In recent years salicylic acid (SA) has been the focus of intensive research due to its function as an endogenous signal mediating local and systemic plant defence responses against pathogens. It has ...also been found that SA plays a role during the plant response to abiotic stresses such as drought, chilling, heavy metal toxicity, heat, and osmotic stress. In this sense, SA appears to be, just like in mammals, an 'effective therapeutic agent' for plants. Besides this function during biotic and abiotic stress, SA plays a crucial role in the regulation of physiological and biochemical processes during the entire lifespan of the plant. The discovery of its targets and the understanding of its molecular modes of action in physiological processes could help in the dissection of the complex SA signalling network, confirming its important role in both plant health and disease. Here, the evidence that supports the role of SA during plant growth and development is reviewed by comparing experiments performed by exogenous application of SA with analysis of genotypes affected by SA levels and/or perception.
Biostimulants are natural organic compounds that can be applied to plants, so that they can modify plant physiology, stimulate growth and increase response to biotic and abiotic stresses. ...Biostimulants must have good solubility in suitable solvents. The research about the Effect of Centella (Centella asiatica (L.) Urb.) Extract with Several Types of Solvents as a Biostimulant on the Growth of Pagoda Mustard (Brassica rapa var. narinosa L.) was conducted from March to June 2022 at the Plant Physiology Laboratory and Greenhouse, Department of Biology, Faculty of Mathematics and Natural Sciences, Andalas University, Padang. The research aims to determine the effect of C. asiatica extract with several types of solvents as a biostimulant and to determine the best type of solvent to extract C. asiatica as a biostimulant in increasing the growth of Pagoda mustard. This study used a completely randomized design (CRD) consisting of 5 treatments with 6 replications. The treatment consist of control, distilled water, methanol, ethanol and acetone. The results obtained in this study were C. asiatica extract with several types of solvents gave significantly different effects on the parameters of leaf number, leaf area and leaf chlorophyll content. The results of this study indicate that methanol and ethanol are the best solvents for making C. asiatica extract as a biostimulant that can increase the growth of Pagoda mustard.
The COsub.2 fertilization effect (CFE) plays a crucial role in the amelioration of climate change. Many physiological and environmental factors, such as stand age, stand type, and site conditions, ...may affect the extent of the CFE. However, the relationship between the CFE and these factors remains elusive. In this study, we used the emerging gross primary production (GPP) remote sensing products, with GPP predicted using eddy covariance–light use efficiency models (EC-LUE GPP) based on satellite near-infrared reflectance of vegetation (NIRv GPP) and assessed with a random forest model to explore the CFE trends with stand age in a coniferous forest and a broad-leaved forest in Heilongjiang Province, China. We additionally compared the differences among the CFEs under different site conditions. The CFEs in coniferous forests and broad-leaved forests both showed a rapid increase in stands of 10 to 20 years of age, followed by a decline after reaching a maximum, with the rate of decline reducing with age. Eventually, CFE remained stable in stands near 100 years of age. However, the CFE in coniferous forests exhibited more extended periods of rapid increase and a higher maximum than in broad-leaved forests. Moreover, in this study, we used the site class index (SCI) to grade site conditions. The results demonstrate that the CFE differed significantly under different levels of site conditions, and these differences gradually decreased with age. The site with the highest SCI had fewer environmental restrictions on the CFE, and consequently, the CFE rate of decline was faster. Our results are of significance in understanding the CFE and adapting to future changes in atmospheric COsub.2 concentration.
First off the mark: early seed germination Weitbrecht, Karin; Müller, Kerstin; Leubner-Metzger, Gerhard
Journal of experimental botany,
06/2011, Letnik:
62, Številka:
10
Journal Article
Recenzirano
Most plant seeds are dispersed in a dry, mature state. If these seeds are non-dormant and the environmental conditions are favourable, they will pass through the complex process of germination. In ...this review, recent progress made with state-of-the-art techniques including genome-wide gene expression analyses that provided deeper insight into the early phase of seed germination, which includes imbibition and the subsequent plateau phase of water uptake in which metabolism is reactivated, is summarized. The physiological state of a seed is determined, at least in part, by the stored mRNAs that are translated upon imbibition. Very early upon imbibition massive transcriptome changes occur, which are regulated by ambient temperature, light conditions, and plant hormones. The hormones abscisic acid and gibberellins play a major role in regulating early seed germination. The early germination phase of Arabidopsis thaliana culminates in testa rupture, which is followed by the late germination phase and endosperm rupture. An integrated view on the early phase of seed germination is provided and it is shown that it is characterized by dynamic biomechanical changes together with very early alterations in transcript, protein, and hormone levels that set the stage for the later events. Early seed germination thereby contributes to seed and seedling performance important for plant establishment in the natural and agricultural ecosystem.
Coastal ecotones can disrupt natural conditions, yielding intricate ecological contexts where salinity plays a variable role. The aim of this study was to assess the salinity effect on three species ...representatives of semifixed dune (Crucianella maritima, Helianthemum caput-felis and Teucrium dunense). Field data were collected to assess plant cover in semifixed dunes, ecotone with other coastal habitats, and artificial Posidonia oceanica wracks. Soil samples were collected, and conductivity measured. Then, experimental exposure to salinity was conducted with 6 seawater (SW) treatments (Control, 6.25 % SW, 12.5 % SW, 25 % SW, 50 % SW, 100 % SW). Flowering, gas exchange, chlorophyll fluorescence and enzymatic antioxidant measurements were conducted after two months of exposure. In the field trial, species presence varied depending on the habitat and was null on P. oceanica. The relation between conductivity and species abundance showed moderate tolerance for the three species. For C. maritima this relation was variable depending on the habitat. Experimental data suggest moderate tolerance with stress occurring at 25 % SW onwards. Gas exchange response to salinity was similar among species, but more drastic reduction in assimilation rate and larger decrease in water use efficiency was observed for C. maritima. Instead, photoinhibition occurred in H. caput-felis and T. dunense but was absent in C. maritima likely related to the fact that H. caput-felis and T. dunense activated catalase and superoxide dismutase enzymes, while C. maritima showed activation of glutathione-related enzymes. Malondialdehyde (MDA) increased in C. maritma and decreased for the other species indicating a more complex involvement of MDA under stress conditions. Flowering response to salinity was overall more resilient in T. dunense. Our results, based on field conductivity data and measurements of physiological, antioxidant, and reproductive traits, delineate specific tolerance differences and strategies towards salinity for Mediterranean semifixed dune species.
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•Abundance varied with habitat ecotone, being null on Posidonia oceanica wracks•Consistent abundance with soil conductivity among ecotones, excluding C. maritima•Species tolerance to salinity exposure was moderate, with low photoinhibition.•Tolerance was defined based on reproductive and water use efficiency differences.•Different enzymatic pathways were activated between more and less tolerant species.
Polyploidy is generally not tolerated in animals, but is widespread in plant genomes and may result in extensive genetic redundancy. The fate of duplicated genes is poorly understood, both ...functionally and evolutionarily. Soybean (Glycine max L.) has undergone two separate polyploidy events (13 and 59 million years ago) that have resulted in 75% of its genes being present in multiple copies. It therefore constitutes a good model to study the impact of whole‐genome duplication on gene expression. Using RNA‐seq, we tested the functional fate of a set of approximately 18 000 duplicated genes. Across seven tissues tested, approximately 50% of paralogs were differentially expressed and thus had undergone expression sub‐functionalization. Based on gene ontology and expression data, our analysis also revealed that only a small proportion of the duplicated genes have been neo‐functionalized or non‐functionalized. In addition, duplicated genes were often found in collinear blocks, and several blocks of duplicated genes were co‐regulated, suggesting some type of epigenetic or positional regulation. We also found that transcription factors and ribosomal protein genes were differentially expressed in many tissues, suggesting that the main consequence of polyploidy in soybean may be at the regulatory level.
Dear Editor,
Transcription factors （TFs） are proteins that regulate the expression of target genes by binding to specific cis-elements in pro-moter regions. Transcriptional regulators （TRs） a）so ...regulate the expression of target genes; however, they operate indirectly via interaction with the basal transcription apparatus （e.g., TFs）, or by altering the accessibility of DNA to TFs via chromatin remodeling. Another type of regulatory proteins, protein kinases （PKs）,
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