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1.
J Genet ; 1002021.
Artigo em Inglês | MEDLINE | ID: mdl-34553697

RESUMO

The Waxy locus of rice is a highly polymorphic region embedded with microsatellite repeats in the 5'UTR leader intron 1 region, 23-bp duplication (wx motif) in exon 2, SNPs in exons 4, 6 and 10, p-Sine-r2 element in intron 1 and TnR-1 element in inton 13. Of the 80 polymorphic sites detected on the Wx gene, 24 are located in p-Sine-r2 and TnR-1 elements, revealing a higher substitution rate of bases in these two regions. All the cultivars with chalky endosperm had the 5'-AGTTATA-3' haplotype in intron 1 and 'A' to 'G' substitution at ?497 in exon 4. The AAC of starch from grains of all the accessions showed strong correlation (r=0.967) with GBSS-I activity in the grains. Based on the polymorphic sites of the Waxy locus and the GBSS-I activities, six allelic variants were defined which included wx, Wxop, Wxb, Wxin, Wxa2 and Wxa1, respectively, corresponded to glutinous, very low, low, intermediate, highII and highI amylose classes. Phylogenetic tree developed from alignment matrix of nucleotide sequences of the Waxy locus identified wx, Wxb and Wxin alleles with japonica lineage of Oryza sativa and the Wxop, Wxa2 and Wxa1 with indica lineage.


Assuntos
Alelos , Amilose/metabolismo , Domesticação , Oryza/genética , Amido/metabolismo , Sequência de Bases , Regulação da Expressão Gênica de Plantas , Loci Gênicos , Repetições de Microssatélites/genética , Modelos Moleculares , Motivos de Nucleotídeos/genética , Oryza/enzimologia , Filogenia , Polimorfismo Genético , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/anatomia & histologia , Sementes/genética , Sintase do Amido/química , Sintase do Amido/genética , Sintase do Amido/metabolismo
2.
J Plant Physiol ; 264: 153484, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34343729

RESUMO

High concentrations of As in contaminated environments pose a serious threat to plant, human, and animal health. In this study, we characterized an As-responsive Really Interesting New Gene (RING) E3 ubiquitin ligase gene under arsenate (AsV) stress, named as Oryza sativa As-Induced RING E3 ligase 3 (OsAIR3). AsV treatment highly induced the expression of OsAIR3. OsAIR3-EYFP was localized to the nucleus in rice protoplasts and exhibited E3 ligase activity. Yeast two-hybrid screening and bimolecular fluorescence complementation and pull-down assays revealed the interaction of OsAIR3 with an O. sativa molybdate transporter (OsMOT1;3) in the plasma membrane and cytoplasm. In addition, an in vitro cell-free degradation assay was performed to demonstrate the degradation of OsMOT1;3 by OsAIR3 via the 26S proteasome system. Heterogeneous overexpression of OsAIR3 in Arabidopsis yielded AsV-tolerant phenotypes, as indicated by the comparison of cotyledon expansion, root elongation, shoot fresh weight, and As accumulation between the OsAIR3-overexpressing and control plants. Collectively, these findings suggest that OsAIR3 positively regulates plant response to AsV stress.


Assuntos
Proteínas de Transporte/metabolismo , Molibdênio/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Arsênio/toxicidade , Oryza/enzimologia , Transcriptoma , Técnicas do Sistema de Duplo-Híbrido
3.
J Plant Physiol ; 264: 153482, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34330009

RESUMO

C4 plants are superior to C3 plants in terms of productivity and limited photorespiration. PPDK (pyruvate orthophosphate dikinase) and NADP-ME (NADP-dependent malic enzyme) are two important photosynthetic C4-specific enzymes present in the mesophyll cells of C4 plants. To evaluate the effect of C4 enzymes in rice, we developed transgenic rice lines by separately introducing Setaria italica PPDK [SiPPDK] and S. italica ME [SiME] gene constructs under the control of the green tissue-specific maize PPDK promoter. Rice plant lines for both constructs were screened using the polymerase chain reaction (PCR), Southern hybridization, and expression analysis. The best transgenic plant lines for each case were selected for physiological and biochemical characterization. The results from qRT-PCR and enzyme activity analysis revealed higher expression and activity of both PPDK and NADP-ME genes compared with the nontransformed and empty-vector-transformed plants. The average photosynthetic efficiency of transgenic plant lines carrying the PPDK and NADP-ME genes increased by 18% and 12%, respectively, and was positively correlated with the increased accumulation of photosynthetic pigment. The decrease in Fv/Fm, increased electron transport rate (ETR), and increased photochemical quenching (qP) compared with nontransformed control plants suggest that transgenic rice plants transferred more absorbed light energy to photochemical reactions than wild-type plants. SiME-transgenic plants displayed reduced leaf malate content and superior performance under water deficit conditions. Interestingly, the transgenic plants showed yield enhancement by exhibiting increased plant height, panicle length, panicle weight and thousand grain weight. Overall, the exogenous foxtail millet C4 gene PPDK enhanced photosynthesis and yield to a greater extent than NADP-ME.


Assuntos
Genes de Plantas/genética , Malato Desidrogenase/genética , Oryza/genética , Proteínas de Plantas/genética , Piruvato Ortofosfato Diquinase/genética , Setaria (Planta)/genética , Clorofila/metabolismo , Clonagem Molecular , Malato Desidrogenase/metabolismo , Oryza/anatomia & histologia , Oryza/enzimologia , Oryza/metabolismo , Fotossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/anatomia & histologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Piruvato Ortofosfato Diquinase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Setaria (Planta)/enzimologia , Setaria (Planta)/metabolismo
4.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299202

RESUMO

Rice spotted leaf mutants are helpful to investigate programmed cell death (PCD) and defense response pathways in plants. Using a map-based cloning strategy, we characterized novel rice spotted leaf mutation splHM143 that encodes a 7-hydroxymethyl chlorophyll a reductase (OsHCAR). The wild-type (WT) allele could rescue the mutant phenotype, as evidenced by complementation analysis. OsHCAR was constitutively expressed at all rice tissues tested and its expression products localized to chloroplasts. The mutant exhibited PCD and leaf senescence with increased H2O2 (hydrogen peroxide) accumulation, increased of ROS (reactive oxygen species) scavenging enzymes activities and TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling) -positive nuclei, upregulation of PCD related genes, decreased chlorophyll (Chl) contents, downregulation of photosynthesis-related genes, and upregulation of senescence-associated genes. Besides, the mutant exhibited enhanced bacterial blight resistance with significant upregulation of defense response genes. Knockout lines of OsHCAR exhibited spotted leaf phenotype, cell death, leaf senescence, and showed increased resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) coupled with upregulation of five pathogenesis-related marker genes. The overexpression of OsHCAR resulted in increased susceptibility to Xoo with decreased expression of pathogenesis-related marker genes. Altogether, our findings revealed that OsHCAR is involved in regulating cell death and defense response against bacterial blight pathogen in rice.


Assuntos
Resistência à Doença/imunologia , Oryza/imunologia , Oxirredutases/metabolismo , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/metabolismo , Xanthomonas/fisiologia , Clorofila/análogos & derivados , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Oxirredutases/genética , Doenças das Plantas/microbiologia , Folhas de Planta/enzimologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética
5.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299210

RESUMO

Conjugation of phytohormones with glucose is a means of modulating their activities, which can be rapidly reversed by the action of ß-glucosidases. Evaluation of previously characterized recombinant rice ß-glucosidases found that nearly all could hydrolyze abscisic acid glucose ester (ABA-GE). Os4BGlu12 and Os4BGlu13, which are known to act on other phytohormones, had the highest activity. We expressed Os4BGlu12, Os4BGlu13 and other members of a highly similar rice chromosome 4 gene cluster (Os4BGlu9, Os4BGlu10 and Os4BGlu11) in transgenic Arabidopsis. Extracts of transgenic lines expressing each of the five genes had higher ß-glucosidase activities on ABA-GE and gibberellin A4 glucose ester (GA4-GE). The ß-glucosidase expression lines exhibited longer root and shoot lengths than control plants in response to salt and drought stress. Fusions of each of these proteins with green fluorescent protein localized near the plasma membrane and in the apoplast in tobacco leaf epithelial cells. The action of these extracellular ß-glucosidases on multiple phytohormones suggests they may modulate the interactions between these phytohormones.


Assuntos
Ácido Abscísico/farmacologia , Ésteres/química , Glucose/metabolismo , Oryza/enzimologia , Proteínas de Plantas/metabolismo , beta-Glucosidase/metabolismo , Ácido Abscísico/química , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Secas , Giberelinas/farmacologia , Hidrólise , Família Multigênica , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Tabaco/efeitos dos fármacos , Tabaco/crescimento & desenvolvimento , Tabaco/metabolismo , beta-Glucosidase/genética
6.
Molecules ; 26(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204643

RESUMO

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.


Assuntos
Hidrolisados de Proteína/química , Hidrolisados de Proteína/farmacologia , Envelhecimento/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Clareadores/química , Clareadores/metabolismo , Flavonoides/farmacologia , Sequestradores de Radicais Livres/química , Ácido Gálico/farmacologia , Camundongos , Oryza/química , Oryza/enzimologia , Oryza/metabolismo , Oxirredução , Fenóis/farmacologia , Picratos/química , Picratos/farmacologia , Extratos Vegetais/química , Quercetina/farmacologia , Células RAW 264.7 , Ácidos Sulfônicos/química , Ácidos Sulfônicos/farmacologia , Tiazóis/química , Tiazóis/farmacologia
7.
BMC Plant Biol ; 21(1): 326, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229625

RESUMO

BACKGROUND: Glycolate oxidase (GLO) is not only a key enzyme in photorespiration but also a major engine for H2O2 production in plants. Catalase (CAT)-dependent H2O2 decomposition has been previously reported to be involved in the regulation of IAA biosynthesis. However, it is still not known which mechanism contributed to the H2O2 production in IAA regulation. RESULTS: In this study, we found that in glo mutants of rice, as H2O2 levels decreased IAA contents significantly increased, whereas high CO2 abolished the difference in H2O2 and IAA contents between glo mutants and WT. Further analyses showed that tryptophan (Trp, the precursor for IAA biosynthesis in the Trp-dependent biosynthetic pathway) also accumulated due to increased tryptophan synthetase ß (TSB) activity. Moreover, expression of the genes involved in Trp-dependent IAA biosynthesis and IBA to IAA conversion were correspondingly up-regulated, further implicating that both pathways contribute to IAA biosynthesis as mediated by the GLO-dependent production of H2O2. CONCLUSION: We investigated the function of GLO in IAA signaling in different levels from transcription, enzyme activities to metabolic levels. The results suggest that GLO-dependent H2O2 signaling, essentially via photorespiration, confers regulation over IAA biosynthesis in rice plants.


Assuntos
Oxirredutases do Álcool/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/enzimologia , Oxirredutases do Álcool/genética , Vias Biossintéticas/efeitos da radiação , Respiração Celular/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Modelos Biológicos , Mutação/genética , Oryza/genética , Oryza/efeitos da radiação , Peroxissomos/metabolismo , Peroxissomos/efeitos da radiação , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triptofano/metabolismo
8.
Int J Mol Sci ; 22(14)2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34299294

RESUMO

Nitrogen (N) is an essential nutrient for plant growth and development. The root system architecture is a highly regulated morphological system, which is sensitive to the availability of nutrients, such as N. Phenotypic characterization of roots from LY9348 (a rice variety with high nitrogen use efficiency (NUE)) treated with 0.725 mM NH4NO3 (1/4N) was remarkable, especially primary root (PR) elongation, which was the highest. A comprehensive analysis was performed for transcriptome and proteome profiling of LY9348 roots between 1/4N and 2.9 mM NH4NO3 (1N) treatments. The results indicated 3908 differential expression genes (DEGs; 2569 upregulated and 1339 downregulated) and 411 differential abundance proteins (DAPs; 192 upregulated and 219 downregulated). Among all DAPs in the proteome, glutamine synthetase (GS2), a chloroplastic ammonium assimilation protein, was the most upregulated protein identified. The unexpected concentration of GS2 from the shoot to the root in the 1/4N treatment indicated that the presence of an alternative pathway of N assimilation regulated by GS2 in LY9348 corresponded to the low N signal, which was supported by GS enzyme activity and glutamine/glutamate (Gln/Glu) contents analysis. In addition, N transporters (NRT2.1, NRT2.2, NRT2.3, NRT2.4, NAR2.1, AMT1.3, AMT1.2, and putative AMT3.3) and N assimilators (NR2, GS1;1, GS1;2, GS1;3, NADH-GOGAT2, and AS2) were significantly induced during the long-term N-deficiency response at the transcription level (14 days). Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that phenylpropanoid biosynthesis and glutathione metabolism were significantly modulated by N deficiency. Notably, many transcription factors and plant hormones were found to participate in root morphological adaptation. In conclusion, our study provides valuable information to further understand the response of rice roots to N-deficiency stress.


Assuntos
Glutamato-Amônia Ligase/metabolismo , Nitrogênio/deficiência , Oryza/genética , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/genética , Glutamato-Amônia Ligase/genética , Nitrogênio/metabolismo , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Proteômica/métodos , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo , Transcriptoma/genética
9.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068366

RESUMO

Magnaporthe oryzae (M. oryzae) is a typical cause of rice blast in agricultural production. Isobavachalcone (IBC), an active ingredient of Psoralea corylifolia L. extract, is an effective fungicide against rice blast. To determine the mechanism of IBC against M. oryzae, the effect of IBC on the metabolic pathway of M. oryzae was explored by transcriptome profiling. In M. oryzae, the expression of pyruvate dehydrogenase E1 (PDHE1), part of the tricarboxylic acid (TCA cycle), was significantly decreased in response to treatment with IBC, which was verified by qPCR and testing of enzyme activity. To further elucidate the interactions between IBC and PDHE1, the 3D structure model of the PDHE1 from M. oryzae was established based on homology modeling. The model was utilized to analyze the molecular interactions through molecular docking and molecular dynamics simulation, revealing that IBC has π-π stacking interactions with residue TYR139 and undergoes hydrogen bonding with residue ASP217 of PDHE1. Additionally, the nonpolar residues PHE111, MET174, ILE 187, VAL188, and MET250 form strong hydrophobic interactions with IBC. The above results reveal that PDHE1 is a potential target for antifungal agents, which will be of great significance for guiding the design of new fungicides. This research clarified the mechanism of IBC against M. oryzae at the molecular level, which will underpin further studies of the inhibitory mechanism of flavonoids and the discovery of new targets. It also provides theoretical guidance for the field application of IBC.


Assuntos
Chalconas/farmacologia , Proteínas Fúngicas/metabolismo , Magnaporthe/efeitos dos fármacos , Oryza/enzimologia , Doenças das Plantas/imunologia , Piruvato Desidrogenase (Lipoamida)/antagonistas & inibidores , Transcriptoma/efeitos dos fármacos , Proteínas Fúngicas/genética , Fungicidas Industriais/farmacologia , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Magnaporthe/fisiologia , Simulação de Acoplamento Molecular , Oryza/efeitos dos fármacos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Conformação Proteica , Piruvato Desidrogenase (Lipoamida)/genética , Piruvato Desidrogenase (Lipoamida)/metabolismo
10.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070465

RESUMO

Environmental or abiotic stresses are a common threat that remains a constant and common challenge to all plants. These threats whether singular or in combination can have devastating effects on plants. As a semiaquatic plant, rice succumbs to the same threats. Here we systematically look into the involvement of salicylic acid (SA) in the regulation of abiotic stress in rice. Studies have shown that the level of endogenous salicylic acid (SA) is high in rice compared to any other plant species. The reason behind this elevated level and the contribution of this molecule towards abiotic stress management and other underlying mechanisms remains poorly understood in rice. In this review we will address various abiotic stresses that affect the biochemistry and physiology of rice and the role played by SA in its regulation. Further, this review will elucidate the potential mechanisms that control SA-mediated stress tolerance in rice, leading to future prospects and direction for investigation.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/metabolismo , Ácido Salicílico/metabolismo , Estresse Fisiológico/fisiologia , Resposta ao Choque Frio/fisiologia , Secas , Regulação da Expressão Gênica de Plantas/genética , Resposta ao Choque Térmico/fisiologia , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Metais/metabolismo , Metais/toxicidade , Oryza/enzimologia , Reguladores de Crescimento de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/fisiologia
11.
BMC Plant Biol ; 21(1): 287, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34167489

RESUMO

BACKGROUND: Phosphoenolpyruvate carboxylase (PEPC) plays an important role in the primary metabolism of higher plants. Several studies have revealed the critical importance of PEPC in the interaction of carbon and nitrogen metabolism. However, the function mechanism of PEPC in nitrogen metabolism is unclear and needs further investigation. RESULTS: This study indicates that transgenic rice expressing the sugarcane C4-PEPC gene displayed shorter primary roots and fewer crown roots at the seedling stage. However, total nitrogen content was significantly higher in transgenic rice than in wild type (WT) plants. Proteomic analysis revealed that there were more differentially expressed proteins (DEPs) responding to nitrogen changes in transgenic rice. In particular, the most enriched pathway "glutathione (GSH) metabolism", which mainly contains GSH S-transferase (GST), was identified in transgenic rice. The expression of endogenous PEPC, GST and several genes involved in the TCA cycle, glycolysis and nitrogen assimilation changed in transgenic rice. Correspondingly, the activity of enzymes including GST, citrate synthase, 6-phosphofructokinase, pyruvate kinase and ferredoxin-dependent glutamate synthase significantly changed. In addition, the levels of organic acids in the TCA cycle and carbohydrates including sucrose, starch and soluble sugar altered in transgenic rice under different nitrogen source concentrations. GSH that the substrate of GST and its components including glutamic acid, cysteine and glycine accumulated in transgenic rice. Moreover, the levels of phytohormones including indoleacetic acid (IAA), zeatin (ZT) and isopentenyladenosine (2ip) were lower in the roots of transgenic rice under total nutrients. Taken together, the phenotype, physiological and biochemical characteristics of transgenic rice expressing C4-PEPC were different from WT under different nitrogen levels. CONCLUSIONS: Our results revealed the possibility that PEPC affects nitrogen metabolism through regulating GST, which provide a new direction and concepts for the further study of the PEPC functional mechanism in nitrogen metabolism.


Assuntos
Glutationa Transferase/metabolismo , Nitrogênio/metabolismo , Oryza/enzimologia , Fosfoenolpiruvato Carboxilase/metabolismo , Saccharum/enzimologia , Carbono/metabolismo , Oryza/genética , Oryza/metabolismo , Fosfoenolpiruvato Carboxilase/genética , Plantas Geneticamente Modificadas , Proteômica , Saccharum/genética , Transcriptoma
12.
Plant Mol Biol ; 106(4-5): 463-477, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34100185

RESUMO

KEY MESSAGE: OsPUB41 plays a negative role in drought stress response through the mediation of OsUBC25 and interacts with OsCLC6, suggesting a putative substrate. The notable expansion of Plant U-Box E3 ligases (PUB), compared with those in mammals, implies that PUB proteins have evolved to perform plant-specific functions. OsPUB41, a potential ortholog of CMPG1, was recently reported to regulate the cell wall degrading enzyme (CWDE)-induced innate immune response in rice. Here, we characterized the OsPUB41 gene, which encodes a dual-localized cytosolic and nuclear U-box E3 ligase in rice. OsPUB41 expression was specifically induced by dehydration among various abiotic stresses and abscisic acid (ABA) treatments. Furthermore, we revealed that the core U-box motif of OsPUB41 possesses the E3 ligase activity that can be activated by OsUBC25 in rice. The Ubi:RNAi-OsPUB41 knock-down and ospub41 suppression mutant plants exhibited enhanced tolerance to drought stress compared with the wild-type rice plants in terms of transpirational water loss, long-term dehydration response, and chlorophyll content. Moreover, the knock-down or suppression of the OsPUB41 gene did not cause adverse effect on rice yield-related traits. Yeast two-hybrid and an in vitro pull-down analyses revealed that OsCLC6, a chloride channel, is a putative substrate of OsPUB41. Overall, these results suggest that OsPUB41 acts as a negative regulator of dehydration conditions and interacts with OsCLC6, implying that it is a substrate of OsPUB41.


Assuntos
Oryza/enzimologia , Estresse Fisiológico , Ubiquitina-Proteína Ligases/genética , Ácido Abscísico/farmacologia , Núcleo Celular/metabolismo , Canais de Cloreto/metabolismo , Citosol/metabolismo , Secas , Técnicas de Silenciamento de Genes , Mutação , Oryza/efeitos dos fármacos , Oryza/genética , Plantas Geneticamente Modificadas , Ubiquitina-Proteína Ligases/metabolismo
13.
Plant Mol Biol ; 106(4-5): 419-432, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34129189

RESUMO

KEY MESSAGE: Coordinated regulation of amylose and amylopectin synthesis via manipulation of SSII-2, SSII-3 and Wx expression in endosperm can improve rice eating and cooking quality. With increasing rice consumption worldwide, many researchers are working to increase the yield and improve grain quality, especially eating and cooking quality (ECQ). The rice ECQ is mainly controlled by the expression of starch synthesis-related genes (SSRGs) in endosperm. Although the Wx and SSII-3/SSIIa/ALK genes, two major SSRGs, have been manipulated to improve rice ECQ via various breeding approaches, new methods to further improve ECQ are desired. In our previous study, we enhanced rice ECQ by knocking down SSII-2 expression in the japonica Nipponbare cultivar (carrying the Wxb allele) via RNA interference. Herein, the SSII-2 RNAi was introduced into two Nipponbare-derived near-isogenic lines (NILs), Nip(Wxa) and Nip(wx), carrying Wxa and wx alleles respond for high and no amylose levels, respectively. Analysis of physicochemical properties revealed that the improved grain quality of SSII-2 RNAi transgenic lines was achieved by coordinated downregulating the expression of SSII-2, SSII-3 and Wx. To further confirm this conclusion, we generated ssii-2, ssii-3 and ssii-2ssii-3 mutants via CRISPR/Cas9 technique. The amylopectin structure of the resulting ssii-2sii-3 mutants was similar to that in SSII-2 RNAi transgenic lines, and the absence of SSII-2 decreased the amylose content, gelatinisation temperature and rapid visco-analyser profile, indicating essential roles for SSII-2 in the regulation of amylopectin biosynthesis and amylose content in rice endosperm. The effect of SSII-2 was seen only when the activity of SSII-3 was very low or lacking. Our study provides novel approaches and valuable germplasm resources for improving ECQ via plant breeding.


Assuntos
Grão Comestível/genética , Endosperma/genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Amido/biossíntese , Culinária , Grão Comestível/enzimologia , Grão Comestível/fisiologia , Qualidade dos Alimentos , Oryza/enzimologia , Oryza/fisiologia , Proteínas de Plantas/genética , Interferência de RNA , Amido/genética , Sintase do Amido/genética
14.
Plant Cell Rep ; 40(9): 1603-1615, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34041586

RESUMO

Plants have developed sophisticated and complex epigenetic regulation-based mechanisms to maintain stable growth and development under diverse environmental conditions. Histone deacetylases (HDACs) are important epigenetic regulators in eukaryotes that are involved in the deacetylation of lysine residues of histone H3 and H4 proteins. Plants have developed a unique HDAC family, HD2, in addition to the RPD3 and Sir2 families, which are also present in other eukaryotes. HD2s are well conserved plant-specific HDACs, which were first identified as nucleolar phosphoproteins in maize. The HD2 family plays important roles not only in fundamental developmental processes, including seed germination, root and leaf development, floral transition, and seed development but also in regulating plant responses to biotic and abiotic stresses. Some of the HD2 members coordinate with each other to function. The HD2 family proteins also show functional association with RPD3-type HDACs and other transcription factors as a part of repression complexes in gene regulatory networks involved in environmental stress responses. This review aims to analyse and summarise recent research progress in the HD2 family, and to describe their role in plant growth and development and in response to different environmental stresses.


Assuntos
Histona Desacetilases/metabolismo , Fenômenos Fisiológicos Vegetais , Proteínas de Plantas/metabolismo , Estresse Fisiológico/fisiologia , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/fisiologia , Oryza/enzimologia , Oryza/fisiologia , Fosfoproteínas/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/genética , Solanum tuberosum/enzimologia , Solanum tuberosum/fisiologia
15.
Plant Cell Rep ; 40(7): 1215-1228, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34028583

RESUMO

KEY MESSAGE: Among the 113 lipases present in rice genome, bran and endosperm-specific lipases were identified and lipase activity for one of the selected lipase gene is demonstrated in yeast. Rice bran is nutritionally superior than endosperm as it has major reservoirs of various minerals, vitamins, essential mineral oils and other bioactive compounds, however it is often under-utilized as a food product due to bran instability after milling. Various hydrolytic enzymes, such as lipases, present in bran causes degradation of the lipids present and are responsible for the bran instability. Here, in this study, we have systematically analyzed the 113 lipase genes present in rice genome, and identified 21 seed-specific lipases. By analyzing the expression of these genes in different seed tissues during seed development, we have identified three bran-specific and three endosperm-specific lipases, and one lipase which expresses in both bran and endosperm tissues. Further analysis of these genes during seed maturation and seed germination revealed that their expression increases during seed maturation and decreases during seed germination. Finally, we have shown the lipase activity for one of the selected genes, LOC_Os05g30900, in heterologous system yeast. The bran-specific lipases identified in this study would be very valuable for engineering designer rice varieties having increased bran stability in post-milling.


Assuntos
Lipase/genética , Lipase/metabolismo , Oryza/enzimologia , Simulação por Computador , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Germinação , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Leveduras/genética , Leveduras/metabolismo
16.
Nat Genet ; 53(6): 906-915, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33927398

RESUMO

Phosphate (Pi) is essential to plant growth and crop yield. However, it remains unknown how Pi homeostasis is maintained during cereal grain filling. Here, we identified a rice grain-filling-controlling PHO1-type Pi transporter, OsPHO1;2, through map-based cloning. Pi efflux activity and its localization to the plasma membrane of seed tissues implicated a specific role for OsPHO1;2 in Pi reallocation during grain filling. Indeed, Pi over-accumulated in developing seeds of the Ospho1;2 mutant, which inhibited the activity of ADP-glucose pyrophosphorylase (AGPase), important for starch synthesis, and the grain-filling defect was alleviated by overexpression of AGPase in Ospho1;2-mutant plants. A conserved function was recognized for the maize transporter ZmPHO1;2. Importantly, ectopic overexpression of OsPHO1;2 enhanced grain yield, especially under low-Pi conditions. Collectively, we discovered a mechanism underlying Pi transport, grain filling and P-use efficiency, providing an efficient strategy for improving grain yield with minimal P-fertilizer input in cereals.


Assuntos
Membrana Celular/metabolismo , Grão Comestível/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Fosfatos/metabolismo , Animais , Membrana Celular/ultraestrutura , Mapeamento Cromossômico , Grão Comestível/ultraestrutura , Regulação da Expressão Gênica de Plantas , Células HEK293 , Humanos , Mutação/genética , Oryza/enzimologia , Oryza/genética , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/genética , Sementes/ultraestrutura , Amido/biossíntese , Xenopus , Zea mays/genética
17.
Biosci Biotechnol Biochem ; 85(6): 1476-1484, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-33720315

RESUMO

Formation of taste-active pyroglutamyl (pGlu) peptide ethyl esters in sake was investigated: 2 enzymes (A and B) responsible for the esterification were purified from a rice koji extract. MADLI-TOF/TOF analysis after deglycosylation identified enzyme (A) as peptidase S28 (GenBank accession number OOO13707.1) and enzyme (B) as serine-type carboxypeptidase (accession number AO090010000534). Both enzymes hydrolyzed pGlu peptides and formed ethyl esters under sake mash conditions: acidic pH (3-4) and in ethanol (5%-20% v/v) aqueous solutions. Enzyme (A) formed pGlu penta-peptide ethyl esters from pGlu undeca-peptides by a prolyl endo-type reaction. Enzyme (B) formed (pGlu) deca-peptide and its ethyl esters from pGlu undeca-peptides in an exo-type reaction. We are the first to report the enzymatic ethyl esterification reaction in the formation of pGlu peptides by rice koji peptidases.


Assuntos
Ésteres/química , Oryza/enzimologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Peptídeo Hidrolases/metabolismo , Paladar , Bebidas Alcoólicas/análise , Esterificação , Hidrólise
18.
Angew Chem Int Ed Engl ; 60(21): 12020-12026, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33682300

RESUMO

Serotonin N-acetyltransferase (SNAT) is the key rate-limiting enzyme in melatonin biosynthesis. It mediates melatonin biosynthesis in plants by using serotonin and 5-methoxytryptamine (5-MT), but little is known of its underlying mechanisms. Herein, we present a detailed reaction mechanism of a SNAT from Oryza sativa through combined structural and molecular dynamics (MD) analysis. We report the crystal structures of plant SNAT in the apo and binary/ternary complex forms with acetyl-CoA (AcCoA), serotonin, and 5-MT. OsSNAT exhibits a unique enzymatically active dimeric fold not found in the known structures of arylalkylamine N-acetyltransferase (AANAT) family. The key residues W188, D189, D226, N220, and Y233 located around the active pocket are important in catalysis, confirmed by site-directed mutagenesis. Combined with MD simulations, we hypothesize a novel plausible catalytic mechanism in which D226 and Y233 function as catalytic base and acid during the acetyl-transfer reaction.


Assuntos
Arilalquilamina N-Acetiltransferase/química , Proteínas de Plantas/química , 5-Metoxitriptamina/química , 5-Metoxitriptamina/metabolismo , Acetilcoenzima A/química , Acetilcoenzima A/metabolismo , Arilalquilamina N-Acetiltransferase/genética , Arilalquilamina N-Acetiltransferase/metabolismo , Biocatálise , Domínio Catalítico , Cristalografia por Raios X , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Mutação , Oryza/enzimologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ligação Proteica , Serotonina/química , Serotonina/metabolismo
19.
Biochem Biophys Res Commun ; 548: 189-195, 2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33647795

RESUMO

Abscisic acid (ABA) regulates many aspects of plant growth and development and the responses to abiotic stresses. Arabidopsis aldehyde oxidase 3 (AAO3) catalyzes the final step of ABA biosynthesis. We cloned and functionally characterized a novel aldehyde oxidase gene, OsAO3, the rice homolog of AAO3. OsAO3 was expressed in germinated seeds, roots, leaves, and floral organs, particularly in vascular tissues and guard cells, and its expression was significantly induced by exogenous ABA and mannitol. Mutation and overexpression of OsAO3 decreased and increased ABA levels, respectively, in seedling shoots and roots under both normal and drought stress conditions. The osao3 mutant exhibited earlier seed germination, increased seedling growth, and decreased drought tolerance compared to the wild-type, OsAO3-overexpressing lines exhibited the opposite phenotype. Mutation and overexpression of OsAO3 increased and decreased grain yield, respectively, by affecting panicle number per plant, spikelet number per panicle, and spikelet fertility. Thus, OsAO3 may participate in ABA biosynthesis, and is essential for regulation of seed germination, seedling growth, grain yield, and drought tolerance in rice.


Assuntos
Ácido Abscísico/metabolismo , Adaptação Fisiológica/genética , Secas , Genes de Plantas , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/genética , Oryza/genética , Oryza/fisiologia , Desenvolvimento Vegetal/genética , Sementes/genética , Estresse Fisiológico/genética , Água
20.
Plant Sci ; 306: 110876, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33775371

RESUMO

Acid rain, as a typical abiotic stress, damages plant growth and production. Calcium (Ca) mediates plant growth and links the signal transduction in plants for adapting to abiotic stresses. To understand the effect of Ca2+ on plant adaptable response to acid rain, we investigated changes in activities and gene expression of antioxidative enzymes and fatty acid composition of membrane lipid in rice seedlings treated with exogenous Ca2+ (5 mM) or/and simulated acid rain (SAR, pH 3.5 / 2.5). Exogenous Ca2+ enhanced activities of superoxide dismutase, catalase and peroxidase isozymes in rice leaves under SAR stress by promoting activation of existing isoforms and up-regulation of Cu/Zn-SOD1, Cu/Zn-SOD2, Cu/Zn-SOD3, CAT1, CAT2 and POD1. Compared to SAR treatment alone, exogenous Ca2+ alleviated SAR-induced oxidative damage to cell membrane by enhancing antioxidative capacity, as shown by the decrease in concentrations of H2O2, O2- and malondialdehyde in rice leaves. Meanwhile, Ca2+ alleviated SAR-induced decrease in unsaturation of membrane lipid for maintaining membrane fluidity. Finally, exogenous Ca2+ alleviated SAR-induced inhibition on relative growth rate of rice. Therefore, Ca2+ could play a role in regulating activities of antioxidative enzymes as well as maintaining unsaturation of membrane lipid for enhancing tolerance in rice seedlings to acid rain stress.


Assuntos
Chuva Ácida/efeitos adversos , Adaptação Fisiológica , Antioxidantes/metabolismo , Cálcio/metabolismo , Isoenzimas/metabolismo , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Estresse Fisiológico/fisiologia , Produtos Agrícolas/enzimologia , Produtos Agrícolas/crescimento & desenvolvimento
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