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Rodrigues da Silva A, da Costa Silva D, Dos Santos Pinto KN, Santos Filho HP, Coelho Filho MA, Dos Santos Soares Filho W, Ferreira CF, da Silva Gesteira A. Epigenetic responses to Phytophthora citrophthora gummosis in citrus. Plant Sci 2021; 313:111082. [PMID: 34763867 DOI: 10.1016/j.plantsci.2021.111082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 06/13/2023]
Abstract
Studies show that DNA methylation is associated with plant immunity but little is known as to how this epigenetic mechanism assists plants in adjusting their responses to biotic stress, especially when interacting with an hemibiotrophic pathogen such as citrus Phytophthora. The aim of the present study was to assess the effects of scion-rootstock interaction on plant resistance to P. citrophthora infection and DNA methylation patterns in 'Pera' sweet orange and 'Tahiti' acid lime grafted onto 'Rangpur' lime and 'Tropical' sunki rootstocks reinoculated with P. citrophthora. Results showed that reinoculated plants of the 'Pera' sweet orange/'Rangpur' lime and 'Tahiti' acid lime/'Tropical' sunki combinations with more and less sensitive varieties to Phytophthora, presented smaller stem lesions and increased frequency of full methylation and hemimethylation rates, compared to inoculated plants. In contrast, 'Tahiti' acid lime/'Rangpur' lime, two highly sensitive varieties, and 'Pera'/'Tropical' sunki, two much less sensitive varieties, showed high increases in the frequency of hemimethylation and non-methylation levels. Results suggest that in citrus, both the scion-rootstock interaction and DNA methylation affect the response to P. citrophthora infection. Reinoculated plants, depending on the combination, showed changes in intracellular hyphae growth through the formation of sets of fibers and crystal accumulation in the periderm, cortex, and phloem. In addition, starch grain concentration was higher in reinoculated plants in comparison to inoculated plants. These findings support the assumption that DNA methylation is a plant defense mechanism and therefore may be exploited to improve the response of plants to the gummosis of P. citrophthora in citrus.
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Affiliation(s)
- Adielle Rodrigues da Silva
- Departamento de Biologia, Centro de Genética e Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, 45662-900, Brazil
| | - Delmira da Costa Silva
- Departamento de Biologia, Centro de Genética e Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, 45662-900, Brazil
| | | | | | | | | | | | - Abelmon da Silva Gesteira
- Departamento de Biologia, Centro de Genética e Biologia Molecular, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, 45662-900, Brazil; Embrapa Mandioca e Fruticultura, Cruz das Almas, Bahia, 44380-000, Brazil.
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de Lemos RCC, da Costa Silva D, Flavia de Albuquerque Melo-de-Pinna G. A structural review of foliar glands in Passiflora L. (Passifloraceae). PLoS One 2017; 12:e0187905. [PMID: 29136029 PMCID: PMC5685584 DOI: 10.1371/journal.pone.0187905] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 10/28/2017] [Indexed: 11/18/2022] Open
Abstract
Extrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of formaldehyde-ethanol-acetic acid and stored in a 70% ethanol solution. For anatomical analyses, part of the material was embedded in Paraplast, longitudinally sectioned and double stained with safranin and astra blue. Scanning electron microscopy analysis was also carried out. To analyze the presence of sugars in the secretion of foliar glands, a glucose strip test was used. Based on the results of morphological, anatomical and glucose strip tests, the foliar secretory glands in Passiflora can be grouped into two categories: Type I glands, defined as nectaries, can be elevated or flattened, and can have a sugar content high enough to be detected by the glucose strip test analysis. Type II glands are elevated and did not show a positive reaction to the glucose strip test. From an anatomical viewpoint, glands characterized as extrafloral nectaries show a multistratified secretory epidermis, typically followed by two flat layers of nectariferous parenchyma with dense content. Internal to these layers, vascular bundles are immersed in the subsecretory parenchyma and terminate in phloem cells. On the other hand, type II glands show a single layer of elongated secretory epidermal cells. Internal to this single layer, parenchyma and vascular tissue with both phloem and xylem elements can be observed. The analyzed species show a wide diversity of gland shape and distribution, and the combined analysis of morphology, anatomy and preliminary tests for the presence of glucose in the exudate in different Passiflora subgenera suggests the occurrence of two categories of glands: nectaries and resin glands.
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Batista MEP, Silva DDC, Sales MAF, Sá AA, Saraiva AAF, Loiola MIB. New data on the stem and leaf anatomy of two conifers from the Lower Cretaceous of the Araripe Basin, northeastern Brazil, and their taxonomic and paleoecological implications. PLoS One 2017; 12:e0173090. [PMID: 28257466 PMCID: PMC5336239 DOI: 10.1371/journal.pone.0173090] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 02/15/2017] [Indexed: 11/19/2022] Open
Abstract
Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf anatomy of Pseudofrenelopsis sp. and B. obesum specimens is revisited, including the first report of some epidermal and vascular traits for both taxa from the Crato Formation. Along with its paleoecological significance, the new data suggest the presence of more than one Pseudofrenelopsis species in the Aptian taphoflora of the Araripe Basin and further support the taxonomic placement of B. obesum within Araucariaceae.
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Affiliation(s)
- Maria Edenilce Peixoto Batista
- Programa de Pós-Graduação em Ecologia e Recursos Naturais, Departamento de Biologia, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
- * E-mail:
| | - Delmira da Costa Silva
- Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Santa Cruz, Bahia, Brazil
| | - Marcos A. F. Sales
- Programa de Pós-Graduação em Geociências, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Artur A. Sá
- Departamento de Geologia, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal
- Centro de Geociências, Universidade de Coimbra, Coimbra, Portugal
| | - Antônio A. F. Saraiva
- Departamento de Ciências Biológicas, Universidade Regional do Cariri, Crato, Ceará, Brazil
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