Abiotic Stress in Plants and Metabolic Responses

The vast metabolic diversity observed in plants is the direct result of continuous evolutionary processes. There are more than 200,000 known plant secondary metabolites, representing a vast reservoir of diverse functions. When the environment is adverse and plant growth is affected, metabolism is profoundly involved in signaling, physiological regulation, and defense responses. At the same time, in feedback, abiotic stresses affect the biosynthesis, concentration, transport, and storage of primary and secondary metabolites. Metabolic adjustments in response to abiotic stressors involve fine adjustments in amino acid, carbohydrate, and amine metabolic pathways. Proper activation of early metabolic responses helps cells restore chemical and energetic imbalances imposed by the stress and is crucial to acclimation and survival. Time-series experiments have revealed that metabolic activities respond to stress more quickly than transcriptional activities do. In order to study and map all the simultaneous metabolic responses and, more importantly, to link these responses to a specific abiotic stress, integrative and comprehensive analyses are required. Metabolomics is the systematic approach through which qualitative and quantitative analysis of a large number of metabolites is increasing our knowledge of how complex metabolic networks interact and how they are dynamically modified under stress adaptation and tolerance processes. A vast amount of research has been done using metabolomic approaches to (i) characterize metabolic responses to abiotic stress, (ii) to discover novel genes and annotate gene function, and, (iii) more recently, to identify metabolic quantitative trait loci. The integration of the collected metabolic data concerning abiotic stress responses is helping in the identification of tolerance traits that may be transferable to cultivated crop species. In this review, the diverse metabolic responses identified in plants so far are discussed. We also include recent advances in the study of plant metabolomes and metabolic fluxes with a focus on abiotic stress-tolerance trait interactions

Administration of royal jelly in estrus synchronization protocols for wool and hair sheep

Objetive: To know the most representative results of the use of royal jelly in reproductive protocols in wool and hair sheep,Desing/methodology/approach: A review of studies referenced in scientific databases published in the livestock sector was carried out. Results: In sheep, the administration of royal jelly in conjunction with reproductive management protocols improves the response to oestrus timing, oestrus onset time and duration, number of large follicles, ovulatory rate, and gestation rate. Study limitations/implications: Royal jelly is a substance that has beneficial effects on sheep reproductive variables, however the cost can be a limitation for its incorporation into the synchronization protocols, in addition to being necessary to elucidate the active metabolites that exert the action and the most effective route of administration.Findings/conclusions: Royal jelly can be an alternative to be incorporated in the estrous synchronization programs in sheep in order to replace some hormonal and without reducing reproductive variables.Objective: To assess the most relevant results on the usage of royal jelly in reproductive protocols of wool and hair sheep. Design/methodology/approach: A review of studies referenced and published in scientific databases regard the livestock sector. Results: In ewes, administration of “royal jelly” in addition to reproductive management protocols improves the response to estrus synchronization, time of onset and duration of estrus, number of large follicles, ovulatory rate and gestation rate. Study limitations/implications: Royal jelly is a substance with beneficial effects on reproductive variables in ewes; however, the cost may be a limitation for its incorporation in synchronization protocols. Additionally, it is necessary to clarify the active metabolites that exert the action and the most effective route of administration. Findings/conclusions: Royal jelly can be an alternative incorporated to estrus synchronization programs in ewes to substitute some hormones without decreasing reproductive variables

Antagonism of two ascomycetes against Phytophthora capsici Leonian, causing wilt of pepper (Capsicum annuum L.)

"En esta investigación se evaluó la actividad antagónica y protección de plántulas in vitro del ascomiceto Xylaria poitei, y la actividad antagónica de éste en combinación con un ascomiceto desconocido (AD) contra P. capsici, causante de la marchitez del chile. Xylaria poitei protegió plántulas de chile y permitió la sobrevivencia de un 58.3% de las plántulas, mientras que el oomiceto causó 100% de mortandad; además este hongo inhibió el crecimiento micelial de P. capsici hasta un 49.6% en uno de los experimentos donde se establecieron confrontaciones duales. En confrontaciones triples ambos ascomicetos incrementan ligeramente su inhibición a los 12 días de establecida la confrontación contra P. capsici; y aún mantienen la inhibición del oomiceto cuatro días después. Ambos ascomicetos estimulan o inhiben su crecimiento en alguna fecha de evaluación durante la confrontación entre ellos. El medio líquido papa dextrosa expuesto al crecimiento de X. poitei (filtrado) tiene baja actividad contra el crecimiento micelial de P. capsici. Los resultados anteriores indican que la actividad antagónica de ambos ascomicetos contra P. capsici se incrementa cuando ambos crecen en forma combinada respecto a las confrontaciones duales, y sugieren que la actividad antagónica de X. poitei es estimulada por la presencia del oomicete.""In this study we evaluated the antagonistic activity and protection of seedlings in vitro of the ascomycete Xylaria poitei, and its antagonistic activity in combination with an unknown ascomycete (AD) against P. capsici, the cause of wilt in pepper. Xylariapoitei protected pepper seedlings and allowed 58.3% survival of seedlings, while the oomycete caused 100% mortality, besides this fungus inhibited the mycelial growth of P. capsici up to 49.6% in one of the experiments where they settled dual confrontations. In triple confrontations both ascomycetes increase slightly their inhibition at 12 days of confortation against P. capsici, and still maintain the inhibition of the oomycete four days later. It was observed that both ascomycetes stimulare or inhibit each other growth at some time during the evaluation of confortation. The potato dextrose liquid medium exposed to the growth of X. poitei (filtrate) has low activity against the mycelial growth of P. capsici. The above results indicate that the antagonistic activity of both ascomycetes againstbP. capsici increases when they grow in combination with respect to the dual confrontations, and suggest that the antagonistic activity of X. poitei is stimulated by the presence of the oomycete.

Antagonismo de dos ascomicetos contra phytophthora capsici leonian, causante de la marchitez del chile (capsicum annuum l.)

En esta investigación se evaluó la actividad antagónica y protección de plántulas in vitro del ascomiceto Xylaria poitei, y la actividad antagónica de éste en combinación con un ascomiceto desconocido (AD) contra P. capsici, causante de la marchitez del chile. Xylaria poitei protegió plántulas de chile y permitió la sobrevivencia de un 58.3% de las plántulas, mientras que el oomiceto causó 100% de mortandad; además este hongo inhibió el crecimiento micelial de P. capsici hasta un 49.6% en uno de los experimentos donde se establecieron confrontaciones duales. En confrontaciones triples ambos ascomicetos incrementan ligeramente su inhibición a los 12 días de establecida la confrontación contra P. capsici; y aún mantienen la inhibición del oomiceto cuatro días después. Ambos ascomicetos estimulan o inhiben su crecimiento en alguna fecha de evaluación durante la confrontación entre ellos. El medio líquido papa dextrosa expuesto al crecimiento de X. poitei (filtrado) tiene baja actividad contra el crecimiento micelial de P. capsici. Los resultados anteriores indican que la actividad antagónica de ambos ascomicetos contra P. capsici se incrementa cuando ambos crecen en forma combinada respecto a las confrontaciones duales, y sugieren que la actividad antagónica de X. poitei es estimulada por la presencia del oomicete

UV-B radiation modifies the acclimation processes to drought or cadmium in wheat

Under natural conditions plants are often subjected to multiple stress factors. The main aim of the present work was to reveal how UV-B radiation affects acclimation to other abiotic stressors. Wheat seedlings grown under normal light conditions or normal light supplemented with UV-B radiation were exposed to drought or Cd stress and were screened for changes in the contents of salicylic acid and its putative precursor ortho-hydroxy-cinnamic acid, and in the activity of the key synthesis enzyme, phenylalanine ammonia lyase. Certain other protective mechanisms, such as antioxidant enzyme activities and polyamines, were also investigated. PEG treatment under UV-B radiation did not cause wilting, but resulted in more pronounced salicylic acid accumulation, which may provide protection against drought stress in wheat plants. In contrast, the high level of salicylic acid accumulation in Cd-treated plants was not further enhanced by UV-B stress, but resulted in pronounced oxidative stress and the activation of antioxidant systems and polyamine synthesis. Changes in the levels of phenolic compounds are accompanied by increased phenylalanine ammonia lyase activity in the roots, but not in the leaves. The similar pattern observed for stress-induced changes in salicylic acid and ortho-hydroxy-cinnamic acid contents suggested that salicylic acid may play a decisive role via ortho-hydroxy-cinnamic acid. The results indicated that UV-B radiation might have either a positive or negative impact under the same conditions in wheat, depending on the type of secondary abiotic stress factor. The protective or damaging effects observed may be related to changes in the levels of phenolic compounds

Un panorama del tema de los organismos genéticamente modificados: bondades y riesgos con las plantas transgénicas A panorama of the subject of the modified organisms geneticly: benefits and risks with transgenic plants

En la actualidad se ha agudizado a nivel mundial el debate sobre la utilización de los organismos genéticamente modificados (OGM), entre ellos las plantas transgénicas. Se observan posturas polarizadas: por un lado, se encuentran los que consideran que al tomar en cuenta la escasez de alimentos en muchas regiones del mundo, sobre todo en el hemisferio sur, donde la agricultura enfrenta un sinnúmero de problemas, la aplicación de la biotecnología en la producción de alimentos presenta un enorme potencial y es una alternativa necesaria; por otro, la postura ambientalista plantea una moratoria de varios años, o la negación al uso de estos avances científicos, en su lugar circunscribe a la agricultura orgánica, muy en boga en Inglaterra y otros países desarrollados. Esta revisión ofrece al lector una opinión sobre el significado de las plantas transgénicas, cómo se generan y algunos elementos básicos sobre los beneficios, no exentos de riesgos, que significa su implementación en la agricultura, y que de hecho ya se vienen explotando en varias regiones del mundo, incluyendo a México

Bacterias del suelo capaces de llevar DNA exógeno a células

En la naturaleza las plantas establecen interacción con infinidad de microorganismos, especialmente bacterias y hongos, interacciones que son particularmente abundantes en la raíz, órgano que sirve de anclaje al suelo para la absorción de agua y sales minerales

Abiotic stress response in plants: integrative genetic pathways and overlapping reactions between abiotic and biotic stress responses

In all ecosystems, plants continuously face environmental stress and consequently are forced to respond with defensive and adaptive strategies. These responses require the activation of several signaling pathways that induce expression of specific genes. An effective response requires that the biological system have the genetic background to support the necessary molecular players that permit the assembly of essential integrative genetic pathways. In the most complicated scenario, plants must contend against more than one abiotic stress, pest, or pathogen at the same time, forcing an integral and complete defense response to adjust plant physiology. Certain molecular players act as hubs or master regulators to integrate signals from The exclusive license for this PDF is limited to personal website use only. No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services. Saúl Fraire-Velázquez, Lenin Sánchez-Calderón et al. 134 different regulatory pathways activated by two or more types of abiotic stress or forms of biotic stress. Some defense and adaptive genes are transcriptionally regulated not only by a specific abiotic stress but also by biotic stress, exposing the existence of overlapping pathways. The genes shared between these networks appear to allow plants to prioritize their responses and ensure their survival by using their resources efficiently. The well-documented shared or convergence points in the response to abiotic and biotic stress in plants exhibit a superimposed complexity, as exemplified by induction of certain defense genes by biotic stress in presence only of a specific environmental condition (temperature and humidity). Interestingly, accumulating data strongly support the hypothesis that the convergence points between abiotic and biotic stress pathways also modulate the post-embryonic developmental program which is one of the most conspicuous adaptive strategies to cope with environmental stress. Pathogen attack or abiotic stresses such as nutrient scarcity alter cell division and cell differentiation processes, and consequently the plant architecture is modified. Plant growth regulators, such as auxins, cytokinins, ethylene, and jamonic acid, as well as reactive oxygen species, play crucial roles in the early steps of the convergence between these multiple stress signals. The advancement in powerful molecular tools, including transcriptome and proteome analysis, whole-genome sequencing, and bioinformatic studies are enabling disection of networks in abiotic and biotic signaling cascades and identification of the overlapping reactions and key factors that fulfill very important roles as integrative signals in plants

Conserved versatile master regulators in signalling pathways in response to stress in plants

From the first land plants to the complex gymnosperms and angiosperms of today, environmental conditions have forced plants to develop molecular strategies to surpass natural obstacles to growth and proliferation, and these genetic gains have been transmitted to the following generations. In this long natural process, novel and elaborate mechanisms have evolved to enable plants to cope with environmental limitations. Elements in many signalling cascades enable plants to sense different, multiple and simultaneous ambient cues. A group of versatile master regulators of gene expression control plant responses to stressing conditions. For crop breeding purposes, the task is to determine how to activate these key regulators to enable accurate and optimal reactions to common stresses. In this review, we discuss how plants sense biotic and abiotic stresses, how and which master regulators are implied in the responses to these stresses, their evolution in the life kingdoms, and the domains in these proteins that interact with other factors to lead to a proper and efficient plant response.En las plantas, desde las primeras especies terrestres hasta las complejas gimnospermas y angiospermas de la actualidad, las condiciones ambientales han forzado el desarrollo de estrategias moleculares para superar obstáculos naturales para crecer y proliferar, y estas ganancias genéticas han sido transmitidas a las generaciones subsiguientes. En este largo proceso natural, nuevos y elaborados mecanismos han evolucionado para permitir a las plantas luchar con las limitaciones ambientales. Elementos en muchas cascadas de señalización permiten a las plantas sensar diferentes, múltiples y simultáneas señales ambientales. Un grupo versátil de reguladores maestros que regulan la expresión génica, controla las respuestas de las plantas a las condiciones de estrés. Para propósitos de mejoramiento genético, la tarea es determinar como activar esos reguladores maestros, para habilitar las apropiadas y óptimas reacciones a diferentes formas de estreses comunes en el medio ambiente. En esta revisión, se discute como las plantas sensan el estrés biótico y abiótico, y como y cuales reguladores maestros están implicados en las respuestas a estos estreses, su evolución en los reinos de la vida, así como los dominios en esas proteínas que interactúan con otros factores que conducen a la apropiada y eficiente respuesta de defensa en la planta