Analysis of a suppressive subtractive hybridization library of Alternaria alternata resistant to 2-propenyl isothiocyanate

AbstractBackgroundIsothiocyanates (ITCs) are natural products obtained from plants of the Brassicas family. They represent an environmentally friendly alternative for the control of phytopathogenic fungi. However, as it has been observed with synthetic fungicides, the possibility of inducing ITC-resistant strains is a major concern. It is, therefore, essential to understanding the molecular mechanisms of fungal resistance to ITCs. We analyzed a subtractive library containing 180 clones of an Alternaria alternata strain resistant to 2-propenyl ITC (2-pITC). After their sequencing, 141 expressed sequence tags (ESTs) were identified using the BlastX algorithm. The sequence assembly was carried out using CAP3 software; the functional annotation and metabolic pathways identification were performed using the Blast2GO program.ResultsThe bioinformatics analysis revealed 124 reads with similarities to proteins involved in transcriptional control, defense and stress pathways, cell wall integrity maintenance, detoxification, organization and cytoskeleton destabilization; exocytosis, transport, DNA damage control, ribosome maintenance, and RNA processing. In addition, transcripts corresponding to enzymes as oxidoreductases, transferases, hydrolases, lyases, and ligases, were detected. Degradation pathways for styrene, aminobenzoate, and toluene were induced, as well as the biosynthesis of phenylpropanoid and several types of N-glycan.ConclusionsThe fungal response showed that natural compounds could induce tolerance/resistance mechanisms in organisms in the same manner as synthetic chemical products. The response of A. alternata to the toxicity of 2-pITC is a sophisticated phenomenon including the induction of signaling cascades targeting a broad set of cellular processes. Whole-transcriptome approaches are needed to elucidate completely the fungal response to 2-pITC

The First Signal to Initiate Fruit Ripening is Generated in the Cuticle: An Hypothesis

The paradigm that has prevailed for a long time sustains that ethylene is the first signal that initiates fruit ripening. However, in this manuscript, we present the hypothesis that a signal generated from the cuticle induces the synthesis of ethylene, and therefore, it is the initial signal that triggers the fruit-ripening phenomena. Among the experimental evidence supporting the hypothesis, we can mention that cuticle components released during the plant pathogenic attack can induce the synthesis of ethylene in plants. Also, it has been found that in fungi, a cuticle component can activate a transcription factor by phosphorylation, which induces the transcription of a gene encoding a cutinase. Besides, studies with plant tissues experiencing a high rate of cell expansion have shown that there is a careful synchronization between the demand of cuticle components and biosynthesis, which suggests that the plant cell can sense the moment in which the fruit would stop growing by cell expansion, and initiate the ripening phenomena. In this chapter, experimental evidences supporting the physiological role of the fruit cuticle in the fruit ripening phenomena will be presented and reviewed with the goal to show a possible role of the fruit cuticle in the onset of fruit ripening

Molecular Biology, Composition and Physiological Functions of Cuticle Lipids in Fleshy Fruits

Fleshy fruits represent a valuable resource of economic and nutritional relevance for humanity. The plant cuticle is the external lipid layer covering the nonwoody aerial organs of land plants, and it is the first contact between fruits and the environment. It has been hypothesized that the cuticle plays a role in the development, ripening, quality, resistance to pathogen attack and postharvest shelf life of fleshy fruits. The cuticle’s structure and composition change in response to the fruit’s developmental stage, fruit physiology and different postharvest treatments. This review summarizes current information on the physiology and molecular mechanism of cuticle biosynthesis and composition changes during the development, ripening and postharvest stages of fleshy fruits. A discussion and analysis of studies regarding the relationship between cuticle composition, water loss reduction and maintaining fleshy fruits’ postharvest quality are presented. An overview of the molecular mechanism of cuticle biosynthesis and efforts to elucidate it in fleshy fruits is included. Enhancing our knowledge about cuticle biosynthesis mechanisms and identifying specific transcripts, proteins and lipids related to quality traits in fleshy fruits could contribute to the design of biotechnological strategies to improve the quality and postharvest shelf life of these important fruit crops

La cadena productiva de guanábana: una opción para el desarrollo económico en Compostela, Nayarit

Objective: Characterize Compostela’s Soursop Production Chain, describe the risks that represent areas of opportunity, and propose an Intervention Order that settled the critical control points that must be implemented to promote Mexican soursop on international markets. Methodology: The approach to calculate the optimal intervention order for the Soursop Production Chain was designed based on direct and indirect information sources and consisted of five phases. Results: Compostela’s SPC is made up of three primary links: production, processing, and marketing, involving actors for each specific task. High-risk weak points and Critical Control Points were identified. Implementing these Critical Control Points would significantly improve the Soursop Production Chain’s revenue. An intervention order designed to configure the Soursop Production Chain as a successful regional development option was built based on the relevance analysis of each Critical Control Point. Limitations: Available information regarding soursop production and post-harvest is relatively scarce. Gathering this type of information represents an area of opportunity that requires consulting the actors that make up the chain. Conclusions: Compostela’s soursop presence in international high value markets is limited by risks in the Soursop Production Chain. This fruit’s perishable nature stands out as the main risk, which is aggravated by phytosanitary risks, poor interlink coordination, outdated handling techniques, and poor storage and transportation infrastructure. A conservative estimate suggests that by implementing this Intervention Order, Soursop Production Chains’s profits would increase at least 175% in a short to medium term.Objetivo: caracterizar la cadena productiva de guanábana en el municipio de Compostela, Nayarit, México, y describir las áreas de oportunidad y sus riesgos para proponer un orden de intervención de esa cadena productiva que establezca los puntos críticos de control que deben implementarse para impulsar la comercialización de guanábana mexicana en el mercado internacional. Metodología: partiendo de fuentes de información directas e indirectas, se construyó una base metodológica que consta de cinco fases diseñadas para calcular el OI óptimo. Resultados: La Cadena Productiva de Guanábana de Compostela se compone de tres eslabones primarios: producción, procesamiento y comercialización, compuestos por actores que cumplen labores específicas. Se identificaron puntos débiles de alto riesgo, así como los Puntos de Control Críticos en la Cadena Productiva de la Guanábana. En base al análisis de relevancia de cada Punto Crítico de Control se construyó un Orden de Intervención diseñado para configurar a la Cadena Productiva de la Guanábana como una opción de desarrollo regional exitosa. Limitaciones: La información disponible del sistema productivo y poscosecha de la guanábana es relativamente escaza. Generar este tipo de información representa un área de oportunidad que requiere el acercamiento con los actores que conforman la cadena. Conclusiones: La presencia de guanábana de Compostela en mercados internacionales de alto valor se ve limitada por riesgos presentes en su cadena productiva. La naturaleza perecedera del fruto destaca como el riesgo principal, y se agrava por riesgos fitosanitarios, mala coordinación entre eslabones, técnicas de manejo desactualizadas e infraestructura de almacenamiento y transporte deficiente. Se estima que implementar el Orden de Intervención incrementaría las ganancias de la Cadena Productiva de la Guanábana al menos 175% en un corto a mediano plazo

Desarrollo de nuevas variedades de uva (Vitis vinifera L.) sin semilla mediante rescate de embriones

One of the main objectives of a grape breeding program is the development of seedless varieties. However, to achieve this it is necessary to combine the embryo rescue technique with classical genetics. The aim ofthis work was to develop hybrids from crosses with the following varieties of seedless grape: Perlette, Black Seedless, Crimson Seedless, Crispy, Flame, Superior, Princesa, Red Globe, Fiesta, Fresno and Thompson, used as father and mother. The experiment was conducted at the experimental field Costa ofHermosillo from the National Institute ofForestry, Agriculture and Livestock in 2009. 23 hybridizations were performed by pollinating flowers manually twice a day for three consecutive days. The berries were harvested at the beginning of veraison and taken to the laboratory where the surface was sterilized before isolating the seminal rudiment. The seminal rudiments were transferred to a culture medium where they were kept between 75 to 90 days; the rescued embryos from the seminal rudiments were transferred to an incubation medium for embryos. 3 163 berries were harvested from which 3 836 seminal rudiments were isolated. In 8.76% of rudiments, was possible to rescue embryos. From the rescued embryos, 32.14% developed seedlings, from which two were able to be transferred to a greenhouse. It is concluded that the use of classical genetics along with embryo rescue technique allows obtaining progeny ofhybrids with different varieties of seedless grapes.Uno de los objetivos principales de un programa de mejoramiento genético de uva es el desarrollo de variedades sin semilla. Sin embargo, para lograr esto se requiere combinar la técnica de rescate de embriones con la genética tradicional. El objetivo de este trabajo fue desarrollar híbridos de cruzas con las siguientes variedades de uva sin semilla: Perlette, Black Seedless, Crimson Seedless, Crispy, Flame, Superior, Princesa, Red Globe, Fiesta, Fresno y Thompson, utilizadas como padre y como madre. El experimento se realizó en el campo agrícola experimental Costa de Hermosillo del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias en el año 2009. Se realizaron 23 hibridaciones mediante la polinización de las flores manualmente dos veces al día durante tres días consecutivos. Las bayas fueron cosechadas al inicio del envero y trasladadas al laboratorio donde se esterilizaron superficialmente antes del aislamiento de los rudimentos seminales. Los rudimentos fueron transferidos a un medio de cultivo donde permanecieron entre 75 y 90 días y los embriones rescatados de los rudimentos transferidos a medio para incubación de embriones. Se cosecharon en total 3 163 bayas de las cuales se aislaron 3836 rudimentos seminales. En 8.76% de los rudimentos, fue posible rescatar embriones. De los embriones rescatados, 32.14% desarrollaron plántulas de las cuales fue posible transferir dos al invernadero. Se concluye que la utilización de la genética tradicional con apoyo del protocolo de rescate de embriones del presente trabajo permite la obtención de progenie de hibridaciones con diferentes variedades de uva sin semilla

Toward Understanding the Molecular Recognition of Fungal Chitin and Activation of the Plant Defense Mechanism in Horticultural Crops

Large volumes of fruit and vegetable production are lost during postharvest handling due to attacks by necrotrophic fungi. One of the promising alternatives proposed for the control of postharvest diseases is the induction of natural defense responses, which can be activated by recognizing molecules present in pathogens, such as chitin. Chitin is one of the most important components of the fungal cell wall and is recognized through plant membrane receptors. These receptors belong to the receptor-like kinase (RLK) family, which possesses a transmembrane domain and/or receptor-like protein (RLP) that requires binding to another RLK receptor to recognize chitin. In addition, these receptors have extracellular LysM motifs that participate in the perception of chitin oligosaccharides. These receptors have been widely studied in Arabidopsis thaliana (A. thaliana) and Oryza sativa (O. sativa); however, it is not clear how the molecular recognition and plant defense mechanisms of chitin oligosaccharides occur in other plant species or fruits. This review includes recent findings on the molecular recognition of chitin oligosaccharides and how they activate defense mechanisms in plants. In addition, we highlight some of the current advances in chitin perception in horticultural crops

Data on antioxidant activity in grapevine (Vitis vinifera L.) following cryopreservation by vitrification

Cryopreservation is used for the long-term conservation of plant genetic resources. This technique very often induces lethal injury or tissue damage. In this study, we measured indicators of viability and cell damage following cryopreservation and vitrification-cryopreservation in Vitis vinifera L. axillary buds cv. “Flame seedless” stored in liquid nitrogen (LN) for: three seconds, one hour, one day, one week and one month; after LN thawed at 38 °C for three minutes. The enzymatic activity of catalase (CAT) and superoxide dismutase (SOD), as well as the amount of malondialdehyde (MDA), total protein and viability were assayed

Efecto de los crioprotectores en la morfología y pérdida iónica en yemas axilares de vid cv. `Flame Seedless´ crioconservadas

The cryopreservation has revolutionized the field of biotechnology. Frozen in liquid nitrogen (LN) preserves long living cells. In this sense, in this paper were evaluated three conditions of cryopreservation based on vitrification of buds of grapevine. The buds were subjected to the PVS2, PVS3 and glycerol for 0-420 min, and submerged in LN for one hour. After the incubation time electrolyte leakage was determined as a viability measurement, and tissue damage was evaluated through stereoscopic observation. Based on the viability percentage the best preservation method was using PVS3 solution (30%) followed by glycerol (25%) and PVS2 (<10%). The images of the buds exposed to PVS3 shows no tissue damage unlike to PVS2 and glycerol, were not sufficient to preserve buds tissue. The results shown here suggest that using PVS3 as protocol can be considered for buds grapevine germplasm preservation.La crioconservación ha revolucionado el campo de la biotecnología. Congelar en nitrógeno líquido (NL) preserva células por largo tiempo. En ese sentido, en este trabajo se evaluaron tres condiciones de crioconservación basados en la vitrificación de yemas de vid. Las yemas fueron sometidas a PVS2, PVS3 y glicerol por 0-420 min, y colocadas en NL por una hora. De modo posterior a cada tiempo de incubación se cuantificó la pérdida de iones como medida de viabilidad y se evaluó el daño mediante observación en estereoscopio. Basados en el porcentaje de viabilidad el mejor método fue empleando PVS3 (30% viabilidad), seguido de glicerol (25%) y PVS2 (<10%). Las imágenes de las yemas expuestas a PVS3 no muestran daño en el tejido, a diferencia de PVS2 y glicerol, los cuales resultaron insuficientes para preservar el tejido. Estos resultados sugieren que el protocolo utilizando PVS3 puede ser considerado para la preservación de yemas de vid