Review: Nutrient loading of developing seeds

2007 ◽  
Vol 34 (4) ◽  
pp. 314 ◽  
Author(s):  
Wen-Hao Zhang ◽  
Yuchan Zhou ◽  
Katherine E. Dibley ◽  
Stephen D. Tyerman ◽  
Robert T. Furbank ◽  
...  
Keyword(s):  
Seed Development ◽  
Nutrient Loading ◽  
Water Movement ◽  
Calcium Signalling ◽  
Mineral Elements ◽  
Transition Elements ◽  
Species Dominance ◽  
Developing Seeds ◽  
Plant Reproductive Success ◽  
Symplasmic Domain

Interest in nutrient loading of seeds is fuelled by its central importance to plant reproductive success and human nutrition. Rates of nutrient loading, imported through the phloem, are regulated by transport and transfer processes located in sources (leaves, stems, reproductive structures), phloem pathway and seed sinks. During the early phases of seed development, most control is likely to be imposed by a low conductive pathway of differentiating phloem cells serving developing seeds. Following the onset of storage product accumulation by seeds, and, depending on nutrient species, dominance of path control gives way to regulation by processes located in sources (nitrogen, sulfur, minor minerals), phloem path (transition elements) or seed sinks (sugars and major mineral elements, such as potassium). Nutrients and accompanying water are imported into maternal seed tissues and unloaded from the conducting sieve elements into an extensive post-phloem symplasmic domain. Nutrients are released from this symplasmic domain into the seed apoplasm by poorly understood membrane transport mechanisms. As seed development progresses, increasing volumes of imported phloem water are recycled back to the parent plant by process(es) yet to be discovered. However, aquaporins concentrated in vascular and surrounding parenchyma cells of legume seed coats could provide a gated pathway of water movement in these tissues. Filial cells, abutting the maternal tissues, take up nutrients from the seed apoplasm by membrane proteins that include sucrose and amino acid/H+ symporters functioning in parallel with non-selective cation channels. Filial demand for nutrients, that comprise the major osmotic species, is integrated with their release and phloem import by a turgor-homeostat mechanism located in maternal seed tissues. It is speculated that turgors of maternal unloading cells are sensed by the cytoskeleton and transduced by calcium signalling cascades.

scholarly journals Transcriptome Profiling Reveals Spatial-temporal Dynamics of Gene Expression Essential for Soybean Seed Development

2020 ◽  
Author(s):  
Hengyou Zhang ◽  
Zhenbin Hu ◽  
Yuming Yang ◽  
Xiaoqian Liu ◽  
Haiyan Lv ◽  
...  
Keyword(s):  
Seed Development ◽  
Temporal Dynamics ◽  
Expression Patterns ◽  
Soybean Seed ◽  
Transcriptome Profiling ◽  
Transcript Abundance ◽  
Specific Gene ◽  
Oilseed Crop ◽  
Seed Formation ◽  
Developing Seeds

Abstract Background: Seeds are the economic basis of oilseed crops, especially for soybean, thus far the most widely cultivated oilseed crop worldwide. Seed development is accompanied with a multitude of diverse cellular processes and revealing the underlying regulatory activities is critical for seed improvement. Results: Here, we profiled transcriptomes of developing seeds (20, 25, 30, 40 days after flowering) representing key points of seed development from early to full development. We identified a set of highly-abundant genes and highlighted the importance of these genes to support nutrient accumulation and transcriptional regulation in developing seeds. We identified 8,925 differentially expressed genes that exhibited temporal expression patterns over the course and had expression specificities in distinct tissues including seeds and non-seed tissues (roots, stems, leaves). Genes with specificities to non-seed tissues have tissue-specialized roles while remain relatively low transcript abundance in developing seeds, exhibiting their supportive roles spatially for seed development. Co-expression network analysis identified several under-explored genes in soybean that bridge tissue-specific gene modules. Conclusions: Our study provides a global view of gene activities and biological processes critical for seed formation in soybean and prioritizes a set of genes for further study. The results shed insight into the mechanism controlling seed development and storage reserves.

scholarly journals Comparative Transcriptome Analysis of Developing Seeds and Silique Wall Reveals Dynamic Transcription Networks for Effective Oil Production in Brassica napus L.

2019 ◽  
Vol 20 (8) ◽  
pp. 1982 ◽  
Author(s):  
Muhammad Shahid ◽  
Guangqin Cai ◽  
Feng Zu ◽  
Qing Zhao ◽  
Muhammad Uzair Qasim ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Seed Development ◽  
Vegetable Oil ◽  
Oil Content ◽  
Seed Oil ◽  
Seed Oil Content ◽  
Oil Accumulation ◽  
Developing Seeds ◽  
Oil Biosynthesis ◽  
Oil Crops

Vegetable oil is an essential constituent of the human diet and renewable raw material for industrial applications. Enhancing oil production by increasing seed oil content in oil crops is the most viable, environmentally friendly, and sustainable approach to meet the continuous demand for the supply of vegetable oil globally. An in-depth understanding of the gene networks involved in oil biosynthesis during seed development is a prerequisite for breeding high-oil-content varieties. Rapeseed (Brassica napus) is one of the most important oil crops cultivated on multiple continents, contributing more than 15% of the world’s edible oil supply. To understand the phasic nature of oil biosynthesis and the dynamic regulation of key pathways for effective oil accumulation in B. napus, comparative transcriptomic profiling was performed with developing seeds and silique wall (SW) tissues of two contrasting inbred lines with ~13% difference in seed oil content. Differentially expressed genes (DEGs) between high- and low-oil content lines were identified across six key developmental stages, and gene enrichment analysis revealed that genes related to photosynthesis, metabolism, carbohydrates, lipids, phytohormones, transporters, and triacylglycerol and fatty acid synthesis tended to be upregulated in the high-oil-content line. Differentially regulated DEG patterns were revealed for the control of metabolite and photosynthate production in SW and oil biosynthesis and accumulation in seeds. Quantitative assays of carbohydrates and hormones during seed development together with gene expression profiling of relevant pathways revealed their fundamental effects on effective oil accumulation. Our results thus provide insights into the molecular basis of high seed oil content (SOC) and a new direction for developing high-SOC rapeseed and other oil crops.

scholarly journals MicroRNAs expression dynamics reveal post-transcriptional mechanisms regulating seed development in Phaseolus vulgaris L.

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
José Ricardo Parreira ◽  
Michela Cappuccio ◽  
Alma Balestrazzi ◽  
Pedro Fevereiro ◽  
Susana de Sousa Araújo
Keyword(s):  
Phaseolus Vulgaris ◽  
Seed Development ◽  
Developmental Stages ◽  
Production Systems ◽  
Expression Profiles ◽  
Target Prediction ◽  
Grain Legumes ◽  
Developing Seeds ◽  
Expression Of Genes ◽  
Post Transcriptional Regulation

AbstractThe knowledge on post-transcriptional regulation mechanisms implicated in seed development (SD) is still limited, particularly in one of the most consumed grain legumes, Phaseolus vulgaris L. We explore for the first time the miRNA expression dynamics in P. vulgaris developing seeds. Seventy-two known and 39 new miRNAs were found expressed in P. vulgaris developing seeds. Most of the miRNAs identified were more abundant at 10 and 40 days after anthesis, suggesting that late embryogenesis/early filling and desiccation were SD stages in which miRNA action is more pronounced. Degradome analysis and target prediction identified targets for 77 expressed miRNAs. While several known miRNAs were predicted to target HD-ZIP, ARF, SPL, and NF-Y transcription factors families, most of the predicted targets for new miRNAs encode for functional proteins. MiRNAs-targets expression profiles evidenced that these miRNAs could tune distinct seed developmental stages. MiRNAs more accumulated at early SD stages were implicated in regulating the end of embryogenesis, postponing the seed maturation program, storage compound synthesis and allocation. MiRNAs more accumulated at late SD stages could be implicated in seed quiescence, desiccation tolerance, and longevity with still uncovered roles in germination. The miRNAs herein described represent novel P. vulgaris resources with potential application in future biotechnological approaches to modulate the expression of genes implicated in legume seed traits with impact in horticultural production systems.

scholarly journals Transcriptome profiling reveals the spatial-temporal dynamics of gene expression essential for soybean seed development

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hengyou Zhang ◽  
Zhenbin Hu ◽  
Yuming Yang ◽  
Xiaoqian Liu ◽  
Haiyan Lv ◽  
...  
Keyword(s):  
Seed Development ◽  
Temporal Dynamics ◽  
Expression Patterns ◽  
Critical Time ◽  
Soybean Seed ◽  
Transcript Abundance ◽  
Specific Gene ◽  
Oilseed Crop ◽  
Seed Formation ◽  
Developing Seeds

Abstract Background Seeds are the economic basis of oilseed crops, especially soybeans, the most widely cultivated oilseed crop worldwide. Seed development is accompanied by a multitude of diverse cellular processes, and revealing the underlying regulatory activities is critical for seed improvement. Results In this study, we profiled the transcriptomes of developing seeds at 20, 25, 30, and 40 days after flowering (DAF), as these stages represent critical time points of seed development from early to full development. We identified a set of highly abundant genes and highlighted the importance of these genes in supporting nutrient accumulation and transcriptional regulation for seed development. We identified 8925 differentially expressed genes (DEGs) that exhibited temporal expression patterns over the course and expression specificities in distinct tissues, including seeds and nonseed tissues (roots, stems, and leaves). Genes specific to nonseed tissues might have tissue-associated roles, with relatively low transcript abundance in developing seeds, suggesting their spatially supportive roles in seed development. Coexpression network analysis identified several underexplored genes in soybeans that bridge tissue-specific gene modules. Conclusions Our study provides a global view of gene activities and biological processes critical for seed formation in soybeans and prioritizes a set of genes for further study. The results of this study help to elucidate the mechanism controlling seed development and storage reserves.

Two starch-branching-enzyme isoforms occur in different fractions of developing seeds of kidney bean

2001 ◽  
Vol 359 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Shigeki HAMADA ◽  
Kouichi NOZAKI ◽  
Hiroyuki ITO ◽  
Yasushi YOSHIMOTO ◽  
Hironori YOSHIDA ◽  
...  
Keyword(s):  
Seed Development ◽  
Blot Analysis ◽  
Kidney Bean ◽  
Kinetic Properties ◽  
Branching Enzyme ◽  
Starch Branching Enzyme ◽  
Recombinant Enzymes ◽  
Significant Similarity ◽  
Developing Seeds ◽  
Enzyme Isoforms

The nature and enzymic properties of starch-branching enzyme (SBE) are two of the dominant factors influencing the fine structure of starch. To understand the role of this enzyme's activity in the formation of starch in kidney bean (Phaseolus vulgaris L.), a study was undertaken to identify the major SBE sequences expressed during seed development and to characterize the enzymic properties of the coded recombinant enzymes. Two SBE cDNA species (designated pvsbe2 and pvsbe1) that displayed significant similarity (more than 70%) to other family A and B SBEs respectively were isolated. Northern blot analysis revealed that pvsbe1 and pvsbe2 were differentially expressed during seed development. pvsbe2 showed maximum steady-state transcript levels at the mid-stage of seed maturation, whereas pvsbe1 reached peak levels at a later stage. Western blot analysis with antisera raised against both recombinant proteins (rPvSBE1 and rPvSBE2) showed that these two SBEs were located in different amyloplast fractions of developing seeds of kidney bean. PvSBE2 was present in the soluble fraction, whereas PvSBE1 was associated with the starch granule fraction. The differences in location suggest that these two SBE isoenzymes have different roles in amylopectin synthesis in kidney bean seeds. rPvSBE1 and rPvSBE2 were purified from Escherichia coli and their kinetic properties were determined. The affinity of rPvSBE2 for amylose (Km 1.27mg/ml) was lower than that of rPvSBE1 (0.46mg/ml). The activity of rPvSBE2 was stimulated more than 3-fold in the presence of 0.3M citrate, whereas rPvSBE1 activity was not affected. The implications of the enzymic properties and the distribution of SBEs and amylopectin structure are discussed.

SEED DEVELOPMENT | Nutrient Loading of Seeds

2003 ◽  
pp. 1240-1249 ◽  
Author(s):  
J.W. Patrick ◽  
C.E. Offler ◽  
A.J.E. van Bel
Keyword(s):  
Seed Development ◽  
Nutrient Loading

scholarly journals Elemental composition of forest litters of cod-podzolic soils in trial areas of forest experimental dacha

2021 ◽  
Vol 2 (44) ◽  
pp. 25-25
Author(s):  
Alexander Saakian ◽  
◽  
Keyword(s):  
Elemental Composition ◽  
Forest Litter ◽  
Mineral Elements ◽  
Ash Content ◽  
Pine Forest ◽  
Transition Elements ◽  
Organic Part ◽  
Podzolic Soils ◽  
Hygroscopic Moisture ◽  
Weight Method

The object to study iselemental composition of lime and pine forests litter of mixed grasses. In average samples, ground up and sieved through a sieve with adiameter of 0.25 mm, we determined the following: the hygroscopic moisture by drying in a desiccator above P2O5, the ash content by weight method, C, H, N content on a CHNS –vario Microcube automatic analyzer, the elemental composition by X-ray fluorescence method on the ReSPECTanalyzer of substance composition.Compared to lime forest litter, the organic part of pine forest one contains more aromatic, depleted in nitrogen-containing groups and oxidized compounds. The ash content of lime forest litter is 11.46%, pine forest litter - 7.19%. The chemical composition of the litter mineral part is formed by two groups of elements: macroelements (Ca, Si, Al, Fe, Mn, Mg, K, P, S, Na, Cl), which content varies from 0.02-0.03 to 2.36-3.07 % and microelements (Zn, Cr, Sr, Cu, Ni, Pb, Rb, As, Hg) contained in amounts from 0.24-0.39 to 151-199 μg / g. In the lime and pine forest litter in forest experimental dacha, Ca and Si absolutely prevail, which account for more than 70% in totalsum of the macroelements. Zn, Cr, Sr account for 74% in the total microelementsin pine forest litter and for 82% in lime forest one. Moreover, the total mineral elements content in the lime forest litter is higher except for Ni, Pb and Mn. The data obtained can be used for environmental monitoring. Keywords: FOREST LITTER, LIME FOREST, PINEFOREST, ORGANOGEN ELEMENTS, MACROELEMENTS, MICROELEMENTS, TRANSITION ELEMENTS

Differential expression of genes during legume seed development

1986 ◽  
Vol 314 (1166) ◽  
pp. 367-384 ◽  
Keyword(s):  
Gene Expression ◽  
Seed Development ◽  
Seed Protein ◽  
Practical Significance ◽  
Specific Expression ◽  
Control Of Gene Expression ◽  
Developing Seeds ◽  
Expression Of Genes ◽  
Seed Protein Genes ◽  
Developmental Programme

The accumulation of certain proteins specific to those tissues in the developing seeds of legumes represents a system of academic and practical significance in the study of differential gene expression. Besides the simple distinction between ‘seed-specific’ and ‘non-seed-specific’ expression of genes, further controls are present in determining the level of expression of a particular gene, and the variations in its expression with cell type, developmental stage and environmental perturbation. There are also genetic factors that lead to variations in the expression of homologous genes between lines or species. Gene expression can be assayed at the levels of synthesis of specific proteins, level of mRNA species, and transcription of specific genes, and the results of all these assays lead to a broad correlation between events at the level of the gene and protein deposition in the developing seed. This correlation is strong at earlier stages of seed development, but is weaker at later stages. Evidence is presented that control of gene expression occurs both at transcription and by post-transcriptional processes. Seed protein genes have conserved sequences in their 5' flanking regions that are specific to gene families, and these are suggested to be involved in transcriptional control of the expression of these genes. Although such sequences are unlikely to be solely responsible for transcription control, there is no strong evidence for changes in DNA methylation or in chromatin conformation being causally related to expression of seed protein genes. Control of gene expression in developing seeds is considered in terms of a genetically determined, conserved developmental programme, the aim of which is to produce a viable embryo. This programme will allow considerable plasticity in gene expression within constraints prescribed by seed viability. Although it may be possible to understand the immediate controls of seed protein gene expression, present systems are not adequate to study the genes that control the developmental programme. More fundamental investigations will be assisted by mutants that possess altered seed development patterns.

scholarly journals Integrated microRNA and transcriptome profiling reveal key miRNA-mRNA interaction pairs associated with seed development in Tartary buckwheat (Fagopyrum tataricum)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hongyou Li ◽  
Hengling Meng ◽  
Xiaoqian Sun ◽  
Jiao Deng ◽  
Taoxiong Shi ◽  
...  
Keyword(s):  
Seed Development ◽  
Target Genes ◽  
Developmental Stages ◽  
Transcriptome Profiling ◽  
Mineral Elements ◽  
Endosperm Development ◽  
Tartary Buckwheat ◽  
Integrated Analysis ◽  
Fagopyrum Tataricum ◽  
Regulatory Pathways

Abstract Background Tartary buckwheat seed development is an extremely complex process involving many gene regulatory pathways. MicroRNAs (miRNAs) have been identified as the important negative regulators of gene expression and performed crucial regulatory roles in various plant biological processes. However, whether miRNAs participate in Tartary buckwheat seed development remains unexplored. Results In this study, we first identified 26 miRNA biosynthesis genes in the Tartary buckwheat genome and described their phylogeny and expression profiling. Then we performed small RNA (sRNA) sequencing for Tartary buckwheat seeds at three developmental stages to identify the miRNAs associated with seed development. In total, 230 miRNAs, including 101 conserved and 129 novel miRNAs, were first identified in Tartary buckwheat, and 3268 target genes were successfully predicted. Among these miRNAs, 76 exhibited differential expression during seed development, and 1534 target genes which correspond to 74 differentially expressed miRNAs (DEMs) were identified. Based on integrated analysis of DEMs and their targets expression, 65 miRNA-mRNA interaction pairs (25 DEMs corresponding to 65 target genes) were identified that exhibited significantly opposite expression during Tartary buckwheat seed development, and 6 of the miRNA-mRNA pairs were further verified by quantitative real-time polymerase chain reaction (qRT-PCR) and ligase-mediated rapid amplification of 5′ cDNA ends (5′-RLM-RACE). Functional annotation of the 65 target mRNAs showed that 56 miRNA-mRNA interaction pairs major involved in cell differentiation and proliferation, cell elongation, hormones response, organogenesis, embryo and endosperm development, seed size, mineral elements transport, and flavonoid biosynthesis, which indicated that they are the key miRNA-mRNA pairs for Tartary buckwheat seed development. Conclusions Our findings provided insights for the first time into miRNA-mediated regulatory pathways in Tartary buckwheat seed development and suggested that miRNAs play important role in Tartary buckwheat seed development. These findings will be help to study the roles and regulatory mechanism of miRNAs in Tartary buckwheat seed development.

Study of charge transfer in FeTi

1983 ◽  
Vol 41 ◽  
pp. 296-297
Author(s):  
J. Taft∅
Keyword(s):  
Charge Transfer ◽  
Charge Distribution ◽  
Electron Scattering ◽  
Periodic System ◽  
Electron Distribution ◽  
Scattering Amplitude ◽  
Transition Elements ◽  
Hartree Fock ◽  
Cscl Structure ◽  
The Right

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.

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