 1 g/L activated charcoal.…”

Section: Olive Plant Materialsmentioning

confidence: 99%

Verticillium dahliae Inoculation and in vitro Propagation Modify the Xylem Microbiome and Disease Reaction to Verticillium Wilt in a Wild Olive Genotype

et al. 2021

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Host resistance is the most practical, long-term, and economically efficient disease control measure for Verticillium wilt in olive caused by the xylem-invading fungus Verticillium dahliae (Vd), and it is at the core of the integrated disease management. Plant’s microbiome at the site of infection may have an influence on the host reaction to pathogens; however, the role of xylem microbial communities in the olive resistance to Vd has been overlooked and remains unexplored to date. This research was focused on elucidating whether in vitro olive propagation may alter the diversity and composition of the xylem-inhabiting microbiome and if those changes may modify the resistance response that a wild olive clone shows to the highly virulent defoliating (D) pathotype of Vd. Results indicated that although there were differences in microbial communities among the different propagation methodologies, most substantial changes occurred when plants were inoculated with Vd, regardless of whether the infection process took place, with a significant increase in the diversity of bacterial communities when the pathogen was present in the soil. Furthermore, it was noticeable that olive plants multiplied under in vitro conditions developed a susceptible reaction to D Vd, characterized by severe wilting symptoms and 100% vascular infection. Moreover, those in vitro propagated plants showed an altered xylem microbiome with a decrease in total OTU numbers as compared to that of plants multiplied under non-aseptic conditions. Overall, 10 keystone bacterial genera were detected in olive xylem regardless of infection by Vd and the propagation procedure of plants (in vitro vs nursery), with Cutibacterium (36.85%), Pseudomonas (20.93%), Anoxybacillus (6.28%), Staphylococcus (4.95%), Methylobacterium-Methylorubrum (3.91%), and Bradyrhizobium (3.54%) being the most abundant. Pseudomonas spp. appeared as the most predominant bacterial group in micropropagated plants and Anoxybacillus appeared as a keystone bacterium in Vd-inoculated plants irrespective of their propagation process. Our results are the first to show a breakdown of resistance to Vd in a wild olive that potentially may be related to a modification of its xylem microbiome and will help to expand our knowledge of the role of indigenous xylem microbiome on host resistance, which can be of use to fight against main vascular diseases of olive.

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Section: Olive Plant Materialsmentioning

confidence: 99%

Verticillium dahliae Inoculation and in vitro Propagation Modify the Xylem Microbiome and Disease Reaction to Verticillium Wilt in a Wild Olive Genotype

et al. 2021

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“…The NPR1 gene is a key regulator in the systemic acquired resistance (SAR) pathway. Regrettably, the heterologous expression of the NPR1 gene in transgenic olives did not confer resistance to the D pathotype of V. dahliae, although it improved the plant response to the ND pathotype [121].…”

Section: The Continuous Search For Sources Of Vwo Tolerance/resistancementioning

confidence: 93%

Verticillium Wilt of Olive and Its Control: What Did We Learn during the Last Decade?

Montes-Osuna

Mercado‐Blanco

2020

Plants

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Verticillium (Verticillium dahliae Kleb.) wilt is one of the most devastating diseases affecting olive (Olea europaea L. subsp. europaea var. europaea) cultivation. Its effective control strongly relies on integrated management strategies. Olive cultivation systems are experiencing important changes (e.g., high-density orchards, etc.) aiming at improving productivity. The impact of these changes on soil biology and the incidence/severity of olive pests and diseases has not yet been sufficiently evaluated. A comprehensive understanding of the biology of the pathogen and its populations, the epidemiological factors contributing to exacerbating the disease, the underlying mechanisms of tolerance/resistance, and the involvement of the olive-associated microbiota in the tree’s health is needed. This knowledge will be instrumental to developing more effective control measures to confront the disease in regions where the pathogen is present, or to exclude it from V. dahliae-free areas. This review compiles the most recent advances achieved to understand the olive–V. dahliae interaction as well as measures to control the disease. Aspects such as the molecular basis of the host–pathogen interaction, the identification of new biocontrol agents, the implementation of “-omics” approaches to unravel the basis of disease tolerance, and the utilization of remote sensing technology for the early detection of pathogen attacks are highlighted.

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“…The size of the transgenes inserted could affect regeneration efficiency; hence, the protocol described above was adapted to different constructs by employing a progressive selection strategy, which would be less stressful for the globular embryos than the continuous high selection pressure used in the original protocol [ 58 ]. It is then recommended to start the selection phase using a medium supplemented with 50 mg/L paromomycin and progressively increase the concentration to reach 150 mg/L at the end of the process.…”

Section: Genetic Transformation Proceduresmentioning

confidence: 99%

“…Transgenic AtNPR1 cotton plants were also resistant to non-defoliating (ND) strains of V. dahliae , but not to defoliating (D) ones [ 84 ]. In olive, three transgenic lines expressing the AtNPR1 gene under the control of the CaMV35S promoter were recovered and tested against V. dahliae , D and ND pathotypes, and R. necatrix [ 58 ]. Two of these lines showed an overexpression of a PR1-homologue gene, but endochitinase activity levels were not affected.…”

Section: Genetic Transformation With Genes Of Interestmentioning

confidence: 99%

Olive (Olea europaea L.) Genetic Transformation: Current Status and Future Prospects

Palomo-Ríos

Narváez

Pliego‐Alfaro

et al. 2021

Genes

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Olive (Olea europaea L.) is the most characteristic and important oil crop of the Mediterranean region. Traditional olive cultivation is based on few tens cultivars of ancient origin. To improve this crop, novel selections with higher tolerance to biotic and abiotic stress, adaptable to high-density planting systems and resilient to climate change are needed; however, breeding programs are hindered by the long juvenile period of this species and few improved genotypes have been released so far. Genetic transformation could be of great value, in the near future, to develop new varieties or rootstocks in a shorter time; in addition, it has currently become an essential tool for functional genomic studies. The recalcitrance of olive tissues to their in vitro manipulation has been the main bottleneck in the development of genetic transformation procedures in this species; however, some important traits such as fungal resistance, flowering or lipid composition have successfully been manipulated through the genetic transformation of somatic embryos of juvenile or adult origin, providing a proof of the potential role that this technology could have in olive improvement. However, the optimization of these protocols for explants of adult origin is a prerequisite to obtain useful materials for the olive industry. In this review, initially, factors affecting plant regeneration via somatic embryogenesis are discussed. Subsequently, the different transformation approaches explored in olive are reviewed. Finally, transgenic experiments with genes of interest undertaken to manipulate selected traits are discussed.

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Heterologous Expression of the AtNPR1 Gene in Olive and Its Effects on Fungal Tolerance

Cited by 20 publications

References 69 publications

Verticillium dahliae Inoculation and in vitro Propagation Modify the Xylem Microbiome and Disease Reaction to Verticillium Wilt in a Wild Olive Genotype

Verticillium dahliae Inoculation and in vitro Propagation Modify the Xylem Microbiome and Disease Reaction to Verticillium Wilt in a Wild Olive Genotype

Verticillium Wilt of Olive and Its Control: What Did We Learn during the Last Decade?

Olive (Olea europaea L.) Genetic Transformation: Current Status and Future Prospects

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