2,406 research outputs found
Developmental signals in the 21st century; new tools and advances in plant signaling
No full textThis special issue includes different research papers and reviews that studied the role of signaling cascades controlling both plant developmental processes and plant response mechanisms to biotic and abiotic stresses [...]
Decoding hybridization barriers: the molecular and genetic orchestration of the triploid block in Arabidopsis thaliana
No full textPlant evolution has been greatly influenced by polyploidization phenomena. Polyploid plants yield more and are more resistant to unfavorable environments than their diploid relatives. The triploid block, a postzygotic barrier that causes failure of endosperm development and thus seed arrest, often prevents polyploid breeding. Alterations in the parental dose in interploidy crosses alter endosperm development by changing the correct maternal: paternal ratio (2m:1p) that this tissue requires to properly fulfill its proliferation and cellularization. After many years of research, the study of epigenetic regulation of gene expression during seed development has greatly increased our understanding of the triploid block. In plants, epigenetic regulation of genes has been shown to play a critical role in transcriptional control. This may be important for identifying novel and unexpected epigenetic mechanisms in the plant genome. Recent advances in understanding how epigenetic mechanisms control the expression of imprinted genes in seeds have contributed to understanding how different seed compartments interact at fertilization for successful seed formation. We here also review the potential role of maternally derived sporophytic tissues (seed coat) in the establishment of the triploid block. We also present a data analysis that includes spatiotemporal expression patterns of key genes involved in controlling hybridization barriers. This review provides an overview of the triploid block in plants, discussing how understanding its epigenetic regulation could offer new strategies to overcome hybridization barriers. We explore how these insights may enhance crop productivity and resilience
Carbohydrate reserves and seed development : an overview
No full textSeeds are one of the most important food sources, providing humans and animals with essential nutrients. These nutrients include carbohydrates, lipids, proteins, vitamins and minerals. Carbohydrates are one of the main energy sources for both plant and animal cells and play a fundamental role in seed development, human nutrition and the food industry. Many studies have focused on the molecular pathways that control carbohydrate flow during seed development in monocot and dicot species. For this reason, an overview of seed biodiversity focused on the multiple metabolic and physiological mechanisms that govern seed carbohydrate storage function in the plant kingdom is required. A large number of mutants affecting carbohydrate metabolism, which display defective seed development, are currently available for many plant species. The physiological, biochemical and biomolecular study of such mutants has led researchers to understand better how metabolism of carbohydrates works in plants and the critical role that these carbohydrates, and especially starch, play during seed development. In this review, we summarize and analyze the newest findings related to carbohydrate metabolism’s effects on seed development, pointing out key regulatory genes and enzymes that influence seed sugar import and metabolism. Our review also aims to provide guidelines for future research in the field and in this way to assist seed quality optimization by targeted genetic engineering and classical breeding programs
Evolutionary studies of the bHLH transcription factors belonging to MBW complex: their role in seed development
No full textBackground and aims: The MBW complex consist of proteins belonging to three major families MYB, bHLH and WDR, involved in various processes throughout plant development: epidermal cell development, mucilage secretory cells and flavonoid biosynthesis. Recently, it has been reported that TT8, encoding a bHLH transcription factor, is involved in the biosynthesis of flavonoids in the seed coat and it also plays a role in bypassing the postzygotic barrier resulting from an unbalance in genetic loads of the parental lines. Here we focus on the functional evolution, in seed development, of the bHLH proteins that are part of the MBW complex complemented with a literature review. Methods: Phylogenetic analyses performed across seed plants, and expression analyses in the reproductive tissues of four selected angiosperms: Arabidopsis thaliana, Brassica napus, Capsella rubella and Solanum lycopersicum, allowing us to hypothesize on the evolution of its functions. Key results: TT8 expression in the innermost layer of the seed coat is conserved in the selected angiosperms. However, except for Arabidopsis, TT8 is also expressed in ovules, carpels and fruits. The homologs belonging to TT8's sister clade, EGL3/GL3, involved in trichome development, are expressed in the outermost layer of the seed coat, suggesting potential roles in mucilage. Conclusions: The ancestral function of these genes appears to be flavonoid biosynthesis and the conservation of TT8 expression patterns in the innermost layer of the seed coat in angiosperms suggests that their function in postzygotic barriers may also be conserved. Moreover, the literature review and the results of the present study suggest a sophisticated association, linking the mechanisms of action of these genes to the cross-communication activity between the different tissues of the seed. Thus, it provides avenues to study the mechanisms of action of TT8, in the postzygotic triploid block, which is crucial since it impacts seed development in unbalanced crosses
Plant cell walls tackling climate change : insights into plant cell wall remodeling, its regulation, and biotechnological strategies to improve crop adaptations and photosynthesis in response to global warming
No full textPlant cell wall (CW) is a complex and intricate structure that performs several functions throughout the plant life cycle. The CW of plants is critical to the maintenance of cells’ structural integrity by resisting internal hydrostatic pressures, providing flexibility to support cell division and expansion during tissue differentiation, and acting as an environmental barrier that protects the cells in response to abiotic stress. Plant CW, comprised primarily of polysaccharides, represents the largest sink for photosynthetically fixed carbon, both in plants and in the biosphere. The CW structure is highly varied, not only between plant species but also among different organs, tissues, and cell types in the same organism. During the developmental processes, the main CW components, i.e., cellulose, pectins, hemicelluloses, and different types of CW-glycoproteins, interact constantly with each other and with the environment to maintain cell homeostasis. Differentiation processes are altered by positional effect and are also tightly linked to environmental changes, affecting CW both at the molecular and biochemical levels. The negative effect of climate change on the environment is multifaceted, from high temperatures, altered concentrations of greenhouse gases such as increasing CO2 in the atmosphere, soil salinity, and drought, to increasing frequency of extreme weather events taking place concomitantly, therefore, climate change affects crop productivity in multiple ways. Rising CO2 concentration in the atmosphere is expected to increase photosynthetic rates, especially at high temperatures and under water-limited conditions. This review aims to synthesize current knowledge regarding the effects of climate change on CW biogenesis and modification. We discuss specific cases in crops of interest carrying cell wall modifications that enhance tolerance to climate change-related stresses; from cereals such as rice, wheat, barley, or maize to dicots of interest such as brassica oilseed, cotton, soybean, tomato, or potato. This information could be used for the rational design of genetic engineering traits that aim to increase the stress tolerance in key crops. Future growing conditions expose plants to variable and extreme climate change factors, which negatively impact global agriculture, and therefore further research in this area is critical
MADS-box genes involved in the development of the reproductive structures of Nymphaea caerulea
No full textMolecular mechanisms of BASIC PENTACYSTEINE PROTEINS (BPCs) and the MADS-box factor SVP in the regulation of homeotic genes in Arabidopsis
No full textThe Arabidopsis transcription factor BPCs family is composed of seven members divided into three classes, based on their protein sequence similarity. BPCs bind the regulatory sequence of the homeotic gene SEEDSTICK (STK) promoter together with the MADS-box factor SHORT VEGETATIVE PHASE (SVP) . We show that MADS-box binding sites on the STK promoter region are necessary for STK correct spatial expression. To study the contribution of BPCs of class II to the regulation of the homeotic gene we generated the quintuple bpc12346 mutant. Through ChIP experiments, we found that SVP binds the genomic region of STK even in the absence of BPCs, whereas BPCs need SVP for the binding of the STK promoter. Besides, BPCs mutations affect STK expression in the flower. Moreover we analyzed the repressive trimethylation mark at Lys-27 in histone H3 in STK regulatory regions and we found that it’s reduced in bpc12346 mutant suggesting a direct role of chromatin modification in the regulation of STK expression mediated by BPCs. Our results provide insights into the molecular mechanisms that drive transcription regulation in plants and investigate the involvement of a protein complex in which BPCs and MADS-box might cooperate to regulate the expression of homeotic genes during development
Paco Ignacio Taibo II.
No full textEncyclopaedia entry on contemporary Mexican author Paco Ignacio Taibo II
The role of cytokinin receptors in Arabidopsis thaliana seed development and how they affect the metabolomic profile
No full textBased on expression, functional, and metabolomic analyses in the seeds of the single-receptor mutants, each receptor has a specific function during seed development. Their redundant roles during this process are difficult to assess; moreover, the impact they have on plant development must also be taken into account. In this study, we investigated the role of cytokinin receptors in Arabidopsis thaliana seed development and their impact on the metabolomic profile. Our findings reveal distinct expression patterns among them in the seed: AHK2 expression is not detected in seed tissues, AHK3 is expressed in embryo, endosperm, and peripheral endosperm, while AHK4/CRE1 expression is restricted to a few embryo cells. These patterns are consistent with the observed phenotypes where ahk3 exhibits more severe seed phenotypes such as delayed embryo development and increased seed and endosperm size. Metabolomic analyses showed that the receptors impact the abundance of metabolites, with a remarkably high concentration of tannins in ahk2 with respect to wild type seeds, while ahk3 mutant seeds have a very low amount of tannins but elevated levels of other compounds such as sinapoylated glucosinolates (GSLs), important for plant defense. The metabolic profile performed further supports a link between cytokinin and the regulation of secondary metabolites such as flavonoids and glucosinolates. Our results suggest that each cytokinin receptor independently contributes to this regulation, reflected in the distinct metabolic profiles of each mutant
Networks controlling seed size in Arabidopsis
No full textHuman and livestock nutrition is largely based on calories derived from seeds, in particular cereals and legumes. Unveiling the control of seed size is therefore of remarkable importance in the frame of developing new strategies for crop improvement. The networks controlling the development of the seed coat, the endosperm and the embryo, as well as their interplay, have been described in Arabidopsis thaliana. In this review, we provide a comprehensive description of the current knowledge regarding the molecular mechanisms controlling seed size in Arabidopsis.Key message: Overview of seed size control
- …
