RESUMEN

In flowering plants, the tapetum degeneration in post-meiotic anther occurs through developmental programmed cell death (dPCD), which is one of the most critical and sensitive steps for the proper development of male gametophytes and fertility. Yet the pathways of dPCD, its regulation, and its interaction with autophagy remain elusive. Here, we report that high-level expression of Arabidopsis autophagy-related gene BECLIN1 (BECN1 or AtATG6) in the tobacco tapetum prior to their dPCD resulted in developmental defects. BECN1 induces severe autophagy and multiple cytoplasm-to-vacuole pathways, which alters tapetal cell reactive oxygen species (ROS)-homeostasis that represses the tapetal dPCD. The transcriptome analysis reveals that BECN1- expression caused major changes in the pathway, resulting in altered cellular homeostasis in the tapetal cell. Moreover, BECN1-mediated autophagy reprograms the execution of tapetal PCD by altering the expression of the key developmental PCD marker genes: SCPL48, CEP1, DMP4, BFN1, MC9, EXI1, and Bcl-2 member BAG5, and BAG6. This study demonstrates that BECN1-mediated autophagy is inhibitory to the dPCD of the tapetum, but the severity of autophagy leads to autophagic death in the later stages. The delayed and altered mode of tapetal degeneration resulted in male sterility.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Beclina-1/genética , Beclina-1/metabolismo , Apoptosis/genética , Homeostasis , Autofagia/genética , Regulación de la Expresión Génica de las Plantas , Flores/metabolismo , Proteínas Nucleares/genética , Chaperonas Moleculares/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo

RESUMEN

Climate change inflicts several stresses on plants, of which dehydration stress severely affects growth and productivity. C4 plants possess better adaptability to dehydration stress; however, the role of epigenetic modifications underlying this trait is unclear. In particular, the molecular links between histone modifiers and their regulation remain elusive. In this study, genome-wide H3K9 acetylation (H3K9ac) enrichment using ChIP-sequencing was performed in two foxtail millet cultivars with contrasting dehydration tolerances (IC403579, cv. IC4-tolerant, and IC480117, cv. IC41-sensitive). It revealed that a histone deacetylase, SiHDA9, was significantly up-regulated in the sensitive cultivar. Further characterization indicated that SiHDA9 interacts with SiHAT3.1 and SiHDA19 to form a repressor complex. SiHDA9 might be recruited through the SiHAT3.1 recognition sequence onto the upstream of dehydration-responsive genes to decrease H3K9 acetylation levels. The silencing of SiHDA9 resulted in the up-regulation of crucial genes, namely, SiRAB18, SiRAP2.4, SiP5CS2, SiRD22, SiPIP1;4, and SiLHCB2.3, which imparted dehydration tolerance in the sensitive cultivar (IC41). Overall, the study provides mechanistic insights into SiHDA9-mediated regulation of dehydration stress response in foxtail millet.

Asunto(s)

Deshidratación , Setaria (Planta) , Setaria (Planta)/genética , Regulación hacia Arriba , Fenotipo , Histona Desacetilasas/genética , Regulación de la Expresión Génica de las Plantas , Estrés Fisiológico/genética , Proteínas de Plantas/genética

RESUMEN

Upland cotton (Gossypium hirsutum L.) is a major fiber crop that is cultivated worldwide and has significant economic importance. India harbors the largest area for cotton cultivation, but its fiber yield is still compromised and ranks 22nd in terms of productivity. Genetic improvement of cotton fiber yield traits is one of the major goals of cotton breeding, but the understanding of the genetic architecture underlying cotton fiber yield traits remains limited and unclear. To better decipher the genetic variation associated with fiber yield traits, we conducted a comprehensive genome-wide association mapping study using 117 Indian cotton germplasm for six yield-related traits. To accomplish this, we generated 2,41,086 high-quality single nucleotide polymorphism (SNP) markers using genotyping-by-sequencing (GBS) methods. Population structure, PCA, kinship, and phylogenetic analyses divided the germplasm into two sub-populations, showing weak relatedness among the germplasms. Through association analysis, 205 SNPs and 134 QTLs were identified to be significantly associated with the six fiber yield traits. In total, 39 novel QTLs were identified in the current study, whereas 95 QTLs overlapped with existing public domain data in a comparative analysis. Eight QTLs, qGhBN_SCY_D6-1, qGhBN_SCY_D6-2, qGhBN_SCY_D6-3, qGhSI_LI_A5, qGhLI_SI_A13, qGhLI_SI_D9, qGhBW_SCY_A10, and qGhLP_BN_A8 were identified. Gene annotation of these fiber yield QTLs revealed 2,509 unique genes. These genes were predominantly enriched for different biological processes, such as plant cell wall synthesis, nutrient metabolism, and vegetative growth development in the gene ontology (GO) enrichment study. Furthermore, gene expression analysis using RNAseq data from 12 diverse cotton tissues identified 40 candidate genes (23 stable and 17 novel genes) to be transcriptionally active in different stages of fiber, ovule, and seed development. These findings have revealed a rich tapestry of genetic elements, including SNPs, QTLs, and candidate genes, and may have a high potential for improving fiber yield in future breeding programs for Indian cotton.

RESUMEN

MAIN CONCLUSION: Transcript isoform dynamics, spatiotemporal expression, and mutational analysis uncover that Arabidopsis RabC1 GTPase is required for root length, flowering time, seed size, and seed mucilage. Rab GTPases are crucial regulators for moving different molecules to their specific compartments according to the needs of the cell. In this work, we illustrate the role of RabC1 GTPase in Arabidopsis growth and seed development. We identify and analyze the expression pattern of three transcript isoforms of RabC1 in different development stages, along with their tissue-specific transcript abundance. The promoter activity of RabC1 using promoter-GUS fusion shows that it is widely expressed during the growth of Arabidopsis, particularly in seed tissues such as chalazal seed coat and chalazal endosperm. Lack of RabC1 function led to shorter roots, lesser biomass, delayed flowering, and sluggish plant development. The mutants had smaller seeds than the wildtype, less seed mass, and lower seed coat permeability. Developing seeds also revealed a smaller endosperm cavity and shorter integument cells. Additionally, we found that the knock-out mutant had downregulated expression of genes implicated in the transit of sugars and amino acids from maternal tissue to developing seed. The seeds of the loss-of-function mutant had reduced seed mucilage. All the observed mutant phenotypes were restored in the complemented lines confirming the function of RabC1 in seed development and plant growth.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Semillas , Endospermo/genética , Desarrollo de la Planta , Regulación de la Expresión Génica de las Plantas

RESUMEN

BACKGROUND: Tobacco's PR-1a gene is induced by pathogen attack or exogenous application of salicylic acid (SA). Nucleosome mapping and chromatin immunoprecipitation assay were used to delineate the histone modifications on the PR-1a promoter. However, the epigenetic modifications of the inducible promoter of the PR-1a gene are not fully understood yet. METHODS AND RESULTS: Southern approach was used to scan the promoter of PR-1a to identify presence of nucleosomes, ChIP assays were performed using anti-histones antibodies of repressive chromatin by di- methylated at H3K9 and H4K20 or active chromatin by acetylated H3K9/14 and H4K16 to find epigenetic malleability of nucleosome over core promoter in uninduced or induced state post SA treatment. Class I and II mammalian histone deacetylase (HDAC) inhibitor TSA treatment was used to enhance the expression of PR-1a by facilitating the histone acetylation post SA treatment. Here, we report correlated consequences of the epigenetic modifications correspond to disassembly of the nucleosome (spans from - 102 to + 55 bp, masks TATA and transcription initiation) and repressor complex from core promoter, eventually initiates the transcription of PR-1a gene post SA treatment. While active chromatin marks di and trimethylation of H3K4, acetylation of H3K9 and H4K16 are increased which are associated to the transcription initiation of PR-1a following SA treatment. However, in uninduced state constitutive expression of a negative regulator (SNI1) of AtPR1, suppresses AtPR1 expression by six-fold in Arabidopsis thaliana. Further, we report 50-to-1000-fold increased expression of AtPR1 in uninduced lsd1 mutant plants, up to threefold increased expression of AtPR1 in uninduced histone acetyl transferases (HATs) mutant plants, SNI1 dependent negative regulation of AtPR1, all together our results suggest that inactive state of PR-1a is indeed maintained by a repressive complex. CONCLUSION: The study aimed to reveal the mechanism of transcription initiation of tobacco PR-1a gene in presence or absence of SA. This is the first study that reports nucleosome and repressor complex over core promoter region maintains the inactivation of gene in uninduced state, and upon induction disassembling of both initiates the downstream gene activation process.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Animales , Nucleosomas/genética , Nucleosomas/metabolismo , Ácido Salicílico/farmacología , Ácido Salicílico/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Regiones Promotoras Genéticas/genética , Cromatina/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Epigénesis Genética , Acetilación , Mamíferos/metabolismo , Proteínas Nucleares/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo

RESUMEN

Advancement of the gene expression study provides comprehensive information on pivotal genes at different cotton fiber development stages. For the betterment of cotton fiber yield and their quality, genetic improvement is a major target point for the cotton community. Therefore, various studies were carried out to understand the transcriptional machinery of fiber leading to the detailed integrative as well as innovative study. Through data mining and statistical approaches, we identified and validated the transcriptional biomarkers for staged specific differentiation of fiber. With the unique mapping read matrix of ~ 200 cotton transcriptome data and sequential statistical analysis, we identified several important genes that have a deciding and specific role in fiber cell commitment, initiation and elongation, or secondary cell wall synthesis stage. Based on the importance score and validation analysis, IQ domain 26, Aquaporin, Gibberellin regulated protein, methionine gamma lyase, alpha/beta hydrolases, and HAD-like superfamily have shown the specific and determining role for fiber developmental stages. These genes are represented as transcriptional biomarkers that provide a base for molecular characterization for cotton fiber development which will ultimately determine the high yield.

Asunto(s)

Fibra de Algodón , Liasas , Biomarcadores , Minería de Datos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Giberelinas , Gossypium/genética , Hidrolasas , Metionina

RESUMEN

Cotton fiber development is still an intriguing question to understand fiber commitment and development. At different fiber developmental stages, many genes change their expression pattern and have a pivotal role in fiber quality and yield. Recently, numerous studies have been conducted for transcriptional regulation of fiber, and raw data were deposited to the public repository for comprehensive integrative analysis. Here, we remapped > 380 cotton RNAseq data with uniform mapping strategies that span ∼400 fold coverage to the genome. We identified stage-specific features related to fiber cell commitment, initiation, elongation, and Secondary Cell Wall (SCW) synthesis and their putative cis-regulatory elements for the specific regulation in fiber development. We also mined Exclusively Expressed Transcripts (EETs) that were positively selected during cotton fiber evolution and domestication. Furthermore, the expression of EETs was validated in 100 cotton genotypes through the nCounter assay and correlated with different fiber-related traits. Thus, our data mining study reveals several important features related to cotton fiber development and improvement, which were consolidated in the "CottonExpress-omics" database.

RESUMEN

Genome wide quantitative trait loci (QTL) mapping was conducted in Arabidopsis thaliana using F2 mapping population (Col-0 × Don-0) and SNPs markers. A total of five linkage groups were obtained with number of SNPs varying from 45 to 59 per linkage group. The composite interval mapping detected a total of 36 QTLs for 15 traits and the number of QTLs ranged from one (root length, root dry biomass, cauline leaf width, number of internodes and internode distance) to seven (for bolting days). The range of phenotypic variance explained (PVE) and logarithm of the odds ratio of these 36 QTLs was found be 0.19-38.17% and 3.0-6.26 respectively. Further, the epistatic interaction detected one main effect QTL and four epistatic QTLs. Five major QTLs viz. Qbd.nbri.4.3, Qfd.nbri.4.2, Qrdm.nbri.5.1, Qncl.nbri.2.2, Qtd.nbri.4.1 with PVE > 15.0% might be useful for fine mapping to identify genes associated with respective traits, and also for development of specialized population through marker assisted selection. The identification of additive and dominant effect QTLs and desirable alleles of each of above mentioned traits would also be important for future research.

RESUMEN

During plant-pathogen interaction, immune targets were regulated by protein-protein interaction events such as ligand-receptor/co-receptor, kinase-substrate, protein sequestration, activation or repression via post-translational modification and homo/oligo/hetro-dimerisation of proteins. A judicious use of molecular machinery requires coordinated protein interaction among defence components. Immune signalling in Arabidopsis can be broadly represented in successive or simultaneous steps; pathogen recognition at cell surface, Ca2+ and reactive oxygen species signalling, MAPK signalling, post-translational modification, transcriptional regulation and phyto-hormone signalling. Proteome wide interaction studies have shown the existence of interaction hubs associated with physiological function. So far, a number of protein interaction events regulating immune targets have been identified, but their understanding in an interactome view is lacking. We focussed specifically on the integration of protein interaction signalling in context to plant-pathogenesis and identified the key targets. The present review focuses towards a comprehensive view of the plant immune interactome including signal perception, progression, integration and physiological response during plant pathogen interaction.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Procesamiento Proteico-Postraduccional , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal

RESUMEN

Prickles are epidermal outgrowth found on the aerial surface of several terrestrial plants. Microscopic studies on prickles of S. viarum Dunal indicated a crucial role of glandular trichomes (GTs) in their development. A spontaneously obtained prickleless mutant showed normal epidermal GTs, but its downstream developmental process to prickle was perturbed. Thus, prickleless mutant offers an ideal opportunity to unveil molecular regulators working downstream to GTs in the prickle formation. Differential transcriptome analysis of epidermis of prickly and prickleless mutant revealed that expression of several defense regulators like ethylene, salicylic acid, PR-proteins, etc. were significantly down-regulated in prickleless mutant, provide an important link between defense and prickle development. It was also noteworthy that the expression of few essential development related TFs like MADS-box, R2R3-MYB, REM, DRL1, were also down-regulated in the stem, petioles, and leaves of prickleless mutant indicating their potential role in prickle development. Interestingly, the gene expression of terpenoid, steroid, flavonoid, glucosinolate, and lignin biosynthesis pathways were up-regulated in prickleless mutant. The biochemical and qRT-PCR analysis also confirmed metabolite elevation. These results indicated that the loss of prickle was compensated by elevated secondary metabolism in the prickleless mutant which played important role in the biotic and abiotic stress management.

Asunto(s)

Mutación , Proteínas de Plantas/genética , Solanum/genética , Estrés Fisiológico , Transcriptoma , Tricomas/crecimiento & desarrollo , Tricomas/inmunología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Redes y Vías Metabólicas , Polimorfismo de Nucleótido Simple , Solanum/crecimiento & desarrollo , Solanum/inmunología , Tricomas/genética

RESUMEN

Cotton fibers are single-celled trichomes that initiate from the epidermal cells of the ovules at or before anthesis. Here, we identified that the histone deacetylase (HDAC) activity is essential for proper cotton fiber initiation. We further identified 15 HDACs homoeologs in each of the A- and D-subgenomes of Gossypium hirsutum. Few of these HDAC homoeologs expressed preferentially during the early stages of fiber development [-1, 0 and 6 days post-anthesis (DPA)]. Among them, GhHDA5 expressed significantly at the time of fiber initiation (-1 and 0 DPA). The in vitro assay for HDAC activity indicated that GhHDA5 primarily deacetylates H3K9 acetylation marks. Moreover, the reduced expression of GhHDA5 also suppresses fiber initiation and lint yield in the RNA interference (RNAi) lines. The 0 DPA ovules of GhHDA5RNAi lines also showed alterations in reactive oxygen species homeostasis and elevated autophagic cell death in the developing fibers. The differentially expressed genes (DEGs) identified through RNA-seq of RNAi line (DEP12) and their pathway analysis showed that GhHDA5 modulates expression of many stress and development-related genes involved in fiber development. The reduced expression of GhHDA5 in the RNAi lines also resulted in H3K9 hyper-acetylation on the promoter region of few DEGs assessed by chromatin immunoprecipitation assay. The positively co-expressed genes with GhHDA5 showed cumulative higher expression during fiber initiation, and gene ontology annotation suggests their involvement in fiber development. Furthermore, the predicted protein interaction network in the positively co-expressed genes indicates HDA5 modulates fiber initiation-specific gene expression through a complex involving reported repressors.

Asunto(s)

Fibra de Algodón , Gossypium/metabolismo , Histona Desacetilasas/fisiología , Histonas/metabolismo , Proteínas de Plantas/fisiología , Diferenciación Celular , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Gossypium/crecimiento & desarrollo , Gossypium/fisiología , Histona Desacetilasas/metabolismo , Histonas/fisiología , Estrés Oxidativo , Proteínas de Plantas/metabolismo , Interferencia de ARN

RESUMEN

The CAMTA gene family is crucial in managing both biotic and abiotic stresses in plants. Our comprehensive analysis of this gene family in cotton resulted in the identification of 6, 7 and 9 CAMTAs in three sequenced cotton species, i.e., Gossypium arboreum, Gossypium raimondii, and Gossypium hirsutum, respectively. All cotton CAMTAs were localized in the nucleus and possessed calmodulin-binding domain (CaMBD) as identified computationally. Phylogenetically four significant groups of cotton CAMTAs were identified out of which, Group II CAMTAs experienced higher evolutionary pressure, leading to a faster evolution in diploid cotton. The expansion of cotton CAMTAs in the genome was mainly due to segmental duplication. Purifying selection played a significant role in the evolution of cotton CAMTAs. Expression profiles of GhCAMTAs revealed that GhCAMTA2A.2 and GhCAMTA7A express profoundly in different stages of cotton fiber development. Positive correlation between expression of these two CAMTAs and fiber strength confirmed their functional relevance in fiber development. The promoter region of co-expressing genes network of GhCAMTA2A.2 and GhCAMTA7A showed a higher frequency of occurrence of CAMTA binding motifs. Our present study thus contributes to broad probing into the structure and probable function of CAMTA genes in Gossypium species.

Asunto(s)

Evolución Molecular , Genómica , Gossypium/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Cromosomas de las Plantas/genética , Fibra de Algodón , Regulación de la Expresión Génica de las Plantas , Filogenia , Proteínas de Plantas/química , Factores de Transcripción/química

RESUMEN

Lack of regulated expression and tissue specificity are the major drawbacks of plant and virus-derived constitutive promoters. A precise tissue or site-specific expression, facilitate regulated expression of proteins at the targeted time and site. Publically available microarray data on whitefly and aphid infested Arabidopsis thaliana L. was used to identify whitefly and aphid-inducible genes. The qRT-PCR further validated the inducible behaviour of these genes under artificial infestation. Promoter sequences of genes were retrieved from the Arabidopsis Information Resources database with their corresponding 5'UTR and cloned from the A. thaliana genome. Promoter reporter transcriptional fusions were developed with the beta-glucuronidase (GUS) gusA gene in a binary expression vector to validate the inducible behaviour of these promoters in eight independent transgenic Nicotiana tabaccum lines. Histochemical analysis of the reporter gene in T2 transgenic tobacco lines confirmed promoter driven expression at the sites of aphid and whitefly infestation. The qRT-PCR and GUS expression analysis of transgenic lines revealed that abscisic acid largely influenced the expression of both aphid and whitefly inducible promoters. Further, whitefly-specific promoter respond to salicylic acid and jasmonic acid (JA), whereas aphid-specific promoters to JA and 1-aminocyclopropane carboxylic acid. The response of promoters to phytohormones correlated to the presence of corresponding conserved cis-regulatory elements.

Asunto(s)

Áfidos/fisiología , Arabidopsis/genética , Arabidopsis/parasitología , Regulación de la Expresión Génica de las Plantas , Hemípteros/fisiología , Regiones Promotoras Genéticas , Ácido Abscísico/farmacología , Animales , Ciclopentanos/farmacología , Genes de Plantas , Glucuronidasa/metabolismo , Oxilipinas/farmacología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/parasitología , Plantas Modificadas Genéticamente , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Ácido Salicílico/farmacología , Nicotiana/genética

RESUMEN

Cotton fiber is a specialized unicellular structure useful for the study of cellular differentiation and development. Heat shock proteins (HSPs) have been shown to be involved in various developmental processes. Microarray data analysis of five Gossypium hirsutum genotypes revealed high transcript levels of GhHSP90 and GhHSP70 genes at different stages of fiber development, indicating their importance in the process. Further, we identified 26 and 55 members of HSP90 and HSP70 gene families in G. hirsutum. The treatment of specific inhibitors novobiocin (Nov; HSP90) and pifithrin/2-phenylethynesulfonamide (Pif; HSP70) in in-vitro cultured ovules resulted in a fewer number of fiber initials and retardation in fiber elongation. The molecular chaperone assay using bacterially expressed recombinant GhHSP90-7 and GhHSP70-8 proteins further confirmed the specificity of inhibitors. HSP inhibition disturbs the H2O2 balance that leads to the generation of oxidative stress, which consequently results in autophagy in the epidermal layer of the cotton ovule. Transmission electron microscopy (TEM) of inhibitor-treated ovule also corroborates autophagosome formation along with disrupted mitochondrial cristae. The perturbations in transcript profile of HSP inhibited ovules show differential regulation of different stress and fiber development-related genes and pathways. Altogether, our results indicate that HSP90 and HSP70 families play a crucial role in cotton fiber differentiation and development by maintaining cellular homeostasis.

Asunto(s)

Gossypium/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Benzotiazoles/farmacología , Fibra de Algodón , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Gossypium/efectos de los fármacos , Novobiocina/farmacología , Estrés Oxidativo/efectos de los fármacos , Proteínas de Plantas/metabolismo , Sulfonamidas/farmacología , Tolueno/análogos & derivados , Tolueno/farmacología

RESUMEN

Microbulbifer mangrovi strain DD-13T is a novel-type species isolated from the mangroves of Goa, India. The draft genome sequence of strain DD-13 comprised 4,528,106 bp with G+C content of 57.15%. Out of 3479 open reading frames, functions for 3488 protein coding sequences were predicted on the basis of similarity with the cluster of orthologous groups. In addition to protein coding sequences, 34 tRNA genes and 3 rRNA genes were detected. Analysis of nucleotide sequence of predicted gene using a Carbohydrate-Active Enzymes (CAZymes) Analysis Toolkit indicates that strain DD-13 encodes a large set of CAZymes including 255 glycoside hydrolases, 76 carbohydrate esterases, 17 polysaccharide lyases, and 113 carbohydrate-binding modules (CBMs). Many genes from strain DD-13 were annotated as carbohydrases specific for degradation of agar, alginate, carrageenan, chitin, xylan, pullulan, cellulose, starch, ß-glucan, pectin, etc. Some of polysaccharide-degrading genes were highly modular and were appended at least with one CBM indicating the versatility of strain DD-13 to degrade complex polysaccharides. The cell growth of strain DD-13 was validated using pure polysaccharides such as agarose or alginate as carbon source as well as by using red and brown seaweed powder as substrate. The homologous carbohydrase produced by strain DD-13 during growth degraded the polysaccharide, ensuring the production of metabolizable reducing sugars. Additionally, several other polysaccharides such as carrageenan, xylan, pullulan, pectin, starch, and carboxymethyl cellulose were also corroborated as growth substrate for strain DD-13 and were associated with concomitant production of homologous carbohydrase.

Asunto(s)

Proteínas Bacterianas/genética , Gammaproteobacteria/genética , Regulación Bacteriana de la Expresión Génica , Genoma Bacteriano , Glicósido Hidrolasas/genética , Polisacáridos/metabolismo , Proteínas Bacterianas/clasificación , Proteínas Bacterianas/metabolismo , Composición de Base , Biodegradación Ambiental , Medios de Cultivo , Gammaproteobacteria/enzimología , Ontología de Genes , Tamaño del Genoma , Glicósido Hidrolasas/clasificación , Glicósido Hidrolasas/metabolismo , Hidrólisis , Anotación de Secuencia Molecular , Sistemas de Lectura Abierta , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Algas Marinas/química

RESUMEN

Secondary cell wall (SCW) biosynthesis is an important stage of the cotton fibre development, and its transcriptional regulation is poorly understood. We selected the Gossypium hirsutum GDSL (GhGDSL) lipase/hydrolase gene (CotAD_74480), which is expressed during SCW biosynthesis (19 through to 25 days postanthesis; DPA), for study. T1 -transgenic cotton lines expressing the ß-glucuronidase (gus) reporter under the control of a 1026-bp promoter fragment of GhGDSL (PGhGDSL ) showed 19 DPA stage-specific increase in GUS expression. 5' deletion indicated that the 194-bp fragment between -788 and -594 relative to the transcription start site was essential for this stage-specific expression. Site-directed mutagenesis of eight transcription factor binding sites within PGhGDSL demonstrated that the MYB1AT motif (AAACCA) at -603/-598 was critical for the 19 DPA-specific reporter gene expressions. Yeast one-hybrid (Y1H) analysis identified nine proteins, including GhMYB1 (CotAD_64719) that bound to the PGhGDSL promoter. Further, Y1H experiments using the 5' promoter deletions and individually mutated promoter motifs indicated that GhMYB1 interacted with PGhGDSL at MYB1AT sequence. GhMYB1 was expressed specifically in fibre from 19 DPA, overlapping with the sharp rise in GhGDSL expression, indicating that it could regulate GhGDSL during fibre development. Analysis of genes co-expressed with GhMYB1 showed that it potentially regulates a number of other 19-25 DPA-specific genes in networks including those functioning in the cell wall and precursor synthesis, but not the major polysaccharide and protein components of the fibre SCW. GhGDSL and its promoter are therefore potential tools for the improvement of cotton fibre quality traits.

Asunto(s)

Fibra de Algodón , Regulación de la Expresión Génica de las Plantas/genética , Gossypium/genética , Proteínas de Plantas/metabolismo , Regiones Promotoras Genéticas/genética , Sitios de Unión , Pared Celular/metabolismo , Glucuronidasa , Gossypium/enzimología , Gossypium/crecimiento & desarrollo , Hidrolasas/genética , Hidrolasas/metabolismo , Lipasa/genética , Lipasa/metabolismo , Mutagénesis Sitio-Dirigida , Fenotipo , Proteínas de Plantas/genética , Unión Proteica , Factores de Transcripción/genética , Factores de Transcripción/metabolismo

RESUMEN

Microarrays offer an opportunity to explore the functional sequence polymorphism among different cultivars of many crop plants. The Affymetrix microarray expression data of five genotypes of Gossypium hirsutum L. at six different fibre developmental stages was used to identify single feature polymorphisms (SFPs). The background corrected and quantile-normalized log2 intensity values of all probes of triplicate data of each cotton variety were subjected to SFPs call by using SAM procedure in R language software. We detected a total of 37,473 SFPs among six pair genotype combinations of two superior (JKC777 and JKC725) and three inferior (JKC703, JKC737 and JKC783) using the expression data. The 224 SFPs covering 51 genes were randomly selected from the dataset of all six fibre developmental stages of JKC777 and JKC703 for validation by sequencing on a capillary sequencer. Of these 224 SFPs, 132 were found to be polymorphic and 92 monomorphic which indicate that the SFP prediction from the expression data in the present study confirmed a ~58.92% of true SFPs. We further identified that most of the SFPs are associated with genes involved in fatty acid, flavonoid, auxin biosynthesis etc. indicating that these pathways significantly involved in fibre development.

Asunto(s)

Gossypium/genética , Polimorfismo Genético/genética , Fibra de Algodón/métodos , Perfilación de la Expresión Génica/métodos , Genotipo , Análisis por Micromatrices/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos

RESUMEN

The recruitment of RNA polymerase II on a promoter is assisted by the assembly of basal transcriptional machinery in eukaryotes. The Spt-Ada-Gcn5-Acetyltransferase (SAGA) complex plays an important role in transcription regulation in eukaryotes. However, even in the advent of genome sequencing of various plants, SAGA complex has been poorly defined for their components and roles in plant development and physiological functions. Computational analysis of Arabidopsis thaliana and Oryza sativa genomes for SAGA complex resulted in the identification of 17 to 18 potential candidates for SAGA subunits. We have further classified the SAGA complex based on the conserved domains. Phylogenetic analysis revealed that the SAGA complex proteins are evolutionary conserved between plants, yeast and mammals. Functional annotation showed that they participate not only in chromatin remodeling and gene regulation, but also in different biological processes, which could be indirect and possibly mediated via the regulation of gene expression. The in silico expression analysis of the SAGA components in Arabidopsis and O. sativa clearly indicates that its components have a distinct expression profile at different developmental stages. The co-expression analysis of the SAGA components suggests that many of these subunits co-express at different developmental stages, during hormonal interaction and in response to stress conditions. Quantitative real-time PCR analysis of SAGA component genes further confirmed their expression in different plant tissues and stresses. The expression of representative salt, heat and light inducible genes were affected in mutant lines of SAGA subunits in Arabidopsis. Altogether, the present study reveals expedient evidences of involvement of the SAGA complex in plant gene regulation and stress responses.

Asunto(s)

Complejos Multiproteicos/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Transactivadores/metabolismo , Evolución Biológica , Cromosomas de las Plantas , Análisis por Conglomerados , Secuencia Conservada , Bases de Datos de Ácidos Nucleicos , Evolución Molecular , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes , Genoma de Planta , Estudio de Asociación del Genoma Completo , Anotación de Secuencia Molecular , Filogenia , Plantas/clasificación , Plantas/genética , Dominios y Motivos de Interacción de Proteínas , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Estrés Fisiológico/genética

RESUMEN

Hybrid seeds are used for stimulated crop production, as they harness heterosis. The achievement of complete male-sterility in the female-parent and the restored-fertility in F1-hybrids are the major bottlenecks in the commercial hybrid seed production. Here, we report a male sterility-fertility restoration system by engineering the in most nutritive anther wall layer tapetum of female and male parents. In the female parent, high-level, and stringent expression of Arabidopsis autophagy-related gene BECLIN1 was achieved in the tapetum, which altered the tapetal degeneration program, leading to male sterility. This works on our previously demonstrated expression cassette based on functional complementation of TATA-box mutant (TGTA) promoter and TATA-binding protein mutant3 (TBPm3), with modification by conjugating Long Hypocotyle in Far-Red1 fragment (HFR1(NT131)) with TBPm3 (HFR1(NT131)-TBPm3) to exercise regulatory control over it. In the male parent, tapetum-specific Constitutive photo-morphogenesis1 (COP1) was expressed. The F1 obtained by crossing these engineered parents showed decreased BECLIN1 expression, which was further completely abolished when COP1-mutant (COP1(L105A)) was used as a male parent, leading to normal tapetal development and restored fertility. The system works on COP1-HFR1 interaction and COP1-mediated degradation of TBPm3 pool (HFR1(NT131)-TBPm3). The system can be deployed for hybrid seed production in agricultural crops.

Asunto(s)

Arabidopsis/genética , Quimera/genética , Flores/genética , Regulación de la Expresión Génica de las Plantas , Fitomejoramiento/métodos , Infertilidad Vegetal/genética , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autofagia/genética , Beclina-1 , Quimera/crecimiento & desarrollo , Quimera/metabolismo , Cruzamientos Genéticos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Flores/crecimiento & desarrollo , Flores/metabolismo , Prueba de Complementación Genética , Patrón de Herencia , Mutación , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Semillas/genética , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Proteína de Unión a TATA-Box/genética , Proteína de Unión a TATA-Box/metabolismo , Ubiquitina-Proteína Ligasas