Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Seed development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,477 records · Page 82Linked to original sources
PubMed1978

Amino Acid composition of germinating cotton seeds.

Total and free amino acid composition of germinating cotton seeds (Gossypium hirsutum L.) was determined. The germinating seeds were separated into cotyledon and developing axis fractions daily and the composition of each tissue was summed to get the whole seed composition. By separating the developing seeds into these two tissue fractions, and determining total and free amino acids, a balance sheet was developed for each amino acid. This technique allowed changes in distribution with time of each amino acid to be followed in each tissue. Data for total content and amount in protein of each amino acid are presented. Asparagine increased in the whole seed, and most of this increase was found in the free pool of the developing axis. Other amino acids (e.g. arginine, glutamic acid) increased in the free pool but showed an over-all decrease, indicating that they were being metabolized. Amino acid contents of storage and nonstorage protein isolates were determined.

Journal Article↗
PubMed1998

Expression patterns of GASA genes in Arabidopsis thaliana: the GASA4 gene is up-regulated by gibberellins in meristematic regions.

The GASA gene family previously identified in Arabidopsis belongs to a wide-spread class of genes found in mono- and dicotyledonous plants, all structurally related to the original GA-regulated GAST1 gene from tomato. They encode small peptides (97 to 112 residues) of unknown function sharing a 60 amino acid conserved C-terminal domain comprising twelve conserved cysteine residues which define a pattern not related to other known cysteine-rich motifs. Northern blot hybridization analysis revealed sequential expression of three genes during flowering, silique development and seed germination. GASA4 transcripts were detected in flower buds. GASA1 transcripts markedly accumulated in siliques, about five days after pollination, and correlated with the peak of GA biosynthesis at this stage of silique development. GASA3 transcripts accumulated at the end of the maturation stage of the silique, and transcripts were still present in dry seeds but degraded rapidly during imbibition. In addition, the GASA4 gene was again actively transcribed after germination and this expression was shown to be dependent on the presence of GAs in GA-deficient mutants. Immunoblot analysis confirmed the presence of the GASA4 gene product in flower buds, seedlings and roots. We focused on the GASA4 gene and characterized its expression. The upstream region (-890 to +128) was fused to the GUS reporter gene. GASA4/GUS expression was detected in transgenic Arabidopsis primarily in all meristematic regions, including vegetative, inflorescence and floral meristems, as well as primary and lateral root tips. In a GA-deficient background (ga1-3), GUS activity in the vegetative meristem was detected only in the presence of supplied GA. In root and flower meristems, basal GUS activity was slightly enhanced by exogenous GA. Interestingly, GA strongly inhibit GUS activity in expanding cotyledons and leaves in ga1-3 mutants supplied with exogenous GAs, as well as in the wild type. The GA-dependent meristem-specific expression pattern suggests that the GASA4 protein plays a role in dividing cells rather than in elongating cells.

Amino Acid Sequence↗
PubMed1991

Biochemical effects of heat shock and caffeine on post-irradiation oxic and anoxic damage in barley seeds of low and high water content.

Wet heat shock (60 degrees C, 90 s) and caffeine (3.8 X 10(-4) M) afford significant radioprotection against post-irradiation O2-dependent damage which develops in seeds of approximately 3.5% moisture content. The damage was assessed in terms of seedling injury on the eighth day of growth. An increase in seedling injury is clearly seen, associated with a parallel increase in the peroxidase activity. There is a concomitant decrease in the content of total peroxides. Both these post-irradiation treatments potentiate the O2-independent component of seedling injury, irrespective of the seed moisture content. Analysis of the peroxidase activity in the seedlings using non-denaturing polyacrylamide gel electrophoresis reveals that two additional bands appear with the post-irradiation oxic damage. Radioprotection against this damage by caffeine, heat shock and O2-free post-irradiation hydration is accompanied by the disappearance of these two additional bands. However there is no appearance of the two additional bands in the peroxidase family even though the enzyme activity is substantially increased due to the action of caffeine and/or heat shock on the post-irradiation O2-independent pathway of damage. The probable mechanisms of radioprotection are discussed in this paper.

Caffeine↗
PubMed1999

Seed-specific overexpression of phytoene synthase: increase in carotenoids and other metabolic effects

A bacterial phytoene synthase (crtB) gene was overexpressed in a seed-specific manner and the protein product targeted to the plastid in Brassica napus (canola). The resultant embryos from these transgenic plants were visibly orange and the mature seed contained up to a 50-fold increase in carotenoids. The predominant carotenoids accumulating in the seeds of the transgenic plants were alpha and beta-carotene. Other precursors such as phytoene were also detected. Lutein, the predominant carotenoid in control seeds, was not substantially increased in the transgenics. The total amount of carotenoids in these seeds is now equivalent to or greater than those seen in the mesocarp of oil palm. Other metabolites in the isoprenoid pathway were examined in these seeds. Sterol levels remained essentially the same, while tocopherol levels decreased significantly as compared to non-transgenic controls. Chlorophyll levels were also reduced in developing transgenic seed. Additionally, the fatty acyl composition was altered with the transgenic seeds having a relatively higher percentage of the 18 : 1 (oleic acid) component and a decreased percentage of the 18 : 2 (linoleic acid) and 18 : 3 (linolenic acid) components. This dramatic increase in flux through the carotenoid pathway and the other metabolic effects are discussed.

Journal Article↗
PubMed2001

Isolation and expression analysis of gibberellin 20-oxidase homologous gene in apple.

To characterize the gibberellin (GA) 20-oxidase gene in apple, the genomic and cDNA clone from "Fuji" apple (accession no. AB037114) was isolated. The deduced amino acid sequence of this cDNA showed 71% and 66% identity to those of GA 20-oxidase cloned from French bean and Arabidopsis, respectively. The transcript of this gene was detected mainly in immature seeds between 1-3 months after full bloom. These results suggested that this apple GA 20-oxidase gene might be involved in GA biosynthesis in developing apple seed.

Amino Acid Sequence↗
PubMed2003

[The influence of seed maturity and seed coat on the germination of Bupleurum chinense and B. falcatum].

OBJECTIVE: To investigate the factors influencing the seed germination of Bupleurum chinense and B. falcatum. METHOD: The seeds of different maturity, and the seeds whose coat were removed or nicked before dipping in water, were germinated in a light growth chamber. RESULT: The different inflorescence level represents different development period. Seeds harvested from cultivation have different maturity. The germination rate of the seeds in period I to III was nearly zero, and it was significant different from period IV to VII. The seed coat is not an obstacle for water absorption or gas exchange, but its removal led to significant increase of seed germination rate. However, to dip the seeds without coat into water for 48 h had no more effect on germination. CONCLUSION: The seed maturity and germination inhibitors in seed coat are two important factor influencing seed germination in B. chinense and B. falcatum.

Bupleurum↗
PubMed2006

The homeobox gene GLABRA2 affects seed oil content in Arabidopsis.

Despite a good understanding of genes involved in oil biosynthesis in seed, the mechanism(s) that controls oil accumulation is still not known. To identify genes that control oil accumulation in seed, we have developed a simple screening method to isolate Arabidopsis seed oil mutants. The method includes an initial screen for seed density followed by a seed oil screen using an automated Nuclear Magnetic Resonance (NMR). Using this method, we isolated ten low oil mutants and one high oil mutant. The high oil mutant, p777, accumulated 8% more oil in seed than did wild type, but it showed no differences in seed size, plant growth or development. The high-oil phenotype is caused by the disruption of the GLABRA2 gene, a previously identified gene that encodes a homeobox protein required for normal trichome and root hair development. Knockout of GLABRA2 did not affect LEAFY COTYLEDON 1 and PICKLE expression in developing embryo. The result indicates that in addition to its known function in trichome and root hair development, GLABRA2 is involved in the control of seed oil accumulation.

Adhesives↗
PubMed1995

Systematic changes in gaping during the ontogeny of pecking in ring doves (Streptopelia risoria).

Food pecking in the ring dove is a skilled prehensile response that is similar to, but simpler than, many other prehensile responses. Previous work has shown that this response is initially poorly executed and requires experience for its accurate direction and coordination. The response involves two components: the thrusting of the bird's head toward food, and the opening and closure of the beak around food. Here, this second component, called gape, is followed through development with a precise measurement system. Four squabs moved through a similar sequence of three gape topographies, each of which is more efficient in picking up seed, during development. The present outcome, together with other work, argues for a substantial contribution of experience with pecking to the development of food pecking. We discuss the implications of these findings for understanding the ontogeny of motor control and for understanding how experience affects behavioral development.

Aging↗
PubMed2001

Isolation and characterization of coagulant extracted from Moringa oleifera seed by salt solution.

It is known that M. oleifera contains a natural coagulant in the seeds. In our previous research, the method using salt water to extract the active coagulation component from M. oleifera seeds was developed and compared with the conventional method using water. In this research, the active coagulation component was purified from a NaCl solution crude extract of Moringa oleifera seeds. The active component was isolated and purified from the crude extract through a sequence of steps that included salting-out by dialysis, removal of lipids and carbohydrates by homogenization with acetone, and anion exchange. Specific coagulation activity of the active material increased up to 34 times more than the crude extract after the ion exchange. The active component was not the same as that of water extract. The molecular weight was about 3000 Da. The Lowry method and the phenol-sulfuric acid method indicated that the active component was neither protein nor polysaccharide. The optimum pH of the purified active component for coagulation of turbidity was pH 8 and above. Different from the conventional water extracts, the active component can be used for waters with low turbidity without increase in the dissolved organic carbon concentration.

Chromatography, Ion Exchange↗
PubMed2004

Sulphur and nitrogen nutrition influence the response of chickpea seeds to an added, transgenic sink for organic sulphur.

In order to increase the concentration of the nutritionally essential sulphur amino acids in seed protein, a transgene encoding a methionine- and cysteine-rich protein, sunflower seed albumin (SSA), was transferred to chickpeas (Cicer arietinum L). Transgenic seeds that accumulated SSA contained more methionine and less oxidized sulphur than the controls, suggesting that additional demand for sulphur amino acids from the expression of the transgene stimulated sulphur assimilation. In addition, the activity of trypsin inhibitors, a known family of endogenous, sulphur-rich chickpea seed proteins, was diminished in transgenic, SSA-containing seeds compared with the non-transgenic controls. Together, these results indicate that the reduced sulphur sequestered into SSA was supplied partly by additional sulphur assimilation in the developing transgenic seeds, and partly by some diversion of sulphur amino acids from endogenous seed proteins. Growth of chickpeas on nutrient with a high sulphur-to-nitrogen ratio increased the total seed sulphur content and the accumulation of sulphur amino acids in the seeds, and partly mitigated the effect of SSA accumulation on the trypsin inhibitor amount. The results suggest that free methionine and O-acetylserine (OAS) acted as signals that modulated chickpea seed protein composition in response to the variation in sulphur demand, as well as in response to variation in the nitrogen and sulphur status of the plant.

Cicer↗
PubMed2004

Comparative studies on the Arabidopsis aldehyde oxidase (AAO) gene family revealed a major role of AAO3 in ABA biosynthesis in seeds.

The Arabidopsis aldehyde oxidase 3 (AAO3) gene encodes an enzyme that catalyzes the final step of ABA biosynthesis. AAO3 has been shown to be the major AAO involved in ABA biosynthesis in leaves under stress conditions. On the other hand, less severe phenotypes of the aao3 seeds suggested that other AAO(s) might also be involved in ABA biosynthesis in seeds. Among four AAOs (AAO1-AAO4), AAO1 and AAO4 were the AAO expressed most abundantly in dry seeds and developing siliques, respectively. Unlike aao3, single loss-of-function mutants for AAO1 and AAO4 (aao1 and aao4), failed to show significant changes in endogenous ABA levels in seeds when compared with wild type. While aao3 seed germination was resistant to the gibberellin biosynthesis inhibitor, uniconazole, aao1 and aao4 showed no resistance and were similar to wild type. These results indicate that AAO3, but not AAO1 or AAO4, plays an important role in ABA biosynthesis in seeds. Mutations of AAO1 or AAO4 in the aao3 mutant background enhanced ABA deficiency in seeds, demonstrating that both gene products contribute partially to ABA biosynthesis in the aao3 mutant background. However, considering the enzymatic characters of AAO1 and AAO4, their involvement in ABA biosynthesis in wild-type seeds may be negligible. We have concluded that AAO3 is the AAO that plays a major role in ABA biosynthesis in Arabidopsis seeds as well as in leaves.

Abscisic Acid↗
PubMed1989

Gibberellins in Embryo-Suspensor of Phaseolus coccineus Seeds at the Heart Stage of Embryo Development.

Gibberellins (GAs) in suspensors and embryos of Phaseolus coccineus seeds at the heart stage of embryo development were analyzed by combined gas chromatography-mass spectrometry (GC-MS). From the suspensor four C(19)-GAs, GA(1), GA(4), GA(5), GA(6), and one C(20) GA, GA(44), were identified. From the embryo, five C(19)-GAs GA(1), GA(4), GA(5), GA(6), GA(60) and two C(20) GAs, GA(19) and GA(44) were identified. The data, in relation to previous results, suggest a dependence of the embryo on the suspensor during early stages of development.

Journal Article↗
PubMed1978

Growth of "seeded" cellulolytic enrichment cultures on mesquite wood.

Eleven enrichment cultures were developed by a "seeded" enrichment culture technique, and one was developed by a simple enrichment technique. The seeded enrichment, the pure "seed," and the simple enrichment cultures were compared during growth on mesquite wood, cotton, carboxymethylcellulose, and cellobiose. All of the enrichment cultures were cellulolytic and exceeded the pure seed cultures in mesquite wood hydrolysis and/or viable cell count. Yeast extract improved, but was not essential for, growth of the seeded enrichment cultures on carboxymethylcellulose. Two of the seeded enrichment cultures, CAD5 and CAD11, grew best at 37 degrees C and pH 7.0 on mesquite wood. A 1.0% (wt/vol) wood concentration was optimum for their growth.

Journal Article↗
PubMed1990

The maize zein gene zE19 contains two distinct promoters which are independently activated in endosperm and anthers of transgenic Petunia plants.

The activity, tissue specificity and temporal expression of the tandem promoter region preceding a maize zein gene (zE19, encoding a 19 kDa zein protein) were tested in transgenic Petunia plants. To simplify the analysis, the tandem promoter as well as each of the two separate promoter regions were fused to the beta-glucuronidase (GUS) reporter gene. All of the three constructs directed the synthesis of GUS in the endosperm of transformed seeds indicating that both separate promoters are independently activated and show the same tissue and cell type specificity observed for zein genes in maize. The kinetics of accumulation and the localization of GUS activity are not coordinated with those of Petunia endogenous seed storage proteins during the development of transformed seeds. Unexpectedly, we detected high levels of GUS activity in anthers of transformed Petunia plants for all three constructs. This appears to reflect the expression pattern of zein genes in maize, since we detect zein transcripts in anthers. Finally, we discuss the possible origin and function of the tandem promoter arrangement on the basis of these data.

Base Sequence↗