scholarly journals Female gametogenesis and early seed development in Amaranthus hypochondriacus L.

2018 ◽  
Vol 96 (3) ◽  
pp. 383
Author(s):  
Angelica Barrales-López ◽  
Lorenzo Guevara-Olvera ◽  
Eduardo Espitia-Rangel ◽  
Mario M. González-Chavira ◽  
Aurea Bernardino-Nicanor ◽  
...  
Keyword(s):  
Seed Development ◽  
Female Gametophyte ◽  
Seed Quality ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Seed Proteins ◽  
Amaranthus Hypochondriacus ◽  
Type Pattern ◽  
Functional Megaspore ◽  
Female Gametogenesis

<p><strong>Background</strong>: Attention to amaranth grains has increased in recent years due to the nutritional value of their seed proteins, which have high levels of the amino acid lysine. However, there is no detailed study describing the stages of seed development in <em>Amaranthus hypochondriacus. </em></p><p><strong>Question</strong>: How are the developmental patterns of the female gametophyte and young seed in <em>Amaranthus hypochondriacus</em>?</p><p><strong>Species studied</strong>: <em>Amaranthus hypochondriacus</em> L ’Revancha’ (Amaranthaceae).</p><p><strong>Study site and years of study</strong>: Plants were growth and collected from 2014 to 2016, in a greenhouse at Instituto Tecnológico de Celaya, Guanajuato, Mexico.</p><p><strong>Methods: </strong>Glomerules were collected before pollination and two weeks after anthesis. The ovules at different development stages were fixed and cleared and were analyzed by light microscopy. A clearing protocol was used to observe the developmental stages during female gametogenesis and embryogenesis.</p><p><strong>Results: </strong>We observed that the <em>Amaranthus hypochondriacus</em> ovule has a campylotropous form. The female gametophyte showed a<em> Polygonum</em>-type pattern of development. We were also able to identify all the stages from the megaspore mother cell to the cotyledon embryo stage. After meiosis, the micropylar megaspore differentiates into the functional megaspore. The embryo did not show symmetric divisions, although the final pattern is similar to that of in eudicotyledons. The suspensor showed additional longitudinal divisions, giving rise to a 2-rowed suspensor, while the endosperm showed a helobial development.</p><p><strong>Conclusions: </strong>These results will be used as baseline to identify morphological changes during seed development and to develop new strategies to improve seed quality or increase the yield.</p>

scholarly journals Gene expression profiling identifies pathways involved in seeds maturation of Jatropha curcas

2019 ◽  
Author(s):  
Fatemeh Maghuly ◽  
Tamas Deak ◽  
Klemens Vierlinger ◽  
Stephan Pabinger ◽  
Hakim Tafer ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Seed Development ◽  
Jatropha Curcas ◽  
Molecular Mechanisms ◽  
Seed Quality ◽  
Developmental Stages ◽  
Seed Maturation ◽  
Nutrient Mobilization ◽  
Starting Point ◽  
Maturation Stages

Abstract Background: Jatropha curcas, a tropical shrub, is a promising biofuel crop, which produces seeds with a high content of oil and protein. To better understand the development of its seeds to improve Jatropha`s agronomic performance, a two-step approach was performed: 1) generation of the entire transcriptome of six different maturation stages of J. curcas seeds using 454-Roche sequencing of a cDNA library, 2) comparison of transcriptional expression levels in six different developmental stages of seeds using a custom Agilent 8x60K oligonucleotide microarray. Results: A total of 793,875 high-quality reads were assembled into 19,841 unique full-length contigs, of which 13,705 could be annotated with Gene Ontology (GO) terms. Microarray data analysis identified 9,111 probes (out of 57,842 probes), which were differentially expressed between the six developmental stages. The expression results were validated for 70 randomly selected putative genes. Result from cluster analyses showed that transcripts related to sucrose, fatty acid, flavonoid, phenylpropanoid, lignin, hormone biosynthesis were over-represented in the early stage, while lipid storage, seed dormancy and maturation in the late stage. Generally, the expression of the most over-represented transcripts decrease in the last stage of seed maturation. Further, expression analyses of different maturation stages of J. curcas seed showed that most changes in transcript abundance occurred between the two last stages, suggesting that the timing of metabolic pathways during seed maturation in J. curcas is in late stages. The co-expression result showed a high degree of connectivity between genes that play essential role in fatty acid biosynthesis and nutrient mobilization. Furthermore, seed development and hormone pathways are significantly well connected. Conclusion: The obtained results revealed DESs regulating important pathways related to seed maturation, which could contribute to understanding the complex regulatory network during seed development. This study provides detailed information on transcription changes during J. curcas seed development and provides a starting point for a genomic survey of seed quality traits. The current results highlighted specific genes and processes relevant to the molecular mechanisms involved in Jatropha seed development, and it is anticipated that this data can be delivered to other Euphorbiaceae species of economic value.

scholarly journals SANe: The Seed Active Network for Discovering Transcriptional Regulatory Programs of Seed Development

2017 ◽  
Author(s):  
Chirag Gupta ◽  
Arjun Krishnan ◽  
Andrew Schneider ◽  
Cynthia Denbow ◽  
Eva Collakova ◽  
...  
Keyword(s):  
Seed Development ◽  
Regulatory Network ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Active Network ◽  
Transcriptional Regulatory ◽  
A Genome ◽  
Differential Network ◽  
Genome Scale ◽  
New Hypothesis

AbstractDeveloping seeds undergo coordinated physiological and morphological changes crucial for development of the embryo, dormancy and germination. The metabolic changes that occur during seed development are regulated by interconnected network of Transcription Factors (TFs) that regulate gene expression in a spatiotemporal manner. The complexity of these networks is such that the TFs that play key regulatory roles during seed development are largely unknown. In this study, we created a genome-scale regulatory network dedicated to describing regulation of biological processes within various compartments and developmental stages of Arabidopsis seeds. Differential network analysis revealed key TFs that rewire their targeting patterns specifically during seed development, many of which were already known, and a few novel ones that we verified experimentally. Our method shows that a high-resolution tissue-specific transcriptome dataset can be accurately modeled as a functional regulatory network predictive of related TFs. We provide an easy to use webtool using which researchers can upload a newly generated transcriptome and identify key TFs important to their dataset as well as gauge their regulatory effect on phenotypes observed in the experiment. We refer to this network as Seed Active Network (SANe) and made it accessible athttps://plantstress-pereira.uark.edu/SANe/. We anticipate SANe will facilitate the discovery of TFs yet unknown for their involvement in seed related metabolic pathways and provide an interface to generate new hypothesis for experimentation.

Acquisition of desiccation tolerance during seed development is associated with oxidative processes in rice

Botany ◽  
2016 ◽  
Vol 94 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Yongqi He ◽  
Jinping Cheng ◽  
Xiaodan Li ◽  
Peng Zeng ◽  
Bin Yang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Seed Quality ◽  
Developmental Stages ◽  
Oryza Sativa L ◽  
Rice Seed ◽  
Sod Activity ◽  
Oxidative Processes ◽  
Germination Traits

Desiccation tolerance is an important characteristic of rice seed quality during seed drying. In this study, two varieties of Oryza sativa L. subsp. japonica (Jiucaiqing and Wuyunjing 7) were used to investigate the dynamic changes in rice seeds that are associated with desiccation tolerance (germination traits produced by dried seeds), grain mass (GW), moisture content (MC), and electrical conductivity (EC) during seed development (18 to 42 days after heading (DAH)). Changes in the levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in fresh, dry, and imbibed states, and antioxidant enzyme activity (superoxide dismutase (SOD); catalase (CAT); and glutathione reductase (GR)) in fresh and imbibed seeds were also evaluated during seed development. The results showed that seeds started to acquire desiccation tolerance at 26 DAH and reached the highest levels at 38 DAH. The increase in GW and decline in MC coincided with the acquisition of desiccation tolerance. MDA and H2O2 levels, and SOD, CAT, and GR activities in fresh and imbibed seeds rapidly decreased during the early developmental stages (18–30 DAH), and then their levels gradually stabilized (30–42 DAH). Regression analyses indicated that H2O2 levels in fresh seeds was negatively correlated with seed germination, whereas SOD activity in imbibed seeds was positively correlated with seed germination. H2O2 and SOD are, therefore, good parameters for assessing desiccation tolerance during rice seed development.

LIPID AND MORPHOLOGICAL CHANGES IN DEVELOPING RAPESEED, BRASSICA NAPUS

1970 ◽  
Vol 50 (3) ◽  
pp. 233-247 ◽  
Author(s):  
D. B. FOWLER ◽  
R. K. DOWNEY
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Brassica Napus ◽  
Erucic Acid ◽  
Seed Development ◽  
Acid Composition ◽  
Oil Content ◽  
Morphological Changes ◽  
Dry Weight ◽  
Dry Matter Accumulation

Self-pollinated seed from normal and erucic acid free plants of summer rapeseed (Brassica napus L.) was harvested at weekly intervals from pollination to maturity. Oven-dried whole seeds and their component parts were weighed and analyzed for oil content and fatty acid composition. Oil and dry matter accumulation followed sigmoidal patterns, most of the deposition occurring between 14 and 35 days after pollination (DAP). The relative contribution of the testa, endosperm and embryo to dry weight and oil content of whole seeds changed significantly during seed development. Oil content of the developing embryo varied from 22 to 44%, and the testa from 1.6 to 13%, although at maturity only 6 to 8% oil was found in the testa and adhering aleurone. The nucleate endosperm oil content was estimated to be low and in the order of 2 to 2.5%. In 7- to 14-day-old seeds the dry weight, oil content and fatty acid composition were largely determined by the testa and endosperm. From 14 to 21 DAP the testa and embryo were dominant and after 21 DAP the embryo was the controlling influence on the seed characteristics studied.Oils of the testa, nucleate endosperm and embryo differed in fatty acid composition. In seeds free of erucic acid, the ratios of the 18 carbon fatty acids of the embryo and testa remained nearly constant from 21 DAP to maturity. This suggested that the variation in fatty acid composition as well as oil content during seed development in this material was due to disproportionate changes in the contribution of the testa, nucleate endosperm and embryo. However, in developing seeds capable of producing erucic acid a change in the ratio of fatty acid synthesis occurred in both the testa and embryo.

scholarly journals A taxonomic review of the family Trachipteridae (Acanthomorpha: Lampridiformes), with an emphasis on taxa distributed in the western Pacific Ocean

Zootaxa ◽  
2021 ◽  
Vol 5039 (3) ◽  
pp. 301-351
Author(s):  
JENNIFER M. MARTIN ◽  
ERIC J. HILTON
Keyword(s):  
Pacific Ocean ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Early Life History ◽  
The Body ◽  
Western Pacific ◽  
Western Pacific Ocean ◽  
Taxonomic Review ◽  
The Family ◽  
The Western Pacific

The family Trachipteridae—the Ribbonfishes, Dealfishes, and their relatives—has a circumglobal distribution, with at least 10 species in three genera (Zu Walters & Fitch 1960, Desmodema Walters & Fitch 1960, and Trachipterus Goüan 1770) that are characterized by elongate, extremely laterally compressed bodies, large eyes, absence of ribs, spines on lateral-line scales, greatly protrusible mouths, and a lack of pelvic fins in adults. They are also known for the drastic morphological changes that occur during ontogeny. Trachipterids are poorly represented in collections due to the fragile nature of their bodies. Most studies of the Trachipteridae have been limited by the numbers, developmental stages, and the completeness of the specimens that were examined. Along with the lack of available material, incomplete and conflicting character information compounds the taxonomic confusion of Trachipteridae. Despite the body of regional revisions that have examined trachipterid taxonomy, none have synthesized a suite of morphological characters across ontogeny. The goals of this paper are to (1) revise the family Trachipteridae, (2) revise the genera Trachipterus, Zu, and Desmodema, including information regarding ontogeny and biogeography, and 3) address the alpha taxonomy of Zu, Desmodema, and Trachipterus from the western Pacific Ocean. We recognize possibly five species of Trachipterus as being present in the western Pacific, as well as two species of both Zu and Desmodema. Despite additions to the specimen base that allows refinement of taxonomy and diagnoses, there are still large knowledge gaps associated with the taxonomic review of Trachipteridae. These reflect incomplete understanding of geographic distribution of taxa which may mask unrecognized taxonomic variability. The genus Trachipterus specifically remains problematic and will require greater detailed global study. Early life history stages remain unknown for several taxa which hinders full interpretation of ontogenetic transitions. Protracted transitions, some of which are clarified here, further confuse stage-based diagnoses and must be considered in future analyses of this family.  

scholarly journals Identification and evaluation of the novel genes for transcript normalization during female gametophyte development in sugarcane

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12298
Author(s):  
Maokai Yan ◽  
Xingyue Jin ◽  
Yanhui Liu ◽  
Huihuang Chen ◽  
Tao Ye ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sexual Reproduction ◽  
Reference Genes ◽  
Female Gametophyte ◽  
Developmental Stages ◽  
Reproductive Organs ◽  
The Novel ◽  
Biofuel Feedstock ◽  
Gametophyte Development ◽  
Female Gametophyte Development

Background Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). Method In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). Results Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.

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