Postharvest bunch rot disease in table grapes (Vitis vinifera L.). a latent threat in Sonora

[SPA] La identificación del agente causal de la pudrición de racimos de la vid en uva para mesa en Sonora, ha permanecido sin determinar por muchos años. Con el objetivo de identificar el agente causal de la pudrición de racimos de la vid (Vitis vinifera L.) para mesa y establecer su patogenicidad, se analizaron racimos de uva para mesa durante la cosecha y empaque, en viñedos de Hermosillo, Sonora. De los tejidos analizados se aisló un hongo, el cual se caracterizó morfológica y molecularmente mediante la prueba de PCR, que se identificó como Botrytis cinerea Pers.:Fr. La etiología de la pudrición de racimos de la vid, se confirmó mediante la inoculación artificial de suspensión de esporas del hongo en racimos de los cultivares Flame Seedless y Princess Seedless en las etapas de prefloración, floración y postfloración. El proceso infectivo del hongo se determinó mediante el seguimiento histológico, encontrándose que la germinación de las esporas y elongación de los tubos germinativos se produce de 48 a 72 horas después de la inoculación (DDI) y la infección a partir de las 96 horas DDI, en la porción basal de las bayas. Se determinó la actividad de la enzima quitinasa durante el proceso de infección, encontrándose que dicha enzima no se induce por la presencia de Botrytis en la baya. También se comprobó la infección latente de Botrytis en bayas de ambos cultivares, mediante la prueba de PCR: Se discuten los resultados y las implicaciones para el manejo de Botrytis durante la postcosecha en uva de mesa. [ENG] Identification of the causal agent of bunch rot disease in table grapes at the Sonoran Desert remained elusive for many years. To establish the nature of the pathogen, samples of grape clusters were taken during harvest and packing processes in vineyards from Hermosillo, Sonora, Mexico. A fungus was isolated, which was morphologically and molecularly characterized as Botrytis cinerea Pers.:Fr. To confirm the etiology of the bunch rot, artificial inoculations of B. cinerea were done in Flame Seedless and Princess Seedless cultivars during pre-bloom, full bloom and post-bloom stages. Cluster samples were taken and fixed at different time intervals for histological analysis. Spore germination and germ tube elongation occurred 48 and 72 h after inoculation (HAI) and the infection happened 96 HAI along the berry basal portion. Likewise, Botrytis infection occurs in spite of the dry and hot weather of Sonoran desert. Latent infection of Botrytis was verified in berries of both cultivars. This report shows the latency of B. cinerea during high-temperature weather and its availability for infection under milder conditions during post-harvest storage.Francisco J. Rivas-Santoyo recibió una beca doctoral de CONACYT, y agradece el apoyo suplementario de la Universidad de Sonora, CIAD, A. C., y del Instituto de Fitosanidad del Colegio de Postgraduados para la realización de esta investigación. R. Sotelo-Mundo agradece al proyecto 36928-B por apoyo a infraestructura y M. Islas-Osuna al proyecto 40466-Z, ambos otorgados por CONACYT. Así mismo, M. J. Yáñez-Morales hace patente su agradecimiento por el apoyo al proyecto CONACYT 38409-V. Se agradece el apoyo técnico a los M.C. Jesús Manuel García-Robles y M.C. Edgar Felipe Morán-Palacio y M.C. Nidia Caceres-Carrizosa

The ‘Tommy Atkins’ mango genome reveals candidate genes for fruit quality

Mango, Mangifera indica L., an important tropical fruit crop, is grown for its sweet and aromatic fruits. Past improvement of this species has predominantly relied on chance seedlings derived from over 1000 cultivars in the Indian sub-continent with a large variation for fruit size, yield, biotic and abiotic stress resistance, and fruit quality among other traits. Historically, mango has been an orphan crop with very limited molecular information. Only recently have molecular and genomics-based analyses enabled the creation of linkage maps, transcriptomes, and diversity analysis of large collections. Additionally, the combined analysis of genomic and phenotypic information is poised to improve mango breeding efficiency

Proteínas trasportadoras de fósforo de la familia PHT1 y su uso potencial en la agricultura moderna

La agricultura se ha globalizado por sus modernos avances orientados a producir más y mejores alimentos bajo un modelo de protección ambiental. Esta práctica se realiza en suelos con diferentes cantidades de nutrientes disponibles y se basa en el uso de fuentes minerales externas para satisfacer la demanda del cultivo. El fósforo (P) es un macroelemento que participa en funciones vitales de las plantas como la producción de adenosín trifosfato (ATP), formación de biomembranas y reacciones de señalización, entre otras. Las plantas utilizan estrategias fisio-morfológicas ante una deficiencia de Pque se manifiestan en síntomas característicos comodesarrollo deficiente, elongación de raíz,maduración precoz yreducción de la productividad del cultivocomo consecuencia. Para mantener la homeostasis celular, las plantas inducenla sobreproducción de proteínas de membrana con función transportadoras de fosfatoen los diferentes órganos. Estas proteínaspertenecen a la familia PHT1, presentan un transporte de tipo sin porteque facilita la introducción de fosfato inorgánico (Pi) desde la rizosfera y permiten satisfacer lademanda biológicadurante los procesos de señalización yenergía. Estructuralmenteestas proteínassonaltamente conservadas en plantas (monocotiledóneas y dicotiledóneas) y secaracterizan por poseer 12 dominios transmembranales, undominio conservado 2A0109 y tamaño aproximado de 520 aa. El objetivo de la presente revisión es situar en perspectiva el conocimiento actual delas proteínas transportadoras de fosfato PHT1, tomando de base los avances en modelos biológicospara mejorar los procesos productivos y lastécnicas de manejonutricional en los cultivos.Agriculture has been globalized by its modern advances aimed at producing more and better food under a model of environmental protection. This practice is carried out in soils with different amounts of available nutrients and is based on the use of external mineral sources to satisfy the demand of the crop. Phosphorus (P) is a macroelement that participates in vital functions of plants such as the production of adenosine triphosphate (ATP), biomembrane formation and signaling reactions, among others. The plants use physio-morphological strategies in the face of a deficiency of P that manifest themselves in characteristic symptoms such as deficient development, root elongation, early maturation and reduction of crop productivity as a consequence. To maintain cellular homeostasis, plants induce overproduction of membrane proteins with phosphate transporting function in different organs. These proteins belong to the PHT1family, they present a simport type transport that facilitates the introduction of inorganic phosphate (Pi) from the rhizosphere and allows to satisfy the biological demand during the signaling and energy processes. Structurally these proteins are highly conserved in plants (monocotyledonous and dicotyledonous) and are characterized by having 12 transmembrane domains, a conserved 2A0109 domain and an approximate size of 520 aa. The objective of this review is to put in perspective the current knowledge of PHT1phosphate transport proteins, taking as a basis the advances in biological models to improve the productive processes and the techniques of nutritional management in crop

RESEARCH ARTICLE - Recombinant expression of marine shrimp lysozyme in Escherichia coli

Shrimp Lysozyme (Lyz) is a key component of the antibacterial response as part of the innate defense in Crustacea; however, it has not been possible to purify this protein because of the very low amount present in the shrimp blood cells (hemocytes). In an effort to produce enough protein to study its function and biochemical properties we have overexpressed Lysozyme from marine shrimp (Penaeus vannamei) in E. coli. A bacterial protein expression system based on the T7 polymerase promoter was used. Although Lyz was produced as insoluble protein in inclusion bodies, its refolding led to an active protein with a yield of ~10%. Details of the protein recombinant expression techniques applied to this shrimp protein are presented

The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum

Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, over-expression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought