Overexpression of GASA5 increases the sensitivity of Arabidopsis to heat stress

Author: Zhang, S.; Wang, X. Description: Basal thermotolerance is very important for plant growth and development when plants are subjected to heat stress. However, little is known about the functional mechanism of gibberellins (GAs) in the basal thermotolerance of plants. In the present work, we provide molecular evidence that a member of the gene family encoding the GA-stimulated Arabidopsis (GASA) peptides, namely GASA5, is involved in the regulation of seedling thermotolerance. The GASA5-overexpressing plants displayed a weak thermotolerance, with a faster cotyledon-yellowing rate, lower seedling-survival rate, and slower hypocotyl elongation,…

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Regulation of Arabidopsis thaliana Ku genes at different developmental stages under heat stress

Author: Liu, P.F.; Wang, Y.K.; Chang, W.C.; Chang, H.Y.; Pan, R.L. Description: Ku, a heterodimeric protein consisting of 70- and 80-kDa subunits, is involved in many cellular processes, such as DNA replication, cell cycle regulation and heat shock response. Moreover, the expression of Arabidopsis thaliana Ku genes (AtKu) is modulated by certain plant hormones through several signal transduction pathways. This study investigated how AtKu are regulated by heat stress. AtKu expression in 3-week-old young seedlings was down-regulated by heat stress in a time-dependent manner, as examined using real-time quantitative PCR,…

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Analysis of short-term changes in the Arabidopsis thaliana glycerolipidome in response to temperature and light

Author: Burgos, A.; Szymanski, J.; Seiwert, B.; Degenkolbe, T.; Hannah, M.A.; Giavalisco, P.; Willmitzer, L. Description: Although the influence of temperature, particularly cold, on lipid metabolism is well established, previous studies have focused on long-term responses and have largely ignored the influence of other interacting environmental factors. Here, we present a time-resolved analysis of the early responses of the glycerolipidome of Arabidopsis thaliana plants exposed to various temperatures (4, 21 and 32 degrees C) and light intensities (darkness, 75, 150 and 400 mumol m(-2) s(-1)), including selected combinations. Using a…

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Proteomic pattern-based analyses of light responses in Arabidopsis thaliana wild-type and photoreceptor mutants

Author: Kim, D.S.; Cho, D.S.; Park, W.-M.; Na, H.J.; Nam, H.G. Description: Light critically affects the physiology of plants. Using two-dimensional gel electrophoresis, we used a proteomics approach to analyze the responses of Arabidopsis thaliana to red (660 nm), far-red (730 nm) and blue (450 nm) light, which are utilized by type II and type I phytochromes, and blue light receptors, respectively. Under specific light treatments, the proteomic profiles of 49 protein spots exhibited over 1.8-fold difference in protein abundance, significant at p <0.05. Most of these proteins were metabolic…

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Effect of atmospheric CO2 on plant defense against leaf and root pathogens of Arabidopsis

Author: Zhou, Yeling; Van Leeuwen, Sanne K.; Pieterse, Corné M. J.; Bakker, Peter A. H. M.; Van Wees, Saskia C. M. Description: Climate change and the associated increase in atmospheric CO2 levels may affect the severity of plant diseases and threaten future crop yields. Here, we compared responses of the model plant Arabidopsis thaliana to leaf and root pathogens with hemi-biotrophic or necrotrophic infection strategies under pre-industrial, current, and future atmospheric CO2 conditions. Defenses against biotrophs are generally regulated by salicylic acid (SA) signaling, whereas jasmonic acid (JA) signaling controls…

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Effects of low and elevated CO2 partial pressure on growth and reproduction of Arabidopsis thaliana from different elevations

Author: Ward, J.K.; Strain, B.R. Description: Atmospheric CO2 partial pressure may have been as low as 18 Pa during the Pleistocene and is expected to increase from 35 to 70 Pa before the end of the next century. Low CO2 reduces the growth and reproduction of C3 plants, whereas elevated CO2 often increases growth and reproduction. Plants at high elevation are exposed to reduced CO2 partial pressure and may be better adapted to the low CO2 of the Pleistocene. We examined genotypes of Arabidopsis thaliana from different elevations for variation…

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Comparative salt tolerance analysis between Arabidopsis thaliana and Thellungiella halophila, with special emphasis on K(+)/Na(+) selectivity and proline accumulation

Author: Ghars, M.A.; Parre, E.; Debez, A.; Bordenave, M.; Richard, L.; Leport, L.; Bouchereau, A.; Savoure, A.; Abdelly, C. Description: The eco-physiology of salt tolerance, with an emphasis on K(+) nutrition and proline accumulation, was investigated in the halophyte Thellungiella halophila and in both wild type and eskimo-1 mutant of the glycophyte Arabidopsis thaliana, which differ in their proline accumulation capacity. Plants cultivated in inert sand were challenged for 3 weeks with up to 500mM NaCl. Low salinity significantly decreased A. thaliana growth, whereas growth restriction was significant only at…

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Identification of two phenotypes of Arabidopsis thaliana under in vitro salt stress conditions

Author: Ruiz Carrasco, K.B.; Baroni Fornasiero, R.; Tassoni, A.; Bagni, N. Description: This study describes two phenotypes of Arabidopsis thaliana (ecotype Columbia) developed in vitro under salt stress (75 mM NaCl). The phenotypes 01 and 02 appeared visibly distinguishable by rosette morphology and competence to produce flowers. Phenotype 01, sensible to salt stress, accumulated high quantities of Na+, showed a slight reduction in dry mass, and high protein and chlorophyll contents. Moreover, its anatomy exhibited some xeromorphic traits. Phenotype 02, clearly salt tolerant, showed a morphology similar to control plants,…

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Auxin redistribution modulates plastic development of root system architecture under salt stress in Arabidopsis thaliana

Author: Wang, Y.; Li, K.; Li, X. Description: Auxin plays an important role in the modulation of root system architecture. The effect of salinity on primary root growth has been extensively studied. However, how salinity affects lateral root development and its underlying molecular mechanisms is still unclear. Here, we report that high salt exposure suppresses lateral root initiation and organogenesis, resulting in the abortion of lateral root development. In contrast, salt stress markedly promotes lateral root elongation. Histochemical staining showed that the quantity of auxin and its patterning in roots…

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Role of plant RNA-binding proteins in development, stress response and genome organization

Author: Lorkovic, Z.J. Description: RNA-binding proteins (RBPs) in eukaryotes have crucial roles in all aspects of post-transcriptional gene regulation. They are important governors of diverse developmental processes by modulating expression of specific transcripts. The Arabidopsis (Arabidopsis thaliana) genome encodes for more than 200 different RBPs, most of which are plant specific and are therefore likely to perform plant-specific functions. Indeed, recent identification and analysis of plant RBPs clearly showed that, in addition to the important role in diverse developmental processes, they are also involved in adaptation of plants to various…

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