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Heredia-Guerrero J.A.,Italian Institute of Technology | Benitez J.J.,CSIC - Institute of Materials Science | Dominguez E.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Bayer I.S.,Italian Institute of Technology | And 4 more authors.
Frontiers in Plant Science | Year: 2014

The cuticle is one of the most important plant barriers. It is an external and continuous lipid membrane that covers the surface of epidermal cells and whose main function is to prevent the massive loss of water. The spectroscopic characterization of the plant cuticle and its components (cutin, cutan, waxes, polysaccharides and phenolics) by infrared and Raman spectroscopies has provided significant advances in the knowledge of the functional groups present in the cuticular matrix and on their structural role, interaction and macromolecular arrangement. Additionally, these spectroscopies have been used in the study of cuticle interaction with exogenous molecules, degradation, distribution of components within the cuticle matrix, changes during growth and development and characterization of fossil plants. © 2014 Heredia-Guerrero, Benítez, Domínguez, Bayer, Cingolani, Athanassiou and Heredia.


Lora J.,Institute Hortofruticultura Subtropical y Mediterranea la Mayora | Lora J.,Albert Ludwigs University of Freiburg | Herrero M.,CSIC - Aula Dei Experimental Station | Hormaza J.I.,Institute Hortofruticultura Subtropical y Mediterranea la Mayora
Sexual Plant Reproduction | Year: 2012

Pollen performance is an important determinant for fertilization success, but high variability in pollen behavior both between and within species occurs in different years and under varying environmental conditions. Annona cherimola, an early-divergent angiosperm, is a species that releases a variable ratio of bicellular and tricellular hydrated pollen at anther dehiscence depending on temperature. The presence of both bi- and tricellular types of pollen is an uncommon characteristic in angiosperms and makes Annona cherimola an interesting model to study the effect of varying environmental conditions on subsequent pollen performance during the final stages of pollen development. In this work, we study the influence of changes in temperature and humidity during the final stages of pollen development on subsequent pollen performance, evaluating pollen germination, presence of carbohydrates, number of nuclei, and water content. At 25 °C, which is the average field temperature during the flowering period of this species, pollen had a viability of 60-70 %, starch hydrolyzed just prior to shedding, and pollen mitosis II was taking place, resulting in a mixture of bi- and tricellular pollen. This activity may be related to the pollen retaining 70 % water content at shedding. Temperatures above 30 °C resulted in a decrease in pollen germination, whereas lower temperatures did not have a clear influence on pollen germination, although they did have a clear effect on starch hydrolysis. On the other hand, slightly higher dehydration accelerated mitosis II, whereas strong dehydration arrested starch hydrolysis and reduced pollen germination. These results show a significant influence of environmental conditions on myriad pollen characteristics during the final stages of pollen development modifying subsequent pollen behavior and contributing to our understanding of the variability observed in pollen tube performance. © 2012 Springer-Verlag.


Belliure B.,University of Alicante | Montserrat M.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Magalhaes S.,University of Lisbon
Acarologia | Year: 2010

Experimental evolution is a powerful tool to study the genetic and phenotypic changes in populations across generations and their potential causes. Due to their characteristics, mites represent an excellent group in which this methodology can be used. In this article, we review the literature on experimental evolution performed with mites as models. The studies we found focus on the evolution of host-plant selection, pesticide resistance, behavioral traits and sex-related traits. Overall, responses to selection were very rapid, and correlated responses on other traits were mostly absent or positive. We discuss the possible characteristics that make mites good models for experimental evolution studies and suggest future directions in the field. © 2009-2011 ACAROLOGIA.


Duressa D.,U.S. Department of Agriculture | Anchieta A.,U.S. Department of Agriculture | Chen D.,University of Alabama at Birmingham | Klimes A.,University of Western Ontario | And 6 more authors.
BMC Genomics | Year: 2013

Background: The soilborne fungus, Verticillium dahliae, causes Verticillium wilt disease in plants. Verticillium wilt is difficult to control since V. dahliae is capable of persisting in the soil for 10 to 15 years as melanized microsclerotia, rendering crop rotation strategies for disease control ineffective. Microsclerotia of V. dahliae overwinter and germinate to produce infectious hyphae that give rise to primary infections. Consequently, microsclerotia formation, maintenance, and germination are critically important processes in the disease cycle of V. dahliae.Results: To shed additional light on the molecular processes that contribute to microsclerotia biogenesis and melanin synthesis in V. dahliae, three replicate RNA-seq libraries were prepared from 10 day-old microsclerotia (MS)-producing cultures of V. dahliae, strain VdLs.17 (average = 52.23 million reads), and those not producing microsclerotia (NoMS, average = 50.58 million reads). Analyses of these libraries for differential gene expression revealed over 200 differentially expressed genes, including up-regulation of melanogenesis-associated genes tetrahydroxynaphthalene reductase (344-fold increase) and scytalone dehydratase (231-fold increase), and additional genes located in a 48.8 kilobase melanin biosynthetic gene cluster of strain VdLs.17. Nearly 50% of the genes identified as differentially expressed in the MS library encode hypothetical proteins. Additional comparative analyses of gene expression in V. dahliae, under growth conditions that promote or preclude microsclerotial development, were conducted using a microarray approach with RNA derived from V. dahliae strain Dvd-T5, and from the amicrosclerotial vdh1 strain. Differential expression of selected genes observed by RNA-seq or microarray analysis was confirmed using RT-qPCR or Northern hybridizations.Conclusion: Collectively, the data acquired from these investigations provide additional insight into gene expression and molecular processes that occur during MS biogenesis and maturation in V. dahliae. The identified gene products could therefore potentially represent new targets for disease control through prevention of survival structure development. © 2013 Duressa et al.; licensee BioMed Central Ltd.


Rodriguez-Lopez M.J.,Institute Ciencias Agrarias ICA | Rodriguez-Lopez M.J.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Garzo E.,Institute Ciencias Agrarias ICA | Bonani J.P.,Institute Ciencias Agrarias ICA | And 3 more authors.
PLoS ONE | Year: 2012

Background: The whitefly Bemisia tabaci (Genn.) causes dramatic damage to plants by transmitting yield-limiting virus diseases. Previous studies proved that the tomato breeding line ABL 14-8 was resistant to B. tabaci, the vector of tomato yellow leaf curl disease (TYLCD). This resistance is based on the presence of type IV glandular trichomes and acylsucrose production. These trichomes deter settling and probing of B. tabaci in ABL 14-8, which reduces primary and secondary spread of TYLCD. Methodology/Principal Findings: Whitefly settlement preference was evaluated on the adaxial and abaxial leaf surfaces of nearly-isogenic tomato lines with and without B. tabaci-resistance traits, 'ABL 14-8 and Moneymaker' respectively, under non-choice and free-choice conditions. In addition, the Electrical Penetration Graph technique was used to study probing and feeding activities of B. tabaci on the adaxial and abaxial leaf surfaces of the same genotypes. B. tabaci preferred to settle on the abaxial than on the adaxial surface of 'Moneymaker' leaves, whereas no such preference was observed on ABL 14-8 tomato plants at the ten-leaf growth stage. Furthermore, B. tabaci preferred to feed on the abaxial than on the adaxial leaf surface of 'Moneymarker' susceptible tomato plants as shown by a higher number of sustained phloem feeding ingestion events and a shorter time to reach the phloem. However, B. tabaci standard probing and feeding behavior patterns were altered in ABL 14-8 plants and whiteflies were unable to feed from the phloem and spent more time in non-probing activities when exposed to the abaxial leaf surface. Conclusions/Significance: The distorted behavior of B. tabaci on ABL 14-8 protects tomato plants from the transmission of phloem-restricted viruses such as Tomato yellow leaf curl virus (TYLCV), and forces whiteflies to feed on the adaxial side of leaves where they feed less efficiently and become more vulnerable to natural enemies. © 2012 Rodriguez-Lopez et al.


Friedman W.E.,Harvard University | Bachelier J.B.,Harvard University | Hormaza J.I.,Harvard University | Hormaza J.I.,Institute Hortofruticultura Subtropical y Mediterranea la Mayora
American Journal of Botany | Year: 2012

Premise of the study: Despite their highly reduced morphology, Hydatellaceae bear the unmistakable embryological signature of Nymphaeales, including a starch-rich maternal perisperm and a minute biparental endosperm and embryo. The co-occurrence of perisperm and endosperm in Nymphaeales and other lineages of flowering plants, and their respective functions during the course of seed development and embryo germination, remain enigmatic. • Methods: Development of the embryo, endosperm, and perisperm was examined histologically from fertilization through germination in flowers and fruits of Trithuria submersa. • Key results: The embryo of T. submersa initiates two cotyledons prior to seed maturity/dormancy, and their tips remain in contact with the endosperm throughout germination. The endosperm persists as a single layer of cells and serves as the interface between the embryo and the perisperm. The perisperm contains carbohydrates and proteins, and functions as the main storage tissue. The endosperm accumulates proteins and aleurone grains and functions as a transfer cell layer. • Conclusions: In Nymphaeales, the multiple roles of a more typical endosperm have been separated into two different tissues and genetic entities: a maternal perisperm (nutrient acquisition, storage, mobilization) and a minute biparental endosperm (nutrient transfer to the embryo). The presence of perisperms among several other ancient lineages of angiosperms suggests a modest degree of developmental and functional lability for the nutrient storage tissue (perisperm or endosperm) within seeds during the early evolution of flowering plants. Finally, we examine the evolutionary developmental hypothesis that, contrary to longstanding assumptions, an embryo-nourishing perisperm along with a minute endosperm may represent the plesiomorphic condition for flowering plants. © 2012 Botanical Society of America.


Matas I.M.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Lambertsen L.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Rodriguez-Moreno L.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Ramos C.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora
New Phytologist | Year: 2012

Comparative genomics and functional analysis of Pseudomonas syringae and related pathogens have mainly focused on diseases of herbaceous plants; however, there is a general lack of knowledge about the virulence and pathogenicity determinants required for infection of woody plants. Here, we applied signature-tagged mutagenesis (STM) to Pseudomonas savastanoi pv. savastanoi during colonization of olive (Olea europaea) knots, with the goal of identifying the range of genes linked to growth and symptom production in its plant host. A total of 58 different genes were identified, and most mutations resulted in hypovirulence in woody olive plants. Sequence analysis of STM mutations allowed us to identify metabolic pathways required for full fitness of P. savastanoi in olive and revealed novel mechanisms involved in the virulence of this pathogen, some of which are essential for full colonization of olive knots by the pathogen and for the lysis of host cells. This first application of STM to a P. syringae-like pathogen provides confirmation of functional capabilities long believed to play a role in the survival and virulence of this group of pathogens but not adequately tested before, and unravels novel factors not correlated previously with the virulence of other plant or animal bacterial pathogens. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.


Alcaraz M.L.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Hormaza J.I.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Rodrigo J.,CSIC - Centro de Investigación y Tecnología Agroalimentaria
Physiologia Plantarum | Year: 2010

In avocado, only a very small fraction of the flowers are able to set fruit. Previous work in other woody perennial plant species has shown the importance of carbohydrates accumulated in the flower in the reproductive process. Thus, in order to explore the implications of the nutritive status of the flower in the reproductive process in avocado, the starch content in the pistil has been examined in individual pollinated and non-pollinated flowers at anthesis and during the days following anthesis. Starch content in different pistilar tissues in each flower was quantified with the help of an image analysis system attached to a microscope. Flowers at anthesis were rich in highly compartmentalized starch. Although no external morphological differences could be observed among flowers, the starch content varied widely at flower opening. Starch content in the ovary is largely independent of flower size because these differences were not correlated with ovary size. Differences in the progress of starch accumulation within the ovule integuments between pollinated and non-pollinated flowers occurred concomitantly with the triggering of the progamic phase. The results suggest that starch reserves in the ovary could play a significant role in the reproductive process in avocado. © Physiologia Plantarum 2010.


Gross-German E.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora | Viruel M.A.,Institute Hortofruticultura Subtropical y Mediterranea La Mayora
Tree Genetics and Genomes | Year: 2013

Although molecular characterization of the avocado germplasm started with the early development of molecular markers, the genetic relationships among the three botanical races are still uncertain. Here, we report the development of 47 new microsatellites in avocado (Persea americana Mill) and the results of various genetic studies carefully designed to address the unsolved questions. Forty high-quality, single-locus markers (25 simple sequence repeats (SSRs) and 15 expressed sequence tag-SSRs (EST-SSRs)) were evaluated in a selected group of 42 cultivated accessions, which represent the three described botanical races. A total of 455 alleles (11. 4 alleles per locus) have been detected. The mean expected and observed heterozygosities averaged 0. 831 and 0. 674, respectively. All the analyzed genotypes could be unequivocally distinguished with an accumulated probability of identity value of 6. 36 × 10-50. Seventy-five percent of the loci showed a significant departure from Hardy-Weinberg equilibrium, most likely due to the substructure of the accession set and kinship among some of the accessions. The genetic relationships among the accessions were explored using different methods. We demonstrate that the correct allocation of the avocado cultivars requires the complementary use of distance-based and model-based methods. All of the results agreed with the existence of three groups to which accessions were assigned based on their botanical race, with 25 % of the detected variation being partitioned among the groups. The diversity analysis within each group has allowed for the identification of unique alleles that are useful as race-specific markers. The effects of the different experimental parameters on the results are discussed. © 2012 Springer-Verlag Berlin Heidelberg.


PubMed | Institute Hortofruticultura Subtropical y Mediterranea la Mayora and Laboratoire Daridoculture Et Cultures Oasiennes Institute Des Regions Arides Of Medenine
Type: | Journal: Hereditas | Year: 2017

The common fig (The results revealed that the 13 pairs of primers used amplified a total of 37 alleles in the accessions studied. The number of alleles per locus ranged from two to six, with a mean value of 2.85 alleles per locus. Observed and expected heterozygosities showed mean values of 0.33 and 0.29 respectively. UPGMA cluster analysis and Principal Component Analysis grouped the caprifig accessions analyzed in three groups.The results obtained show a low genetic diversity in the Tunisian accessions of caprifig studied and, in spite of analyzing samples from different geographic regions, no clear groupings based on geographical origin are observed suggesting widespread exchange of caprifig plant material through vegetative propagation among different areas in Tunisia.

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