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1.
Adv Exp Med Biol ; 1261: 95-113, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33783733

RESUMO

Multi-gene transformation methods need to be able to introduce multiple transgenes into plants in order to reconstitute a transgenic locus where the introduced genes express in a coordinated manner and do not segregate in subsequent generations. This simultaneous multiple gene transfer enables the study and modulation of the entire metabolic pathways and the elucidation of complex genetic control circuits and regulatory hierarchies. We used combinatorial nuclear transformation to produce multiplex-transgenic maize plants. In proof of principle experiments, we co-expressed five carotenogenic genes in maize endosperm. The resulting combinatorial transgenic maize plant population, equivalent to a "mutant series," allowed us to identify and complement rate-limiting steps in the extended endosperm carotenoid pathway and to recover corn plants with extraordinary levels of ß-carotene and other nutritionally important carotenoids. We then introgressed the induced (transgenic) carotenoid pathway in a transgenic line accumulating high levels of nutritionally important carotenoids into a wild-type yellow-endosperm variety with a high ß:ε ratio. Novel hybrids accumulated zeaxanthin at unprecedented amounts. We introgressed the same pathway into a different yellow corn line with a low ß:ε ratio. The resulting hybrids, in this case, had a very different carotenoid profile. The role of genetic background in determining carotenoid profiles in corn was elucidated, and further rate-limiting steps in the pathway were identified and resolved in hybrids. Astaxanthin accumulation was engineered by overexpression of a ß-carotene ketolase in maize endosperm. In early experiments, limited astaxanthin accumulation in transgenic maize plants was attributed to a bottleneck in the conversion of adonixanthin (4-ketozeaxanthin) to astaxanthin. More recent experiments showed that a synthetic ß-carotene ketolase with a superior ß-carotene/zeaxanthin ketolase activity is critical for the high-yield production of astaxanthin in maize endosperm. Engineered lines were used in animal feeding experiments which demonstrated not only the safety of the engineered lines but also their efficacy in a range of different animal production applications.


Assuntos
Endosperma , Zea mays , Animais , Carotenoides/metabolismo , Endosperma/genética , Endosperma/metabolismo , Redes e Vias Metabólicas , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Zea mays/genética , Zea mays/metabolismo
2.
J Dairy Sci ; 104(2): 1794-1810, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33309382

RESUMO

Kernel processing and theoretical length of cut (TLOC) of whole-plant corn silage (WPCS) can affect feed intake, digestibility, and performance of dairy cows. The objective of this study was to evaluate for lactating dairy cows the effects of kernel processing and TLOC of WPCS with vitreous endosperm. The treatments were a pull-type forage harvester without kernel processor set for a 6-mm TLOC (PT6) and a self-propelled forage harvester with kernel processor set for a 6-mm TLOC (SP6), 12-mm TLOC (SP12), and 18-mm TLOC (SP18). Processing scores of the WPCS were 32.1% (PT6), 53.9% (SP6), 49.0% (SP12), and 40.1% (SP18). Twenty-four Holstein cows (139 ± 63 d in milk) were blocked and assigned to six 4 × 4 Latin squares with 24-d periods (18 d of adaptation). Diets were formulated to contain 48.5% WPCS, 15.5% citrus pulp, 15.0% dry ground corn, 9.5% soybean meal, 6.8% low rumen degradability soybean meal, 1.8% calcium soap of palm fatty acids (FA), 1.7% mineral and vitamin mix, and 1% urea (dry matter basis). Nutrient composition of the diets (% of dry matter) was 16.5% crude protein, 28.9% neutral detergent fiber, and 25.4% starch. Three orthogonal contrasts were used to compare treatments: effect of kernel processing (PT6 vs. SP6) and effect of TLOC (particle size; SP6 vs. SP12 and SP12 vs. SP18). Cows fed SP6 produced 1.2 kg/d greater milk yield with no changes in dry matter intake, resulting in greater feed efficiency compared with PT6. Cows fed SP6 also produced more milk protein (+36 g/d), lactose (+61 g/d), and total solids (+94 g/d) than cows fed PT6. The mechanism for increased yield of milk and milk components involved greater kernel fragmentation, starch digestibility, and glucose availability for lactose synthesis by the mammary gland. However, cows fed SP6 had lower chewing time and tended to have greater levels of serum amyloid A compared with PT6. Milk yield was similar for SP6 and SP12, but SP12 cows tended to have less serum amyloid A with greater chewing time. Cows fed SP18 had lower total-tract starch digestibility and tended to have lower plasma glucose and produce less milk compared with cows fed SP12. Compared with PT6, feeding SP6 raised linear odd-chain FA concentration in milk. Similarly, a reduction of these same FA occurred for SP12 compared with SP6. Cows fed SP6 had greater proportion of milk C14:1 and C16:1 compared with PT6 and SP12. Lesser trans C18:1 followed by greater C18:0 concentrations were observed for SP12 and PT6 compared with SP6, which is an indication of more complete biohydrogenation in the rumen. Under the conditions of this study, the use of a self-propelled forage harvester with kernel processing set for a 12-mm TLOC is recommended for WPCS from hybrids with vitreous endosperm.


Assuntos
Bovinos/fisiologia , Endosperma/metabolismo , Manipulação de Alimentos/métodos , Silagem/análise , Zea mays/metabolismo , Animais , Fibras na Dieta/metabolismo , Ingestão de Alimentos , Feminino , Lactação/fisiologia , Lactose/metabolismo , Leite/química , Leite/metabolismo , Proteínas do Leite/metabolismo , Tamanho da Partícula , Rúmen/metabolismo , Amido/metabolismo
3.
Nat Commun ; 11(1): 5346, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-33093471

RESUMO

The mechanism that creates vitreous endosperm in the mature maize kernel is poorly understood. We identified Vitreous endosperm 1 (Ven1) as a major QTL influencing this process. Ven1 encodes ß-carotene hydroxylase 3, an enzyme that modulates carotenoid composition in the amyloplast envelope. The A619 inbred contains a nonfunctional Ven1 allele, leading to a decrease in polar and an increase in non-polar carotenoids in the amyloplast. Coincidently, the stability of amyloplast membranes is increased during kernel desiccation. The lipid composition in endosperm cells in A619 is altered, giving rise to a persistent amyloplast envelope. These changes impede the gathering of protein bodies and prevent them from interacting with starch grains, creating air spaces that cause an opaque kernel phenotype. Genetic modifiers were identified that alter the effect of Ven1A619, while maintaining a high ß-carotene level. These studies provide insight for breeding vitreous kernel varieties and high vitamin A content in maize.


Assuntos
Carotenoides/metabolismo , Zea mays/metabolismo , Alelos , Mapeamento Cromossômico , Cruzamentos Genéticos , Endosperma/genética , Endosperma/metabolismo , Endosperma/ultraestrutura , Genes de Plantas , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Fenótipo , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/genética , Plastídeos/metabolismo , Plastídeos/ultraestrutura , Locos de Características Quantitativas , Sementes/genética , Sementes/metabolismo , Sementes/ultraestrutura , Zea mays/genética , Zea mays/ultraestrutura
4.
Food Chem ; 330: 127318, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569935

RESUMO

The objective of this study was to determine the biophysical properties of buckwheat (BW) endosperm and their influences on detachment of intact cells, starch gelatinization and digestibility. The intact cells were isolated from BW kernels by dry milling and sieving. The microscopy and texture analysis showed intact endosperm cells could be detached easily due to the fragile structure and low hardness of BW endosperm. More than 70% intact cells were found in commercial light flour. The starch granules entrapped in intact cells exhibited a delay gelatinization and restricted swelling behavior (2-3 â„ƒ higher onset gelatinization temperature than isolated starch). Starch in BW flour had a markedly lower extent of digestion compared to the broken cells and isolated starch. This study provided a new mechanistic understanding of low glycemic index of BW food, and could guide the processing of BW flour to retain slow digestion properties.


Assuntos
Endosperma/citologia , Fagopyrum/citologia , Fagopyrum/metabolismo , Farinha , Amido/farmacocinética , Culinária , Digestão , Endosperma/química , Endosperma/metabolismo , Fagopyrum/química , Farinha/análise , Gelatina , Índice Glicêmico , Tamanho da Partícula , Células Vegetais/química , Células Vegetais/metabolismo , Amido/química , Temperatura
5.
Food Chem ; 326: 126845, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32438226

RESUMO

Dry cultivation of high-yielding or drought-resistant rice cultivars relieves the current pressure on rice cultivation systems. However, the metabolites and metabolic pathways that affect rice quality in high-yield or drought-resistant rice cultivars under dry cultivation have not yet been explored. A field experiment was conducted in 2017 to explore the effects of flooding irrigation (F) and dry cultivation (D) of high-yield and -quality cultivars (Huanghuazhan, HH; Yueyou9113, YY) and a drought-resistant cultivar (Hanyou73, HY) on rice quality traits using metabolomic analysis. Treatment DHH maintained higher head rice yield, amylose content, protein content, and breakdown values and a lower whiteness index and setback value than other cultivars under dry cultivation. These rice quality traits were related to 16 metabolites and 8 metabolic pathways. DHH showed decreases in stress response metabolites (m72, m98, m127, m165, m167, m213, m297, and m298) but maintained stress resistance (m29, m30, m39, m48, and m58) and sucrose (m150) accumulation in grains to support head rice yields and a low whiteness index. Raising the lactose, choline, and nicotinoylcholine levels in rice grains improved their protein content and cooking quality. DHH also adjusted the glycine, serine and threonine metabolism, galactose metabolism, and starch and sucrose metabolism of rice. This affected the biosynthesis of anthocyanin, phenylpropanoid, and flavonoid, supporting protein biosynthesis and starch accumulation in the endosperm. These findings provide further possibilities for improving rice quality traits of high-yield and -quality rice cultivars under dry cultivation.


Assuntos
Grão Comestível/metabolismo , Oryza/metabolismo , Amilose/metabolismo , Culinária , Secas , Endosperma/metabolismo , Metabolômica , Amido/metabolismo
6.
Plant Mol Biol ; 103(4-5): 457-471, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32274640

RESUMO

KEY MESSAGE: In this manuscript, we disclosed the influence of light on the accumulation of storage reserves in B. napus embryos.1.Light induced the gene expression in the developing embryos of B. napus.2.Light promoted the starch synthesis in chloroplasts of B. napus embryos.3.Light enhanced the metabolic activity of storage reserve synthesis in B. napus embryos. Light influences the accumulation of storage reserves in embryos, but the molecular mechanism was not fully understood. Here, we monitored the effects of light on reserve biosynthesis in Brassica napus by comparing embryos from siliques grown in normal light conditions to those that were shaded or masked (i.e., darkened completely). Masked embryos developed more slowly, weighed less, and contained fewer proteins and lipids than control embryos. They also had fewer and smaller oil bodies than control embryos and lacked chloroplasts, where starch grains are usually synthesized. The levels of most amino acids, carbohydrates, and fatty acids were higher in masked embryos than in control or shaded embryos, whereas the levels of these metabolites in the masked endosperms were lower than those in control and shaded endosperm. Transcriptome analysis indicated that genes involved in photosynthesis (42 genes), amino acid biosynthesis (51 genes), lipid metabolism (61 genes), and sugar transport (13 genes) were significantly repressed in masked embryos. Our results suggest that light contributes to reserve accumulation in embryos by inducing the expression of metabolic genes, thereby enhancing the biosynthesis of storage reserves.


Assuntos
Brassica napus/embriologia , Brassica napus/genética , Brassica napus/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Sementes/genética , Sementes/efeitos da radiação , Aminoácidos/metabolismo , Brassica napus/crescimento & desenvolvimento , Metabolismo dos Carboidratos , Clorofila/análise , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Endosperma/metabolismo , Endosperma/efeitos da radiação , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica , Metabolismo dos Lipídeos , Fotossíntese , Óleos Vegetais/metabolismo , Proteínas de Plantas/genética , Sementes/citologia , Sementes/crescimento & desenvolvimento , Amido/biossíntese , Transcriptoma
7.
Proc Natl Acad Sci U S A ; 117(11): 6231-6236, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32132210

RESUMO

Double fertilization is a key innovation for the evolutionary success of angiosperms by which the two fertilized female gametes, the egg cell and central cell, generate the embryo and endosperm, respectively. The female gametophyte (embryo sac) enclosed in the sporophyte is derived from a one-celled haploid cell lineage. It undergoes successive events of mitotic divisions, cellularization, and cell specification to give rise to the mature embryo sac, which contains the two female gametes accompanied by two types of accessory cells, namely synergids and antipodals. How the cell fate of the central cell is specified has long been equivocal and is further complicated by the structural diversity of female gametophyte across plant taxa. Here, MADS-box protein AGL80 was verified as a transcriptional repressor that directly suppresses the expression of accessory cell-specific genes to specify the central cell. Further genetic rescue and phylogenetic assay of the AGL80 orthologs revealed a possible conserved mechanism in the Brassicaceae family. Results from this study provide insight into the molecular determination of the second female gamete cell in Brassicaceae.


Assuntos
Proteína AGAMOUS de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Óvulo Vegetal/genética , Transcrição Genética , Proteína AGAMOUS de Arabidopsis/genética , Proteínas de Arabidopsis/genética , Endosperma/metabolismo , Fertilização/genética , Mutação , Filogenia , Plantas Geneticamente Modificadas , Fatores de Transcrição/genética
8.
Plant Biol (Stuttg) ; 22(4): 669-678, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32141171

RESUMO

A significant asynchronous phenomenon exists in super hybrid rice because of the differences in spike and spikelet positions, which affect the accumulation and properties of starch. However, little is known about the endosperm enrichment and physicochemical properties of starch in superior and inferior grains in super hybrid rice. Rice YY2640 was selected as study material to investigate the enrichment and physicochemical properties of starch in superior and inferior grains in super rice using semi-thin sections, X-ray diffraction and related technologies. Superior grain filling was a continuous process, whereas inferior grain only started 8-10 days after anthesis. The order of starch accumulation starts in the central endosperm, then in the endosperm of the proximal vascular bundle and finally in the aleurone layer. Compared with the inferior grains, the superior grains have a higher 1000-grain weight, apparent amylose content, total starch content, average starch granule size, relative crystallinity, solubility and a resonance peak ratio at 1022/995 cm-1 , whereas the swelling power and ratio of the resonance peak at 1045/1022 cm-1 were lower. The final degree of hydrolysis of HCl, AAG and PPA of the superior grains were significantly lower than those of the inferior grains. The findings indicate that the different physicochemical properties of starch were mainly related to the development order of superior and inferior grains and the spatial enrichment of starch.


Assuntos
Endosperma , Oryza , Amido , Amilose/metabolismo , Grão Comestível/química , Grão Comestível/genética , Grão Comestível/metabolismo , Endosperma/metabolismo , Oryza/química , Oryza/genética , Oryza/metabolismo , Amido/metabolismo
9.
Int J Mol Sci ; 21(4)2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32085665

RESUMO

Absence of high-molecular-weight glutenin subunit (HMW-GS) Dx2 weakens the gluten quality, but it is unclear how the absence of Dx2 has these effects. Thus, we investigated the gluten quality in terms of cytological, physicochemical, and transcriptional characteristics using two near-isogenic lines with Dx2 absent or present at Glu-D1 locus. Cytological observations showed that absence of Dx2 delayed and decreased the accumulation of protein bodies (PBs), where fewer and smaller PBs formed in the endosperm. The activity and gene expression levels of nitrogen assimilation and proteolysis enzymes were lower in HMW-D1a without Dx2 than HMW-D1p with Dx2, and thus less amino acid was transported for protein synthesis in the grains. The expression pattern of genes encoding Glu-1Dx2+1Dy12 was similar to those of three transcription factors, where these genes were significantly down-regulated in HMW-D1a than HMW-D1p. Three genes involving with glutenin polymerization were also down-regulated in HMW-D1a. These results may explain the changes in the glutenin and glutenin macropolymer (GMP) levels during grain development. Therefore, we suggest that the lower nitrogen metabolism capacity and expression levels of glutenin synthesis-related genes in HMW-D1a accounted for the lower accumulation of glutenin, GMP, and PBs, thereby weakening the structural‒thermal properties of gluten.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Loci Gênicos , Glutens/genética , Nitrogênio/metabolismo , Triticum/genética , Aminoácidos/metabolismo , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Glutamato-Amônia Ligase/metabolismo , Glutens/biossíntese , Glutens/química , Glutens/metabolismo , Folhas de Planta/metabolismo , Polimerização , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Temperatura , Transaminases/metabolismo , Transcrição Genética
10.
BMC Plant Biol ; 20(1): 48, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000683

RESUMO

BACKGROUND: Little is known about the molecular basis of seed size formation in endospermic seed of dicotyledons. The seed of castor bean (Ricinus communis L.) is considered as a model system in seed biology studies because of its persistent endosperms throughout seed development. RESULTS: We compared the size of endosperm and endospermic cells between ZB107 and ZB306 and found that the larger seed size of ZB107 resulted from a higher cell count in the endosperm, which occupy a significant amount of the total seed volume. In addition, fresh weight, dry weight, and protein content of seeds were remarkably higher in ZB107 than in ZB306. Comparative proteomic and transcriptomic analyses were performed between large-seed ZB107 and small-seed ZB306, using isobaric tags for relative and absolute quantification (iTRAQ) and RNA-seq technologies, respectively. A total of 1416 protein species were identified, of which 173 were determined as differentially abundant protein species (DAPs). Additionally, there were 9545 differentially expressed genes (DEGs) between ZB306 and ZB107. Functional analyses revealed that these DAPs and DEGs were mainly involved in cell division and the metabolism of carbohydrates and proteins. CONCLUSIONS: These findings suggest that both cell number and storage-component accumulation are critical for the formation of seed size, providing new insight into the potential mechanisms behind seed size formation in endospermic seeds.


Assuntos
Semente de Rícino/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Sementes/crescimento & desenvolvimento , Transcriptoma , Semente de Rícino/genética , Semente de Rícino/metabolismo , Endosperma/genética , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Perfilação da Expressão Gênica , Proteômica , Sementes/genética , Sementes/metabolismo
11.
Plant Biotechnol J ; 18(9): 1897-1907, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32004404

RESUMO

The endosperm-specific transcription factor Opaque2 (O2) acts as a central regulator for endosperm filling, but its functions have not been fully defined. Regular o2 mutants exhibit a non-vitreous phenotype, so we used its vitreous variety Quality Protein Maize to create EMS-mutagenesis mutants for screening o2 enhancers (oen). A mutant (oen1) restored non-vitreousness and produced a large cavity in the seed due to severely depleted endosperm filling. When oen1 was introgressed into inbred W64A with a normal O2 gene, the seeds appeared vitreous but had a shrunken crown. oen1 was determined to encode Shrunken1 (Sh1), a sucrose synthase (SUS, EC 2.4.1.13). Maize contains three SUS-encoding genes (Sh1, Sus1, and Sus2) with Sh1 contributing predominantly to the endosperm. We determined SUS activity and found a major and minor reduction in oen1 and o2, respectively. In o2;oen1-1, SUS activity was further decreased. We found all Sus gene promoters contain at least one O2 binding element that can be specifically recognized and be transactivated by O2. Sus1 and Sus2 promoters had a much stronger O2 transactivation than Sh1, consistent with their transcript reduction in o2 endosperm. Although sus1 and sus2 alone or in combination had no perceptible phenotype, either of them could dramatically enhance seed opacity and cavity in sh1, indicating that transactivation of Sus1 and Sus2 by O2 supplements SUS-mediated endosperm filling in maize. Our findings demonstrate that O2 transcriptionally regulates the metabolic source entry for protein and starch synthesis during endosperm filling.


Assuntos
Endosperma , Zea mays , Endosperma/genética , Endosperma/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Ativação Transcricional/genética , Zea mays/genética , Zea mays/metabolismo
12.
Sci Rep ; 10(1): 1864, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024857

RESUMO

Cereal endosperm is a short-lived tissue adapted for nutrient storage, containing specialized organelles, such as protein bodies (PBs) and protein storage vacuoles (PSVs), for the accumulation of storage proteins. During development, protein trafficking and storage require an extensive reorganization of the endomembrane system. Consequently, endomembrane-modifying proteins will influence the final grain quality and yield. However, little is known about the molecular mechanism underlying endomembrane system remodeling during barley grain development. By using label-free quantitative proteomics profiling, we quantified 1,822 proteins across developing barley grains. Based on proteome annotation and a homology search, 94 proteins associated with the endomembrane system were identified that exhibited significant changes in abundance during grain development. Clustering analysis allowed characterization of three different development phases; notably, integration of proteomics data with in situ subcellular microscopic analyses showed a high abundance of cytoskeleton proteins associated with acidified PBs at the early development stages. Moreover, endosomal sorting complex required for transport (ESCRT)-related proteins and their transcripts are most abundant at early and mid-development. Specifically, multivesicular bodies (MVBs), and the ESCRT-III HvSNF7 proteins are associated with PBs during barley endosperm development. Together our data identified promising targets to be genetically engineered to modulate seed storage protein accumulation that have a growing role in health and nutritional issues.


Assuntos
Citoesqueleto/metabolismo , Endosperma/metabolismo , Endosperma/fisiologia , Hordeum/metabolismo , Hordeum/fisiologia , Proteínas de Plantas/metabolismo , Transporte Proteico/fisiologia , Grão Comestível/metabolismo , Grão Comestível/fisiologia , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Perfilação da Expressão Gênica/métodos , Corpos Multivesiculares/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Vacúolos/metabolismo , Vacúolos/fisiologia
13.
Science ; 367(6476): 431-435, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31974252

RESUMO

The plant embryonic cuticle is a hydrophobic barrier deposited de novo by the embryo during seed development. At germination, it protects the seedling from water loss and is, thus, critical for survival. Embryonic cuticle formation is controlled by a signaling pathway involving the ABNORMAL LEAF SHAPE1 subtilase and the two GASSHO receptor-like kinases. We show that a sulfated peptide, TWISTED SEED1 (TWS1), acts as a GASSHO ligand. Cuticle surveillance depends on the action of the subtilase, which, unlike the TWS1 precursor and the GASSHO receptors, is not produced in the embryo but in the neighboring endosperm. Subtilase-mediated processing of the embryo-derived TWS1 precursor releases the active peptide, triggering GASSHO-dependent cuticle reinforcement in the embryo. Thus, a bidirectional molecular dialogue between embryo and endosperm safeguards cuticle integrity before germination.


Assuntos
Endosperma/fisiologia , Germinação , Sementes/fisiologia , Sequência de Aminoácidos , Endosperma/citologia , Endosperma/metabolismo , Ligantes , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Sementes/citologia , Sementes/metabolismo , Serina Endopeptidases/química , Serina Endopeptidases/metabolismo , Transdução de Sinais , Tabaco/crescimento & desenvolvimento , Tabaco/metabolismo
14.
Int J Mol Sci ; 21(2)2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952322

RESUMO

Cellular autophagy is a widely-occurring conserved process for turning over damaged organelles or recycling cytoplasmic contents in cells. Although autophagy-related genes (ATGs) have been broadly identified from many plants, little is known about the potential function of autophagy in mediating plant growth and development, particularly in recycling cytoplasmic contents during seed development and germination. Castor bean (Ricinus communis) is one of the most important inedible oilseed crops. Its mature seed has a persistent and large endosperm with a hard and lignified seed coat, and is considered a model system for studying seed biology. Here, a total of 34 RcATG genes were identified in the castor bean genome and their sequence structures were characterized. The expressional profiles of these RcATGs were examined using RNA-seq and real-time PCR in a variety of tissues. In particular, we found that most RcATGs were significantly up-regulated in the later stage of seed coat development, tightly associated with the lignification of cell wall tissues. During seed germination, the expression patterns of most RcATGs were associated with the decomposition of storage oils. Furthermore, we observed by electron microscopy that the lipid droplets were directly swallowed by the vacuoles, suggesting that autophagy directly participates in mediating the decomposition of lipid droplets via the microlipophagy pathway in germinating castor bean seeds. This study provides novel insights into understanding the potential function of autophagy in mediating seed development and germination.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Semente de Rícino/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Genômica/métodos , Autofagia/genética , Proteínas Relacionadas à Autofagia/classificação , Proteínas Relacionadas à Autofagia/metabolismo , Semente de Rícino/metabolismo , Óleo de Rícino/metabolismo , Endosperma/genética , Endosperma/metabolismo , Germinação/genética , Sequenciamento de Nucleotídeos em Larga Escala , Gotículas Lipídicas/metabolismo , Filogenia , Sementes/genética , Sementes/metabolismo
15.
Carbohydr Polym ; 230: 115656, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887861

RESUMO

How various isoforms of rice-starch biosynthesis enzymes interact during amylose and amylopectin synthesis is explored. The chain-length distributions of amylopectin and amylose from 95 varieties with different environmental and genetic backgrounds were obtained using size- exclusion chromatography, and fitted with biosynthesis-derived models based on isoforms of starch synthase (SSI-SSIV), starch branching enzyme (SBE, including SBEI and SBEII) and granule-bound starch synthase (GBSS) that are involved in amylose and amylopectin synthesis. It is usually thought that these are synthesized by separate enzymes. However, the amount of longer amylopectin chains correlated with that of shorter amylose chains, indicating that GBSS, SBE and SS affect both amylose and amylopectin synthesis. Further, the activity of GBSS in amylose correlated with that of SS in amylopectin. This new understanding of which enzymes are suggested by the statistics to be involved in both amylose and amylopectin synthesis could help rice breeders develop cereals with targeted properties.


Assuntos
Amilopectina/biossíntese , Amilose/biossíntese , Endosperma/metabolismo , Oryza/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucana/química , Grão Comestível/metabolismo , Proteínas de Plantas/química , Sintase do Amido/química
16.
Plant Sci ; 291: 110336, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928684

RESUMO

Wheat grain nitrogen content displays large variations within different pearling fractions of grains because of radial gradients in the protein content. We identified how spatiotemporal mechanisms regulate this. The protein gradients emerged clearly at 19 days after anthesis, with the highest N content in aleurone and seed coat, followed by outer endosperm, whereas the lowest was in middle and inner endosperm. Laser microdissection, qRT-PCR and LC-MS were used to dissect tissue from aleurone, outer endosperm, middle endosperm, inner endosperm and transfer cells, measure gene expression and levels of free and protein-bound amino acids, respectively. The results showed that different FAA transportation pathways worked in parallel during grain filling stage while the grain protein gradient did not follow spatial expression of storage proteins. Additionally, two nitrogen (N) topdressing timings were conducted, either at the emergence of top third leaf (standard timing) or top first leaf (delayed timing), finding that delayed N topdressing enhanced both amino acids supply and protein synthesis capacity. The results provide insight into protein synthesis and amino acid transport pathways in endosperm and suggest targets for the enhancement of specialty pearled wheat with higher quality.


Assuntos
Aminoácidos/metabolismo , Endosperma/química , Proteínas de Plantas/metabolismo , Sementes/química , Triticum/genética , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Triticum/química , Triticum/metabolismo
17.
J Plant Physiol ; 245: 153109, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31896032

RESUMO

OsERdj7 is one of six endoplasmic reticulum (ER)-resident J-domain-containing proteins (J-proteins) encoded by the rice genome that acts as a co-chaperone for Hsp70 and is characterized by the presence of two transmembrane domains. It is N-glycosylated and primarily exists in a dimeric form with a molecular mass of 64 kDa. When the microsomal fraction of maturing seeds was treated with alkaline, high salt or detergent compounds, OsERdj7 was solubilized, even in alkaline and high salt environments, indicating that it is not tightly integrated in the ER membrane. Next, to investigate its role during seed maturation, expression of OsERdj7 was specifically downregulated using RNA interference (RNAi) under the control of the endosperm-specific 16 kDa prolamin promoter in transgenic rice. As a result, the unfolded protein response (UPR) was induced in maturing seeds via activation of OsIRE1/OsbZIP50 and ATF6 orthologs, such as OsbZIP39 and OsbZIP60, leading to upregulation of several chaperones and folding enzymes. Furthermore, some prolamins (RM4 and RM9) were retained in the ER lumen in the form of a mesh-like structure without deposition to the inherent ER-derived protein bodies (PB-Is), although major storage protein glutelins were normally transported to protein storage vacuoles (PB-IIs). On the other hand, induction of ER associated degradation (ERAD) increased OsERdj7 expression in transgenic rice seeds in which ERAD related genes were highly expressed. Due to PDIL2-3 and OsHard3 co-immunoprecipitating with OsERdj7 in rice protoplasts, this result implicates OsERdj7 in the translocation of some seed proteins within the ER lumen and in the degradation of misfolded or unfolded proteins.


Assuntos
Estresse do Retículo Endoplasmático/genética , Degradação Associada com o Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Endosperma/metabolismo , Chaperonas Moleculares/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Fator 6 Ativador da Transcrição/genética , Fator 6 Ativador da Transcrição/metabolismo , Endosperma/enzimologia , Endosperma/genética , Regulação da Expressão Gênica de Plantas/genética , Glutens/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Oryza/genética , Plantas Geneticamente Modificadas/genética , Prolaminas/metabolismo , Domínios Proteicos , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Vacúolos/metabolismo
18.
Plant Mol Biol ; 102(1-2): 225-237, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820284

RESUMO

KEY MESSAGE: The specific and high-level expression of 1Ax1 is determined by different promoter regions. HMW-GS synthesis occurs in aleurone layer cells. Heterologous proteins can be stored in protein bodies. High-molecular-weight glutenin subunit (HMW-GS) is highly expressed in the endosperm of wheat and relative species, where their expression level and allelic variation affect the bread-making quality and nutrient quality of flour. However, the mechanism regulating HMW-GS expression remains elusive. In this study, we analyzed the distribution of cis-acting elements in the 2659-bp promoter region of the HMW-GS gene 1Ax1, which can be divided into five element-enriched regions. Fragments derived from progressive 5' deletions were used to drive GUS gene expression in transgenic wheat, which was confirmed in aleurone layer cells, inner starchy endosperm cells, starchy endosperm transfer cells, and aleurone transfer cells by histochemical staining. The promoter region ranging from - 297 to - 1 was responsible for tissue-specific expression, while fragments from - 1724 to - 618 and from - 618 to - 297 were responsible for high-level expression. Under the control of the 1Ax1 promoter, heterologous protein could be stored in the form of protein bodies in inner starchy endosperm cells, even without a special location signal. Our findings not only deepen our understanding of glutenin expression regulation, trafficking, and accumulation but also provide a strategy for the utilization of wheat endosperm as a bioreactor for the production of nutrients and metabolic products.


Assuntos
Evolução Biológica , Regulação da Expressão Gênica de Plantas , Glutens/biossíntese , Glutens/genética , Regiões Promotoras Genéticas/genética , Triticum/genética , Pão , Endosperma/metabolismo , Farinha , Genes de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Subunidades Proteicas/biossíntese , Subunidades Proteicas/genética , Amido/metabolismo
19.
Sci Rep ; 9(1): 18544, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811157

RESUMO

Autophagy plays crucial roles in the recycling of metabolites, and is involved in many developmental processes. Rice mutants defective in autophagy are male sterile due to immature pollens, indicating its critical role in pollen development. However, physiological roles of autophagy during seed maturation had remained unknown. We here found that seeds of the rice autophagy-deficient mutant Osatg7-1, that produces seeds at a very low frequency in paddy fields, are smaller and show chalky appearance and lower starch content in the endosperm at the mature stage under normal growth condition. We comprehensively analyzed the effects of disruption of autophagy on biochemical properties, proteome and seed quality, and found an abnormal activation of starch degradation pathways including accumulation of α-amylases in the endosperm during seed maturation in Osatg7-1. These results indicate critical involvement of autophagy in metabolic regulation in the endosperm of rice, and provide insights into novel autophagy-mediated regulation of starch metabolism during seed maturation.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Autofagia/fisiologia , Endosperma/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas Relacionadas à Autofagia/metabolismo , Endosperma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Mutação , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Amido/metabolismo , Regulação para Cima , alfa-Amilases/genética , alfa-Amilases/metabolismo
20.
Sci Rep ; 9(1): 18567, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811177

RESUMO

In the recent time, Submergence1 (Sub1)QTL, responsible for imparting tolerance to flash flooding, has been introduced in many rice cultivars, but resilience of the QTL to stagnant flooding (SF) is not known. The response of Sub1-introgression has been tested on physiology, molecular biology and yield of two popular rice cultivars (Swarna and Savitri) by comparison of the parental and Sub1-introgression lines (SwarnaSub1 and SavitriSub1) under SF. Compared to control condition SF reduced grain yield and tiller number and increased plant height and Sub1- introgression mostly matched these effects. SF increased ethylene production by over-expression of ACC-synthase and ACC-oxidase enzyme genes of panicle before anthesis in the parental lines. Expression of the genes changed with Sub1-introgression, where some enzyme isoform genes over-expressed after anthesis under SF. Activities of endosperm starch synthesizing enzymes SUS and AGPase declined concomitantly with rise ethylene production in the Sub1-introgressed lines resulting in low starch synthesis and accumulation of soluble carbohydrates in the developing spikelets. In conclusion, Sub1-introgression into the cultivars increased susceptibility to SF. Subjected to SF, the QTL promoted genesis of ethylene in the panicle at anthesis to the detriment of grain yield, while compromising with morphological features like tiller production and stem elongation.


Assuntos
Etilenos/biossíntese , Genes de Plantas/genética , Introgressão Genética , Oryza/fisiologia , Locos de Características Quantitativas , Adaptação Fisiológica/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Inundações , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/biossíntese , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Amido/biossíntese
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