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19 páginas, 6 figuras, 2 tablas., Menadione sodium bisulphite (MSB) is a water-soluble derivative of vitamin K3, or menadione, and has been previously demonstrated to function as a plant defence activator against several pathogens in several plant species. However, there are no reports of the role of this vitamin in the induction of resistance in the plant model Arabidopsis thaliana. In the current study, we demonstrate that MSB induces resistance by priming in Arabidopsis against the virulent strain Pseudomonas syringae pv. tomato DC3000 (Pto) without inducing necrosis or visible damage. Changes in gene expression in response to 0.2 mm MSB were analysed in Arabidopsis at 3, 6 and 24 h post-treatment using microarray technology. In general, the treatment with MSB does not correlate with other publicly available data, thus MSB produces a unique molecular footprint. We observed 158 differentially regulated genes among all the possible trends. More up-regulated genes are included in categories such as 'response to stress' than the background, and the behaviour of these genes in different treatments confirms their role in response to biotic and abiotic stress. In addition, there is an over-representation of the G-box in their promoters. Some interesting functions are represented among the individual up-regulated genes, such as glutathione S-transferases, transcription factors (including putative regulators of the G-box) and cytochrome P450s. This work provides a wide insight into the molecular cues underlying the effect of MSB as a plant resistance inducer., This work was partially funded by an INVESCAN, S.L. grant (No.OTT2001438) to the CSIC and by a BIO2006-02168 grant of MICINN to PT. The microarrays were funded in part by the “Genome España” Foundation. MER was supported by a research contract (ID-TF-06/002) from the Consejería de Industria, Comercio y Nuevas Tecnologías (Gobierno de Canarias). The authors thank CajaCanarias for their research support. We also thank Lorena Perales for her help in performing the bacterial growth curves, Dr. Héctor Cabrera for his useful advice on writing the manuscript, the English translation service of the Universidad Politécnica de Valencia and Mrs. Pauline Agnew whose endeavoured to edit the English translation of this paper.

Fecha de solicitud: 26-02-2009.- Titular: Consejo Superior de Investigaciones Científicas (CSIC), Use of compositions containing menadione and/or water-soluble derivatives thereof for biostimulating the natural mechanisms of absorption and transport of Ca 2+ by the plant, first contributing to preventing disease of the fruit due to Ca 2+ deficiency, partly counteracting production losses due to this cause, and second, improving fruit resistance during handling and transport. These aqueous soloutions can contain Vitamin K3, soluble [menadione sodium bisulphite] or barely soluble [menadione nicotinamide bisulphite] derivatives, separately or jointly. Preferably they are applied by spraying of the above-ground part of the plant or via the irrigation system, and are optionally mixed with different additives, such as fertilizers, insecticides, nematocides, fungicides, bactericides and herbicides., Uso de las composiciones que contienen el menadione y/o derivados solubles en agua de eso para biostimulating los mecanismos naturales de la absorción y del transporte de CA 2+ por la planta, primero contribuyendo a evitar la enfermedad de la fruta debida a la deficiencia del CA 2+, en parte contrarrestando las pérdidas de la producción debidas a esta causa, y en segundo lugar, mejorando resistencia de la fruta durante la manipulación y el transporte. El bote acuoso de estos soloutions contiene la vitamina K3, soluble [bisulfito del sodio del menadione] o apenas los derivados del soluble [bisulfito del nicotinamida del menadione], por separado o en común. Preferiblemente ellos son aplicado rociando de la parte sobre el suelo de la planta o vía el sistema de riego, y el son mezclaron opcionalmente con los diferentes aditivos, tales como fertilizantes, los insecticidas, los nematocides, los fungicidas, los bactericidas y los herbicidas.

12 pages, 2 figures, 4 tables.-- PMID: 19102748 [PubMed].-- PMCID: PMC2629474., [Background] The elucidation of gene expression patterns leads to a better understanding of biological processes. Real-time quantitative RT-PCR has become the standard method for in-depth studies of gene expression. A biologically meaningful reporting of target mRNA quantities requires accurate and reliable normalization in order to identify real gene-specific variation. The purpose of normalization is to control several variables such as different amounts and quality of starting material, variable enzymatic efficiencies of retrotranscription from RNA to cDNA, or differences between tissues or cells in overall transcriptional activity. The validity of a housekeeping gene as endogenous control relies on the stability of its expression level across the sample panel being analysed. In the present report we describe the first systematic evaluation of potential internal controls during tomato development process to identify which are the most reliable for transcript quantification by real-time RT-PCR., [Results] In this study, we assess the expression stability of 7 traditional and 4 novel housekeeping genes in a set of 27 samples representing different tissues and organs of tomato plants at different developmental stages. First, we designed, tested and optimized amplification primers for real-time RT-PCR. Then, expression data from each candidate gene were evaluated with three complementary approaches based on different statistical procedures. Our analysis suggests that SGN-U314153 (CAC), SGN-U321250 (TIP41), SGN-U346908 ("Expressed") and SGN-U316474 (SAND) genes provide superior transcript normalization in tomato development studies. We recommend different combinations of these exceptionally stable housekeeping genes for suited normalization of different developmental series, including the complete tomato development process., [Conclusion] This work constitutes the first effort for the selection of optimal endogenous controls for quantitative real-time RT-PCR studies of gene expression during tomato development process. From our study a tool-kit of control genes emerges that outperform the traditional genes in terms of expression stability., This work was partially funded by an INVESCAN, S.L. grant (No. OTT2001438) to the CSIC. The first author was supported by a research contract (ID-TF-06/002) from the Consejería de Industria, Comercio y Nuevas Tecnologías (Gobierno de Canarias). The authors thank CajaCanarias for research support.

Resumen español p. 87. Abstract en inglés, frasncés y español, The beneficial effects of bacteria in the soil are knwn, but those of commercial bacterial products, to enhance plant growth, remain unsolved. Therefore, the effect of RET-FLO PX357, a commercial mixture of microorganisms in a liquid suspension, was studied and quantitied on banana crop. Materials an methods. A concentrated culture of this product was tested for 2 years in two commercial banana plantations in Tenerife (Canary Islands, Spain). Three treatments were used: a control Fenemiphos nematicide (15 Laha$), and RET-FLO PX357 (20 Laha$). Parasitic root nematode number, pseudostem circunference, time to flowering, and bunch hand and finger number were determined; root, leaf and soil contents were analysed. Results and discussion. RET-FLO PX357 decreased Helicotylenchus nematode number and, in some cases increases phosphorous calcium and iron levels in roots and leaves; it brought about the reduction of available soil sodium concentration and electrical conductance levels; in improves pseudostem circunference and number of fingers per hand while advancing flowering time. Conclusion. RET-FLO PX357 allows ecological and economical improvements, important to take into account when deciding to carry out a sustainable agriculture, Les effets bénéfiques des bactríes du sol sont connues, mais ceux de préparations bactériennes commerciales, sur la crissance des plants, ne le sont pas encore. L'effet du RET-FLO PX357, un mélange du commerce constitué de microorganismes en suspension dans un liquide, a done été étudié et quantifié en bananeraies. Matérial et méthodes. L'application d'une culture concentrée de oe produit a été testée, sur 2 ans, dans deux bananeraies de Tenerife (îles Canaries). Trois traitements ont été appliqués : un Témoin, une application avec du Fénamiphos (nématicide) à 15 L-ha$, et du RET-FLO PX257 à 20 L-ha$. Le nombre de nématodes parasites des racines, ainsi que la circonférence du pseudotrone, le temps de floraison et les nombres de mains et de doigts des régimes ont été déterminés ; la composition des racines, des feuilles et du sol a été analysée. Resiultats et discussion. Le RET-FLO PX357 a provoqué la diminution du nombre de nématodes du genre Helicotylenchus et, dans certains cas, l'augmentation de la teneur des racines et des feuilles en phosphore, calcium ou en fer ; il a provoqué la réduction de la teneur du sodium disponible dans le sol et la diminution de la conductance électrique ; il a amélioré la circonférence du pseudosterm et le nombre de doirts par main, tout en diminuant le temps de floraison. Conclusion. Le produit testé présente des avantages écologiques et économiques qui devront être pris en compte lors de la mise en place une agriculture durable., Se conocen los efectos beneficiosos que tienen las bacterias en el suelo, pero los de preparaciones bacterianas comerciales en el crecimiento de las plantas no se conocen aún. Se procedió pues, al estudio y la cuantificación del efecto del RET-FLO PX357, una mezcla comercial constituida de microorganismos en suspensión en un líquido, en los bananales. Material y métodos. La aplicación de un cultivo concentrado de este producto ha sido probada, durante dos años, en Tenerife (Islas Canarias). Se efectuaron tres tratamientos: uno testigo, una aplicación con Fenamiphos (nematicida) de 15 L-ha$ y una con RET-FLO PX357 de 20-I. ha$. Se determinó el número de nematodos parásitos del sistema radical así como el diámetro del seudotallo, el tiempo de floración y el número de manos y dedos por racimo. Se abnalizó la composición de las raíces, de las hojas y del suelo. Resultados y discusión. El RET-FLO PX357 provocó la disminución de los nematodos del género Helicotylanchus y, en algunos casos, el aumento del contenido de P.¡m Ca o Fe en las raíces y hojas; provocó la reducción de contenido de Na disponible en el suelo y la disminución de la conductancia eléctrica: incrementón el diámetro del sedotallo y el número de dedos por mano a la vez que reducía el tiempo de floración. Conclusión. El producto probado presenta una serie de ventajas ecológocas y económicas con las que habrá que contar para la puesta en marcha de una agricultura sostenible., Sincer thanks are to the Company EIBOL, S.A. for supporting this research

A study about available Cu and Zn contents and the influence of some soil properties on the availability of these micronutrients for crops has been carried out in most of the agricultural zones of the Island of Tenerife (Canary Islands). The mean Cu content was 4.75 mg L-$ (AAAc-EDTA extractable Cu), 22.13% of soil presented values considered as marginals (1-2 mg L-$ Cu), and 6% contained levels below the value estimated as critical (1 mg L-$ Cu). Only 3.64% of analyzed soils showed high Cu values (>17 mg L-" (DTPA extractable Zn), a value sensibly higher than that reported by an international study carried out by FAO Unesco, 6.4% of the soils were within the Zn deficient range (10 mg L-$) appeared in 12.35% of the soils. When the study was carried outby zones (north and south), the highest Cu and Zn contents were present in the northern zone (mean values: 6.69 mg L ' Cu and 7.08 mg L-' Zn). Various correlations between some soil parameters and the studied micronutrients were observed.

12 págs, 4 figs, 6 tabs., Soil reserves and available potassium in La Palma Island (Canary Islands) are studied from a chemical and geological stand point. Values of ΔF were calculated in the saturated soil paste as an index of available potassium. Depletion curves of soil potassium are studied for ΔF and K in meq/100 gr.

9 págs, 3 figs, 4 tabs., Six extraction methods are compared in a study of available K in soils of Tenerife and La Palma (Canary Islands). Among the extractants, the ammonium acetate gives always the highest correlation coefficients and levels of significance when compared with the rest of the methods used.