BackgroundPlant small heat shock proteins (sHsps) accumulate in response to various environmental stresses, including heat, drought, salt and oxidative stress. Numerous studies suggest a role for these proteins in stress tolerance by preventing stress-induced protein aggregation as well as by facilitating protein refolding by other chaperones. However, in vivo evidence for the involvement of sHsps in tolerance to different stress factors is still missing, mainly due to the lack of appropriate mutants in specific sHsp genes.ResultsIn this study we characterized the function of a sHsp in abiotic stress tolerance in the moss Physcomitrella patens, a model for primitive land plants. Using suppression subtractive hybridization, we isolated an abscisic acid-upregulated gene from P. patens encoding a 16.4 kDa cytosolic class II sHsp. PpHsp16.4 was also induced by salicylic acid, dithiothreitol (DTT) and by exposure to various stimuli, including osmotic and salt stress, but not by oxidative stress-inducing compounds. Expression of the gene was maintained upon stress relief, suggesting a role for this protein in the recovery stage. PpHsp16.4 is encoded by two identical genes arranged in tandem in the genome. Targeted disruption of both genes resulted in the inability of plants to recover from heat, salt and osmotic stress. In vivo localization studies revealed that PpHsp16.4 localized in cytosolic granules in the vicinity of chloroplasts under non stress conditions, suggesting possible distinct roles for this protein under stress and optimal growth.ConclusionsWe identified a member of the class II sHsp family that showed hormonal and abiotic stress gene regulation. Induction of the gene by DTT treatment suggests that damaged proteins may act as signals for the stress-induction of PpHsp16.4. The product of this gene was shown to localize in cytosolic granules near the chloroplasts, suggesting a role for the protein in association with these organelles. Our study provides the first direct genetic evidence for a role of a sHsp in osmotic and salt stress tolerance, and supports a function for this protein particularly during the stress recovery stage of P. patens.
Water is usually the main limiting factor for soybean productivity worldwide and yet advances in genetic improvement for drought resistance in this crop are still limited. In the present study, we investigated the physiological and molecular responses to drought in two soybean contrasting genotypes, a slow wilting N7001 and a drought sensitive TJS2049 cultivars. Measurements of stomatal conductance, carbon isotope ratios and accumulated dry matter showed that N7001 responds to drought by employing mechanisms resulting in a more efficient water use than TJS2049. To provide an insight into the molecular mechanisms that these cultivars employ to deal with water stress, their early and late transcriptional responses to drought were analyzed by suppression subtractive hybridization. A number of differentially regulated genes from N7001 were identified and their expression pattern was compared between in this genotype and TJS2049. Overall, the data set indicated that N7001 responds to drought earlier than TJ2049 by up-regulating a larger number of genes, most of them encoding proteins with regulatory and signaling functions. The data supports the idea that at least some of the phenotypic differences between slow wilting and drought sensitive plants may rely on the regulation of the level and timing of expression of specific genes. One of the genes that exhibited a marked N7001-specific drought induction profile encoded a eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a). GmeIFiso4G-1a is one of four members of this protein family in soybean, all of them sharing high sequence identity with each other. In silico analysis of GmeIFiso4G-1 promoter sequences suggested a possible functional specialization between distinct family members, which can attain differences at the transcriptional level. Conditional overexpression of GmeIFiso4G-1a in Arabidopsis conferred the transgenic plants increased tolerance to osmotic, salt, drought and low temperature stress, providing a strong experimental evidence for a direct association between a protein of this class and general abiotic stress tolerance mechanisms. Moreover, the results of this work reinforce the importance of the control of protein synthesis as a central mechanism of stress adaptation and opens up for new strategies for improving crop performance under stress.
The Bcl-2-associated athanogene (BAG) family is an evolutionarily conserved, multifunctional group of co-chaperones regulators that modulate a number of diverse processes. Plant BAG genes were identified to play an extensive role in processes of programmed cell death (PCD) ranging from growth and development to stress responses. In this study, we identified BAG genes from different photosynthetic organisms in order to gather evolutionary insights on these proteins followed by an in silico characterization of the BAG family in the bryophyte Physcomitrium patens. Ten putative PpBAGs harbouring a characteristic BAG domain were grouped into two subfamilies based on the presence of additional conserved domains and phylogenetic distances. Group I consisted of PpBAG4 and PpBAG5, containing an additional ubiquitin-like domain, and PpBAG10 with only the BAG domain. Group II consisted of PpBAG1-3 and PpBAG6-9, containing a calmodulin-binding IQ motif, a novel feature associated with plant BAG proteins. Interestingly, PpBAG9 exhibits an EF-Hand domain, not reported to date in this class of proteins. Caspase cleavage sites in PpBAG1, PpBAG3, PpBAG4-5 and PpBAG9 were predicted. In silico analysis of BAG genes revealed the presence of stress responsive elements, and a stress-regulated expression pattern which appears to be dependent on specifically organized promoter regulatory elements. According to our analyses, the present data suggest that some members of Physcomitrium patens BAG gene family may play a role in heat responses, autophagy, and pathogen immunity. Further studies are required to unveil the role of specific members of this gene family in PCD and stress responses in Physcomitrium patens.
RESUMEN:Las técnicas de fijación y conservación anatómica son realizadas habitualmente con soluciones que contienen formol, dado su bajo costo. Estas tienen varias desventajas como el olor irritante, rigidez, cambios de coloración de las estructuras, así como toxicidad con potencial cancerígeno, teratogénico y mutagénico para quien lo manipula. Por esto, es deseable utilizar soluciones sin formol. El objetivo de este trabajo fue comparar 2 métodos de conservación cadavérica, uno con formol (solución de Montevideo) y otro sin formol (método de Prives) utilizando la placenta humana como órgano experimental, evaluando sus parámetros macroscópicos. Se utilizaron 46 placentas humanas de partos normales y gestación a término. Las placentas fueron separadas en dos grupos (n=22 y n=24 respectivamente). El primer grupo de placentas fue perfundido con una solución con formol y el segundo grupo en una solución sin formol. Luego ambos grupos fueron sumergidos y mantenidos en sus soluciones respectivas por dos semanas y posteriormente retiradas dejándolas al aire a temperatura ambiente por 2 semanas más. Se analizaron las variables cuantitativas de peso y diámetro en cada una de las piezas, así como las variables cualitativas de consistencia, color, olor y crecimiento de micro/macro organismos. La recopilación de datos fue realizada previo al lavado, a los 14, 21 y 28 días. Los resultados mostraron que las placentas conservadas con el método de Prives presentaron mejor conservación en relación a su diámetro, consistencia, color y menor olor irritante en relación a las placentas tratadas con solución con formol. En ningún caso hubo crecimiento de micro o macroorganismos. En conclusión, emplear soluciones alternativas que sustituyan ventajosamente al formol como la fórmula de Prives conservan mejor las características macroscópicas de las placentas sin generar un olor irritante, deteniendo el proceso de descomposición.PALABRAS CLAVE: Placenta; Técnicas anatómicas; Solución fijadora; Formol; Libre de formol. INTRODUCCIÓNLas técnicas de fijación y conservación anatómica tienen como propósito hacer a los tejidos estables y protegerlos contra el deterioro. Estas técnicas han sido fundamentales para el estudio de la anatomía humana y veterinaria, utilizadas para tratar diversos órganos y visceras con fines didácticos, académicos y de investigación. Es por esto que a través de la historia se han buscando sustancias que mantengan, dentro de lo posible, el estado natural del cuerpo u órganos (Bustamente et al., 2007).Con el uso del formol, se produjo una innovación en las técnicas de fijación y conservación de piezas anatómi-cas, así como en la preparación de piezas para el estudio histológico. Sus propiedades de fijación y conservación, unidas a una rápida y fácil difusión tisular, hacen que en la actualidad se esté empleando como base de las innumerables fórmulas existentes para estos fines (Bustamante et al.). El formol comercial es una solución acuosa saturada (alrededor del 37 y 40%) del gas formaldehído, el que presenta ventajas...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.