Publications by authors named "Karina Gramacho"

Witches' broom disease (WBD) affects cocoa trees ( L.) and is caused by the fungus that grows in the apoplast in its biotrophic phase and later progresses into the tissues, causing serious losses in the production of cocoa beans. Therefore, the apoplast of can provide important defense responses during the interaction with .

View Article and Find Full Text PDF

The apoplast performs important functions in the plant, such as defense against stress, and compounds present form the apoplastic washing fluid (AWF). The fungus , the causal agent of witches' broom disease (WBD) in , initially colonizes the apoplast in its biotrophic phase. In this period, the fungus can remain for approximately 60 days, until it changes to its second phase, causing tissue death and consequently large loss in the production of beans.

View Article and Find Full Text PDF

The fungus secretes protein effectors that manipulate the physiology of the host plant, but few effectors of this fungus have had their functions confirmed. We performed functional characterization of a promising candidate effector of . The inoculation of rBASIDIN at 4 µmol L in the mesophyll of leaflets of caused symptoms of shriveling within 6 h without the presence of necrosis.

View Article and Find Full Text PDF

The viability of inoculum was evaluated during the microfermentation process of diseased and healthy pulp-seed masses and on a range of carrier materials: aluminum, cloth, glass, paper, plastic, raffia, and rubber tire. Fungal survival was assessed before the microfermentation (0 h) and every 24 to 96 h by the growth of colonies in potato-dextrose-agar (PDA) and sporulation in seed shells. Colonies of and sporulation on seed shells were observed from seeds not submitted to microfermentation.

View Article and Find Full Text PDF

Introduction: , the cocoa tree, is a target for pathogens, such as fungi from the genera , , , , among others. Some cacao pathogens are restricted to specific regions of the world, such as the (CSSV) in West African countries, while others are expanding geographically, such as in the Americas. is one of the most threatening cacao pathogens since it directly attacks the cacao pods driving a significant reduction in production, and therefore economic losses.

View Article and Find Full Text PDF

Cacao is a globally important crop with a long history of domestication and selective breeding. Despite the increased use of elite clones by cacao farmers, worldwide plantations are established mainly using hybrid progeny material derived from heterozygous parents, therefore displaying high tree-to-tree variability. The deliberate development of hybrids from advanced inbred lines produced by successive generations of self-pollination has not yet been fully considered in cacao breeding.

View Article and Find Full Text PDF

Protease inhibitors (PIs) are important biotechnological tools of interest in agriculture. Usually they are the first proteins to be activated in plant-induced resistance against pathogens. Therefore, the aim of this study was to characterize a Theobroma cacao trypsin inhibitor called TcTI.

View Article and Find Full Text PDF

Moniliophthora perniciosa is a basidiomycete responsible for the witches' broom disease in cacao (Theobroma cacao L.). Chitin synthase (CHS), chitinase (CHIT) and autophagy (ATG) genes have been associated to stress response preceding the formation of basidiocarp.

View Article and Find Full Text PDF

Background: Witches' broom disease (WBD) of cacao (Theobroma cacao L.), caused by Moniliophthora perniciosa, is the most important limiting factor for the cacao production in Brazil. Hence, the development of cacao genotypes with durable resistance is the key challenge for control the disease.

View Article and Find Full Text PDF

The surface of plants forms a defense barrier that directly inhibits the first point of contact of microorganisms with the host. To understand this defense mechanism in Moniliophthora perniciosa interaction with Theobroma cacao cv Catongo, the aim of this study was to compare the changes in protein expression in basidiospores of the fungus M. perniciosa in response the leaf water washes (LWW) of two contrasting cocoa varieties for resistance to witches' broom disease.

View Article and Find Full Text PDF

Background: Theobroma cacao L. (cacao) is a perennial tropical tree, endemic to rainforests of the Amazon Basin. Large populations of bacteria live on leaf surfaces and these phylloplane microorganisms can have important effects on plant health.

View Article and Find Full Text PDF
Article Synopsis
  • The greenback parrotfish, Scarus trispinosus, is the largest herbivorous fish in the Southwestern Atlantic and has been listed as endangered due to overexploitation.
  • This study aimed to assess the genetic structure of its populations along a 2000 km stretch of the NE Brazilian coast, using specific primers tested from a related species.
  • Results indicated higher genetic diversity in two areas near the Abrolhos Bank, while broader genetic homogeneity was observed across the region; however, subtle genetic differences were found when locations were grouped by latitude, suggesting a complex interaction of local admixture and larval dispersal.
View Article and Find Full Text PDF

Background: The hemibiotrophic pathogens Moniliophthora perniciosa (witches' broom disease) and Moniliophthora roreri (frosty pod rot disease) are among the most important pathogens of cacao. Moniliophthora perniciosa has a broad host range and infects a variety of meristematic tissues in cacao plants, whereas M. roreri infects only pods of Theobroma and Herrania genera.

View Article and Find Full Text PDF

Background: Moniliophthora perniciosa is a phytopathogenic fungus responsible for witches' broom disease of cacao trees (Theobroma cacao L.). Understanding the molecular events during germination of the pathogen may enable the development of strategies for disease control in these economically important plants.

View Article and Find Full Text PDF
Article Synopsis
  • Witches' broom, caused by the fungus Moniliophthora perniciosa, is the most significant disease affecting cocoa crops in Bahia, Brazil, and other regions, and while its germination process is crucial, basidiospore biology has been under-researched.
  • This study aimed to enhance methods for producing basidiospores for protein analysis, ultimately creating a proteomics map of ungerminated basidiospores and establishing a protein interaction network using Ustilago maydis as a reference.
  • Findings revealed a substantial range in basidiospore productivity, identified 178 proteins linked to essential biological functions, and highlighted significant roles of certain orthologous proteins in fungal development despite their lack of clustering
View Article and Find Full Text PDF

Legumains are cysteine proteases related to plant development, protein degradation, programmed cell death, and defense against pathogens. In this study, we have identified and characterized three legumains encoded by Theobroma cacao genome through in silico analyses, three-dimensional modeling, genetic expression pattern in different tissues and as a response to the inoculation of Moniliophthora perniciosa fungus. The three proteins were named TcLEG3, TcLEG6, and TcLEG9.

View Article and Find Full Text PDF

The interaction amongst papain-like cysteine-proteases (PLCP) and their substrates and inhibitors, such as cystatins, can be perceived as part of the molecular battlefield in plant-pathogen interaction. In cacao, four cystatins were identified and characterized by our group. We identified 448 proteases in cacao genome, whereof 134 were cysteine-proteases.

View Article and Find Full Text PDF

The phytopathogenic fungus Moniliophthora perniciosa (Stahel) Aime & Philips-Mora, causal agent of witches' broom disease of cocoa, causes countless damage to cocoa production in Brazil. Molecular studies have attempted to identify genes that play important roles in fungal survival and virulence. In this study, sequences deposited in the M.

View Article and Find Full Text PDF

Clonal genotypes resistant to fungal diseases are an important component of the cocoa production system in southeastern Bahia state (Brazil), so that technologies for faster production of stronger and healthier plantlets are highly desirable. In this study, the effects of inoculated bacterial endophytes isolated from healthy adult cacao plants on seedlings, and aspects related to inoculation methods, colonization patterns, and photosynthesis were investigated. Sequencing of 16S rRNA, hsp-60, and rpo-B genes placed the wild-type isolates within the species Enterobacter cloacae (isolates 341 and 344) and Bacillus subtilis (isolate 629).

View Article and Find Full Text PDF

Boto, a class II transposable element, was characterized in the Moniliophthora perniciosa genome. The Boto transposase is highly similar to plant PIF-like transposases that belong to the newest class II superfamily known as PIF/Harbinger. Although Boto shares characteristics with PIF-like elements, other characteristics, such as the transposase intron position, the position and direction of the second ORF, and the footprint, indicate that Boto belongs to a novel family of the PIF/Harbinger superfamily.

View Article and Find Full Text PDF

This study reports on expression analysis associated with molecular systems biology of cacao-Moniliophthora perniciosa interaction. Gene expression data were obtained for two cacao genotypes (TSH1188, resistant; Catongo, susceptible) challenged or not with the fungus M. perniciosa and collected at three time points through disease.

View Article and Find Full Text PDF

Theobroma cacao is an economically important tree of several tropical countries. Its genetic improvement is essential to provide protection against major diseases and improve chocolate quality. We discovered and mapped new expressed sequence tag-single nucleotide polymorphism (EST-SNP) and simple sequence repeat (SSR) markers and constructed a high-density genetic map.

View Article and Find Full Text PDF

In plant-pathogen interaction, the hydrogen peroxide (H₂O₂) may play a dual role: its accumulation inhibits the growth of biotrophic pathogens, while it could help the infection/colonization process of plant by necrotrophic pathogens. One of the possible pathways of H₂O production involves oxalic acid (Oxa) degradation by apoplastic oxalate oxidase. Here, we analyzed the production of H₂O₂, the presence of calcium oxalate (CaOx) crystals and the content of Oxa and ascorbic acid (Asa)--the main precursor of Oxa in plants--in susceptible and resistant cacao (Theobroma cacao L.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionmcl81pk97s7t8tcc8k0pfndid6v4if6v): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once