Giant Embryo Research Articles

Quenching of Cytotoxic Reactive Carbonyl Species by Black Rice with Giant Embryo

Reactive carbonyl species (RCS) are cytotoxic molecules originating from lipid peroxidation and sugar oxidation. A robust and efficient method based on high resolution mass spectrometry was used to test the ability of water‐soluble rice extracts to inhibit protein carbonylation induced by RCS. The model protein ubiquitin was incubated in vitro with different RCS such as 4‐hydroxy‐trans‐2‐nonenal (HNE) in presence of increasing concentration of various rice extracts. After 24 hours of incubation, the reaction was stopped and ubiquitin was analyzed by HRMS to determine the extent of protein modification due to the RCS, and to observe its modulation in presence of the extracts. The different rice extracts inhibited the formation of RCS‐induced protein modificationsto different extents. A black sticky rice with giant embryo (IC50=~29.1) strongly inhibited protein modification by the HNE than white rice (IC50=~151.0). These findings suggest that certain bioactive components in water‐soluble fractions of specific rice varieties effectivelysequester RCS, and that such rice variety can be valuable for dietary strategy for optimal health.This work was supported by Rural Development Administration (PJ010059), Republic of Korea.

Using giant scarlet runner bean embryos to uncover regulatory networks controlling suspensor gene activity.

One of the major unsolved issues in plant development is understanding the regulatory networks that control the differential gene activity that is required for the specification and development of the two major embryonic regions, the embryo proper and suspensor. Historically, the giant embryo of scarlet runner bean (SRB), Phaseolus coccineus, has been used as a model system to investigate the physiological events that occur early in embryogenesis—focusing on the question of what role the suspensor region plays. A major feature distinguishing SRB embryos from those of other plants is a highly enlarged suspensor containing at least 200 cells that synthesize growth regulators required for subsequent embryonic development. Recent studies have exploited the giant size of the SRB embryo to micro-dissect the embryo proper and suspensor regions in order to use genomics-based approaches to identify regulatory genes that may be involved in controlling suspensor and embryo proper differentiation, as well as the cellular processes that may be unique to each embryonic region. Here we review the current genomics resources that make SRB embryos a compelling model system for studying the early events required to program embryo development.

흑찰거대배아미를 이용한 팝라이스와 흑미차의 품질 특성

Research and Development Bureau, RDA, Jeonju 560-500, KoreaReceived October 17, 2014/Revised November 23, 2014/Accepted November 26, 2014Recently developed black waxy rice with a giant embryo (‘Nunkeunheukchal’, BGE) was selected and processed to produce high quality nutritional food. BGE contains high levels of several phytochem-icals with antioxidant activities, as well as other reported health beneficial properties. In addition, the giant embryo has high protein, lipid, and amino acids contents. Within the free amino acids, γ-aminobutyric acid (GABA), a major inhibitory neurotransmitter, has long been used for treating the aftereffects of brain injuries and stroke. A method for manufacturing pop-rice and black rice tea by popping process in BGE is provided to increase a taste, nutrition and functionality. The produced ‘pop-rice’ showed increased protein (11.3%) and lipid (3.7%) contents compared with control variety, IB (‘Ilmibyeo’). In addition, melanoidin related products, polyphenol and functional amino acid con-tents were increased by the popping process. Pop-rice tea made of BGE showed the highest extraction of total sugar, glucose, raffinose and sucrose (4 times higher than brown rice) by hot water. Scavenging activity (SC

P.6.b.005 Effect of GABA extract of giant embryo black sticky rice on alcohol-related indices after alcohol drinking in social drinkers

P.6.b.005 Effect of GABA extract of giant embryo black sticky rice on alcohol-related indices after alcohol drinking in social drinkers

Functional rice giant embryo and Aranghyangchal reduce blood glucose level and enhance antioxidative defense status in high fat-fed mice

The effect of functional rice giant embryo and Aranghyangchal on the glucose metabolism and antioxidative defense status in high fat-fed C57BL/6N mice were investigated. The animals were randomly divided into four dietary groups: normal control (NC), high fat (HF), and high fat supplemented with giant embryo rice (HF-GE) or Aranghyangchal rice (HF-AR). After 8 weeks of feeding them with experimental diets, the HF mice exhibited a marked increase in the blood glucose concentration, plasma insulin level, and lipid peroxidation and a significant decrease in the hepatic glycogen level relative to the NC group. On the other hand, diet supplementation of the rice samples suppressed this high fat diet-induced hyperglycemia and oxidative stress through inhibition of the glucose-regulating enzymes and activation of the antioxidant enzymes. These findings demonstrate that the giant embryo and Aranghyangchal rice may be beneficial as biomaterials in the development of functional food with hypoglycemic and antioxidative properties.

OR12-1 * EFFECT OF GABA EXTRACT OF BLACK STICKY RICE WITH GIANT EMBRYO ON ALCOHOL-RELATED INDICES AFTER ACUTE ALCOHOL INTAKE IN SOCIAL DRINKERS

Introduction. This study was performed to evaluate the effect and safety of a high GABA containing extract (GABA extract) of Black Sticky Rice with giant embryo (BSRGE) on alcohol-related indices after acute alcohol intake in healthy social drinkers. Methods. Fifty subjects were randomized to GABA extract group, GABA extract and alcohol drinking group (GA) or placebo intake and alcohol drinking group (PA) in a double-blind design. BAC and the Biphasic Alcohol Effects Scale were measured. Results. The peak and AUC of total stimulation scale score after alcohol intake in women was significantly higher in GA than PA group (p = 0.002; p = 0.001). The peak and AUC of total score on the sedation scale after alcohol intake in men was significantly lower in GA than PA group (p = 0.001; p = 0.002), whereas it was significantly higher in GA than PA group of women (p = 0.014; p = 0.018). The AUC for BAC in men was significantly lower in GA than PA group (p < 0.0001). Conclusion. Co-administration of a GABA extract to social drinkers while drinking alcohol is supposed to affect alcohol-related indices in terms of pharmacodynamics and pharmacokinetics. Further studies are needed to find the extract mechanism and to investigate the benefit GABA extract from BSRGE in alcohol-drinking subjects.

Effect of instant cooked giant embryonic rice on body fat weight and plasma lipid profile in high fat-fed mice.

The comparative effects of instant cooked rice made from giant embryo mutant or ordinary normal rice on body weight and lipid profile in high fat-fed mice were investigated. The animals were given experimental diets for seven weeks: normal control (NC), high fat (HF), and HF supplemented with instant normal white (HF-NW), normal brown (HF-NB), giant embryonic white (HF-GW), or giant embryonic brown (HF-GB) rice. The HF group showed markedly higher body weight, body fat, plasma and hepatic triglyceride and cholesterol concentrations, and atherogenic index relative to NC group. However, instant rice supplementation counteracted this high fat-induced hyperlipidemia through regulation of lipogenesis and adipokine production. The GB rice exhibited greater hypolipidemic and body fat-lowering effects than the GW or NB rice. These findings illustrate that the giant embryo mutant may be useful as functional biomaterial for the development of instant rice with strong preventive action against high fat diet-induced hyperlipidemia and obesity.

Loss of Function of the Cytochrome P450 Gene CYP78B5 Causes Giant Embryos in Rice

Rice (Oryza sativa L.) is one of the most important food crops in the world. Most kernel oil and micro-nutrients are located in the embryo whereas starch is mainly in the endosperm. Although embryo size is important for rice grain yield and food processing, little is known about the genetic mechanisms controlling embryo size. We characterized a rice giant embryo mutant, giant embryo (ge), which was derived from wild-type Kinmaze by chemical mutagenesis. The large embryo size resulted from larger cell size. The gene controlling the giant embryo trait was cloned by a map-based approach, and shown to encode cytochrome P450 protein CYP78B5, which was previously designated as CYP78A13. Gain-of-function transgenic experiments on OsGE/CYP78B5 in the ge mutant restored the normal seed phenotype. Expression analysis showed that the OsGE/CYP78B5 gene product accumulated mainly in young developing seeds. Subcellular localization indicated that OsGE/CYP78B5 resides in the peroxisomes, and the N-terminal 51 amino acid residues function as a targeting signal. The IAA levels were one-third those of wild type in GE mutants at 6 days after fertilization, yet the embryonic cells were much larger. OsGE/CYP78B5 also regulates expression levels of auxin-responsive and cyclin-related genes. Isolation of GE provides an opportunity to manipulate the nutritive composition and distribution of the grain by marker-assisted selection and transgenic approaches.

Hypolipidemic and Body Fat–Lowering Effects of Giant Embryo Brown Rice (Seonong 17 and Keunnunjami) in High‐Fat‐Fed Mice

ABSTRACTThe effects of giant embryo brown rice Seonong 17 and Keunnunjami, in comparison with that of ordinary normal brown rice, on the body weight and lipid profile in mice under a high‐fat diet condition were investigated. The animals were fed with experimental diets for eight weeks: normal control, high fat (HF), and high fat supplemented with normal brown rice, Seonong 17 rice, or Keunnunjami rice powder. Their body and fat weights, lipid profiles, lipogenic enzyme activities, and adipokine concentrations were determined. Significant differences between the animal groups were analyzed with Tukey's test (P &lt; 0.05). A marked increase in the body weight and fat, plasma triglyceride and total cholesterol concentrations, and free fatty acid level were found in HF mice relative to the control group. On the other hand, diet supplementation with rice, particularly the giant embryo rice samples, significantly suppressed this high‐fat‐induced body weight gain and hyperlipidemia via regulation of lipogenesis and adipokine production. Both the Seonong 17 and Keunnunjami exhibited greater hypolipidemic and body fat–lowering effects than the normal brown rice. The results demonstrate that these giant embryo mutants may be beneficial as biomaterials for functional foods with antiobesity and hypolipidemic effects.

Hypoglycemic and Antioxidative Effects of Instant Cooked Giant Embryonic Rice in High‐Fat‐Fed Mice

ABSTRACTThe effect of instant cooked rice made from giant embryo mutant or ordinary normal rice on the glucose metabolism and antioxidative defense system in mice under a high‐fat (HF) diet condition was investigated. The animals were randomly divided and given experimental diets for seven weeks: normal control diet, HF diet, and HF diet supplemented with instant normal white, normal brown, giant embryonic white, or giant embryonic brown rice. At the end of the experimental period, the HF mice showed a marked increase in the blood glucose level, insulin concentration, and plasma and erythrocyte lipid peroxidation and a significant decrease in the glycogen level relative to the control group. However, diet supplementation with instant cooked giant embryonic and normal brown rice counteracted this high‐fat‐induced hyperglycemia and oxidative stress through regulation of the glucose‐regulating and antioxidant enzyme activities. The giant embryonic brown rice was the most effective in improving the glucose metabolism and antioxidant defense status in mice under the HF diet condition. The results demonstrate that the giant embryo rice mutant may be useful in the development of instant cooked rice with strong hypoglycemic and antioxidative properties.

Control of Rice Embryo Development, Shoot Apical Meristem Maintenance, and Grain Yield by a Novel Cytochrome P450

Angiosperm seeds usually consist of two major parts: the embryo and the endosperm. However, the molecular mechanism(s) underlying embryo and endosperm development remains largely unknown, particularly in rice, the model cereal. Here, we report the identification and functional characterization of the rice GIANT EMBRYO (GE) gene. Mutation of GE resulted in a large embryo in the seed, which was caused by excessive expansion of scutellum cells. Post-embryonic growth of ge seedling was severely inhibited due to defective shoot apical meristem (SAM) maintenance. Map-based cloning revealed that GE encodes a CYP78A subfamily P450 monooxygenase that is localized to the endoplasmic reticulum. GE is expressed predominantly in the scutellar epithelium, the interface region between embryo and endosperm. Overexpression of GE promoted cell proliferation and enhanced rice plant growth and grain yield, but reduced embryo size, suggesting that GE is critical for coordinating rice embryo and endosperm development. Moreover, transgenic Arabidopsis plants overexpressing AtCYP78A10, a GE homolog, also produced bigger seeds, implying a conserved role for the CYP78A subfamily of P450s in regulating seed development. Taken together, our results indicate that GE plays critical roles in regulating embryo development and SAM maintenance.

High Expression of Tocochromanol Biosynthesis Genes Increases the Vitamin E Level in a New Line of Giant Embryo Rice

'Shangshida No. 5' is a new variety of giant embryo rice derived from a single-point mutation of the giant embryo gene (ge) in 'Chao2-10' rice. This study quantified the levels of eight vitamin E homologues (α-, β-, γ-, and δ-tocopherol and α-, β-, γ-, and δ-tocotrienol) in brown rice, embryos, endosperm, and developing seeds of giant embryo and normal embryo rice using a normal phase high-performance liquid chromatographic method. Quantitative RT-PCR analysis was conducted to reveal the different expression patterns of the ge gene and tocochromanol biosynthesis genes in developing giant and normal embryo seeds. The total vitamin E content in 'Shangshida No. 5' brown rice was 52.54 mg α-tocopherol equivalent (α-TE)/kg, of which α-tocopherol constituted 49.14 mg/kg, which was approximately 2.2-fold greater than that in 'Chao2-10' brown rice. In giant embryo seeds, the expression level of the ge gene was higher than that in normal embryo seeds during early developmental stages. These results are the first to indicate that coup-regulated expression of the OsHPPD, OsHPT, and OsMPBQ MT2 genes might be the primary reason for the large accumulation of α-tocopherol in giant embryo rice seeds. The different transcription pattern of the tocochromanol biosynthesis genes in 'Shangshida No. 5' rice seeds compared with 'Chao2-10' rice seeds is attributable to the ge mutation and the different expression level of the ge gene in giant embryo seeds.

Modulatory effects of functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in mice fed with a high fat diet

The effects of the functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in male C57BL/6N mice under high fat diet conditions were investigated. The animals were randomly placed into four dietary groups: normal control (NC group), high fat (HF group), and high fat supplemented with giant embryo (HF-GE group) or Aranghyangchal (HF-AR group). After 8weeks, a marked increase in the body weight and plasma triglyceride and total cholesterol concentrations were found in the HF mice relative to the control group. However, the addition of the functional rice samples in the high fat diet reduced the body weight gain and significantly decreased the lipid levels through inhibition of lipogenesis and regulation of adipokine production. The results demonstrate that the functional rice grains giant embryo and Aranghyangchal may both be useful as biomaterials in the development of functional food with therapeutic potential against high fat diet-induced hyperlipidemia.

GIANT EMBRYO encodes CYP78A13, required for proper size balance between embryo and endosperm in rice

Among angiosperms there is a high degree of variation in embryo/endosperm size in mature seeds. However, little is known about the molecular mechanism underlying size control between these neighboring tissues. Here we report the rice GIANT EMBRYO (GE) gene that is essential for controlling the size balance. The function of GE in each tissue is distinct, controlling cell size in the embryo and cell death in the endosperm. GE, which encodes CYP78A13, is predominantly expressed in the interfacing tissues of the both embryo and endosperm. GE expression is under negative feedback regulation; endogenous GE expression is upregulated in ge mutants. In contrast to the loss-of-function mutant with large embryo and small endosperm, GE overexpression causes a small embryo and enlarged endosperm. A complementation analysis coupled with heterofertilization showed that complementation of ge mutation in either embryo or endosperm failed to restore the wild-type embryo/endosperm ratio. Thus, embryo and endosperm interact in determining embryo/endosperm size balance. Among genes associated with embryo/endosperm size, REDUCED EMBRYO genes, whose loss-of-function causes a phenotype opposite to ge, are revealed to regulate endosperm size upstream of GE. To fully understand the embryo-endosperm size control, the genetic network of the related genes should be elucidated.

GABA 고함유 흑찰거대배아미의 투여가 C57BL/6형 생쥐의 알코올 섭취량에 미치는 영향

It is known that black sticky rice with giant embryo (BSRGB, Milyang 263) and giant embryo rice (GER) contains higher levels of GABA than rice. Therefore, feeding BSRGB, GER, or rice freely to C57BL/6 mice with two-hour alcohol intake for 16 days was investigated. For two-hour alcohol intake, a repeated measure ANOVA (three treatment groups repeated across 16 days; 8 two-day blocks) yielded a significant group by block interaction (df=16, F=3.109, p=0.004). The independent t-test showed that significant suppression of two-hour alcohol intake was observed when subjects were administered with BSRGB, compared with the rice alone across all the two-day blocks (p<0.05). The paired t-test revealed that a significant suppression of two-hour alcohol intake was observed starting 4 to 16 days after freely feeding with BSRGB compared to before feeding. However, there is no significant difference in the two-hour alcohol intake observed between the before and after administration of rice. A repeated measure ANOVA revealed no significant group by block interaction for 22-hour water intake and body weight. However, a repeated measure ANOVA revealed a significant grouping by block interaction for food intake. These results indicate a change of two-hour alcohol intake is presumably caused by GABA, which is found in higher levels in BSRGB than in rice.

Comparative studies on major nutritional components of black waxy rice with giant embryos and its rice bran

The concentration of nutrients in brown rice is mainly associated with embryo size. Various beneficial components have been purified from rice bran. Recently developed black waxy rice with a giant embryo (‘Milyang 263’, BGE), which is the ge t mutant of the GE gene, was selected and analyzed to produce high quality nutritional components. γ-Aminobutyric acid (GABA) content in BGE rice bran, one of the most important nutritional compounds in rice, showed a 10.6-fold increase (2.66±0.48 mg/g) compared to that of BGE brown rice (0.25±0.01 mg/g). In addition, brown rice and BGE rice bran showed enriched amylopectin (94.5±0.5 and 97.0±0.0%) and bioactive anthocyanin [Cy-3-G: 75.15±4.18 (brown rice), 82.97±0.81 (rice bran) and Pn-3-G: 1.52±0.50 (brown rice), 4.33±0.20 (rice bran); mg/100 g] contents. These results suggest that BGE rice bran can be used as an excellent raw material to efficiently produce high quality essential amino acids, cyanidin-3 glycoside-enriched anthocyanins, and GABA.

Study on Sowing Conditions of a Rice Cultivar &quot;Tohokuhai 202&quot; with Giant Embryo and Low Amylose Content

Study on Sowing Conditions of a Rice Cultivar &quot;Tohokuhai 202&quot; with Giant Embryo and Low Amylose Content

Comparative studies on major nutritional components of black waxy rice with giant embryo and its rice bran

Comparative studies on major nutritional components of black waxy rice with giant embryo and its rice bran

A transposable element insertion within ZmGE2 gene is associated with increase in embryo to endosperm ratio in maize

Most of the maize kernel oil is located in the embryo while the majority of starch is located in the endosperm. Maize kernel composition and value are affected significantly by the ratio of the embryo size to the endosperm size; however, the genetic regulation of embryo to endosperm ratio (EER) in maize is unknown. Here we identified ZmGE2 gene, which encodes a cytochrome p450 protein, as a gene associated with EER variation in maize. We first expressed rice Giant Embryo (GE) gene driven by oleosin promoter in maize and detected a 23.2 % reduction in EER in transgenic seeds, demonstrating the existence of evolutionarily conserved mechanisms for EER determination in rice and maize. We next identified maize GE2, a homolog of rice GE sharing 70 % identity in amino sequence, as a candidate based on the similar expression pattern and co-localization with a previously detected QTL for EER. Followed by linkage and association mapping, a 247-bp transposable element (TE) insertion in 3'-untranslated region of ZmGE2 gene was identified to be associated with increase in EER and kernel oil content. Expression level of the favorable ZmGE2 allele containing the 247-bp TE insertion was strongly reduced. In addition, the 247-bp TE insertion site was a selection target during the artificial long-term selection for the high EER trait in a high oil population. This is the first report that demonstrates an association of ZmGE2 with EER variation in maize and identifies ZmGE2 gene as a promising target for manipulation of EER and grain composition by either transgenic approach or molecular breeding in maize.

Physicochemical Properties of a Giant Embryo Mutant Induced by T-DNA Insertion in Rice

This study was conducted to determine the physicochemical properties of a giant embryo rice ‘47JB-4-B-5-B’derived from the cross between ‘47’ a mutant of ‘wayoung’induced by T-DNA insertion, and ‘unam’ The grain appearance and chemical components of the embryo were analyzed and compared with a donor cultivar, ‘wayoung’ The proportion of embryo weight to grain weight of ‘47 JB-4-B-5-B’was 2.2 times heavier (6.7%) than that (3.1%) of ‘wayoung’ Total free amino acid content (75.81 mg/100 g) of ‘47JB-4-B-5-B’was 2.1 times higher than that of ‘wayoung’ The GABA content in brown rice was 14.06 mg/100 g in ‘47JB-4-B-5-B’and 6.8 mg/100 g in ‘wayoung’ Especially, the GABA content in brown rice of ‘47JB-4-B-5-B’remarkably increased (about 33 times from 1.48 mg to 44.81 mg/100 g) 2 days after germination. Continuous frequency distributions and transgressive segregation in embryo length and width were observed in the F 2 population of the cross between ‘47’and ‘heongcheong’ indicating that the giant embryo was controlled by quantitative trait loci. However, embryo length and width demonstrated high broad sense heritability, implying that giant embryonic traits could be selected in earlier generations in comparison with other quantitative traits.