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1.
Trends Plant Sci ; 29(4): 403-405, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38155045

RESUMO

Recently, it has been proposed that the respiratory metabolism of endophytes leads to an increased internal concentration of CO2, which contributes to higher photosynthesis. We argue that endophytes contribute to improved photosynthetic efficiency and net carbon gains by minimizing photosynthetic limitations.


Assuntos
Dióxido de Carbono , Endófitos , Dióxido de Carbono/metabolismo , Fotossíntese , Carbono
2.
Res Microbiol ; 174(4): 104045, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36842715

RESUMO

Salmonella, a foodborne human pathogen, can colonize the members of the kingdom Plantae. However, the basis of the persistence of Salmonella in plants is largely unknown. Plants encounter various biotic and abiotic stress agents in soil. We conjectured that methylglyoxal (MG), one of the common metabolites that accumulate in plants during both biotic and abiotic stress, plays a role in regulating the plant-Salmonella interaction. The interaction of Salmonella Typhimurium with plants under salinity stress was investigated. It was observed that wild-type Salmonella Typhimurium can efficiently colonize the root, but mutant bacteria lacking MG detoxifying enzyme, lactoyl-glutathione lyase (Lgl), showed lower colonization in roots exclusively under salinity stress. This colonization defect is due to the poor viability of the mutated bacterial strains under these conditions. This is the first report to prove the role of MG-detoxification genes in the colonization of stressed plants and highlights the possible involvement of metabolic genes in the evolution of the plant-associated life of Salmonella.


Assuntos
Lactoilglutationa Liase , Fenômenos Fisiológicos Vegetais , Salmonella typhimurium , Humanos , Bactérias/metabolismo , Glutationa/metabolismo , Interações entre Hospedeiro e Microrganismos , Lactoilglutationa Liase/genética , Lactoilglutationa Liase/metabolismo , Salinidade , Salmonella typhimurium/metabolismo , Estresse Salino , Estresse Fisiológico
3.
Plant Signal Behav ; 17(1): 2120300, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36373371

RESUMO

Drought challenges crop production worldwide. The issue is aggravated by frequent drought episodes and unpredictable rainfall patterns associated with global climate change. While the efforts to breed drought-resistant crop varieties are progressing, the need of the hour is immediate strategies to sustain the yields of existing ones. As per recent studies, stress adaptive traits can be activated using specific elicitors. Endophytes that inhabit host plants asymptomatically are natural elicitors/bio-stimulators capable of activating host gene expression, conferring several benefits to the hosts. This review discusses the scope of using trait-specific endophytes in activating drought adaptive traits in crop varieties.


Assuntos
Secas , Endófitos , Endófitos/fisiologia , Produtos Agrícolas/genética , Fenótipo , Mudança Climática
4.
Int J Mol Sci ; 23(16)2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-36012460

RESUMO

In the wake of changing climatic conditions, plants are frequently exposed to a wide range of biotic and abiotic stresses at various stages of their development, all of which negatively affect their growth, development, and productivity. Drought is one of the most devastating abiotic stresses for most cultivated crops, particularly in arid and semiarid environments. Conventional breeding and biotechnological approaches are used to generate drought-tolerant crop plants. However, these techniques are costly and time-consuming. Plant-colonizing microbes, notably, endophytic fungi, have received increasing attention in recent years since they can boost plant growth and yield and can strengthen plant responses to abiotic stress. In this review, we describe these microorganisms and their relationship with host plants, summarize the current knowledge on how they "reprogram" the plants to promote their growth, productivity, and drought tolerance, and explain why they are promising agents in modern agriculture.


Assuntos
Secas , Endófitos , Produtos Agrícolas/microbiologia , Endófitos/fisiologia , Melhoramento Vegetal , Estresse Fisiológico
5.
Plant Sci ; 320: 111262, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35643604

RESUMO

Under semi-irrigated ecosystem, rice is often exposed to a combination of drought and heat stress, especially at the reproductive stage, leading to substantial yield loss. Combined stress studies are very limited in rice partly due to the difficulty in creating heat stress on a larger scale. Here, 24 cultivars with specific stress adaptive traits were phenotyped for spikelet sterility under combined stress using the natural summer temperatures and open drought phenotyping facility, simulating the field conditions. LC-MS/MS based metabolite profiling was performed in flag leaves and spikelets of three cultivars contrasting for spikelet sterility and source (leaf weight) treated to drought, heat and combined stress. Constitutively regulated metabolites, metabolic signatures common to all stresses, cultivars and tissues, metabolites common to both the tissues across the stresses and cultivars and metabolites common to each cultivar across the tissues and stresses were identified. Under combined stress, metabolites differentially accumulated between cultivars contrasting for spikelet sterility but similar for source and cultivars contrasting for both spikelet sterility and source have been identified. These metabolites would serve as markers towards improving combined stress tolerance of rice.


Assuntos
Infertilidade , Oryza , Cromatografia Líquida , Secas , Ecossistema , Resposta ao Choque Térmico , Infertilidade/metabolismo , Folhas de Planta/metabolismo , Estresse Fisiológico , Espectrometria de Massas em Tandem
6.
J Sci Food Agric ; 102(14): 6491-6501, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35567417

RESUMO

BACKGROUND: Soil-dwelling human pathogens like Salmonella are transmitted by fresh produce such as tomato, spinach, onion and cabbage. With >2600 serovars, it is difficult to classify the good plant colonizers from the non-colonizers. Generally, soil microbiota are classified as autochthonous or zymogenous organisms, based on their ability to survive in soil. However, such information for soil-dwelling human pathogens is not available Thus there is a need to classify these organisms for designing a strategy to prevent their outbreak. Moreover, soil harbours a plethora of microbes, which can be screened for competitive organisms to control such human pathogens. RESULTS: In this study, we examined whether the morphotype based on the attachment factors (e.g., cellulose and curli fimbri) of Salmonella was important for its colonization of roots. Secondly, we tracked the location of the bacteria in the plant cell. Interestingly, most of the epidermal cells occupied by Salmonella showed propidium iodide-positive nuclei. As an extension of the study, a screening of competitive rhizospheric bacteria was performed. One isolate, identified as Lysinibacillus macroides, was able to inhibit the biofilm of Salmonella and subsequently reduced its colonization on roots. CONCLUSION: Based on this study, we classified the Rdar (red, dry and rough) morphotypes as good plant colonists. The ability to colonize and subsequent kill the live plant cell throws light on the zymogenous life cycle of soil-dwelling Salmonella. Additionally, Lysinibacillus macroides served as a biocontrol agent by reducing the burden of Salmonella in various vegetables. Such organisms can further be explored to prevent contamination of the food chain. © 2022 Society of Chemical Industry.


Assuntos
Celulose , Salmonella , Bacillaceae , Celulose/metabolismo , Humanos , Propídio , Solo
7.
Int J Mol Sci ; 22(21)2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34769121

RESUMO

Rice cultivated under rainfed or semi-irrigated ecosystems is frequently exposed to a combination of drought and heat stress. As a sensitive crop at the reproductive stage, exposure to combined drought and heat stress will have a deleterious effect on yield. In this study, two rice cultivars with contrasting spikelet sterility, AVT2-5315 (low sterility) and AC35027 (high sterility), under combined stress were selected for physiological characterization and phytohormonal profiling at anthesis. Under combined stress, both cultivars did not differ in the physiological parameters such as relative water content, photosynthetic rate, light-adapted chlorophyll fluorescence and biomass, suggesting a similar source activity under stress. However, AVT2-5315 showed better yield due to better pollen and spikelet fertility than AC35027, suggesting its intrinsic tolerance ability under combined stress. Targeted profiling of 15 phytohormones from drought, heat and combined stress-treated flag leaf and spikelet tissues using LC-MS/MS showed increased accumulation of auxins (indole 3-acetic acid and indole 3-butyric acid) in flag leaves and jasmonic acid in spikelets of AVT2-5315, while there was increased accumulation of ethylene in flag leaves and methyl-jasmonate in spikelets of AC35027. Increased accumulation of these hormones correlated with key biosynthetic pathway genes. In the flag leaves, increased accumulation of auxins was correlated with increased transcript levels of YUCCA-like gene 1 (OsYUCCA1) and fish bone (OsFIB), in AVT2-5315 under combined stress. In AC35027, increased ethylene content was correlated with expression of 1-aminocyclopropane-1-carboxylate synthase 1 (OsASC1) and aminocyclopropane-1-carboxylic acid oxidase 2 (OsACO2). Similarly, in spikelets, increased accumulation of jasmonic acid in AVT2-5315 was correlated with expression of allene oxide cyclase (OsAOC) and 12-oxophytodienoic acid reductase 1 (OsOPR1). The mechanism of regulating spikelet sterility by these hormones needs further investigation towards improving rice tolerance to combined stress.


Assuntos
Resposta ao Choque Térmico , Oryza/metabolismo , Osmorregulação , Reguladores de Crescimento de Plantas/metabolismo , Infertilidade das Plantas
8.
Front Plant Sci ; 12: 654512, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34408757

RESUMO

Pre-sowing seed treatment with systemic fungicides is a firmly entrenched practice for most agricultural crops worldwide. The treatment is intended to protect the crop against seed- and soil-borne diseases. In recent years, there is increasing evidence that fungicidal applications to manage diseases might inadvertently also affect non-target organisms, such as endophytes. Endophytes are ubiquitously present in plants and contribute to plant growth and development besides offering resistance to biotic and abiotic stresses. In seeds, endophytes may play a role in seed development, seed germination, seedling establishment and crop performance. In this paper, we review the recent literature on non-target effects of fungicidal applications on endophytic fungal community and discuss the possible consequences of indiscriminate seed treatment with systemic fungicide on seed endophytes. It is now well recognized that endophytes are ubiquitously present in all parts of the plant, including the seeds. They may be transmitted vertically from seed to seed as in many grasses and/or acquired horizontally from the soil and the environment. Though the origins and evolution of these organisms in plants are a matter of conjecture, numerous studies have shown that they symbiotically aid in plant growth and development, in nutrient acquisition as well in protecting the plants from abiotic and biotic stresses. Against this background, it is reasonable to assume that the use of systemic fungicides in seed treatment may not only affect the seed endophytes but also their attendant benefits to seedling growth and establishment. While there is evidence to indicate that fungicidal applications to manage plant diseases also affect foliar endophytes, there are only few studies that have documented the effect of seed treatment on seed-borne endophytes. Some of the convincing examples of the latter come from studies on the effect of fungicide application on rye grass seed endophyte AR37. More recently, experiments have shown that removal of seed endophytes by treatment with systemic fungicides leads to significant loss of seedling vigour and that such losses could be partially restored by enriching the seedlings with the lost endophytes. Put together, these studies reinforce the importance of seed endophytes to seedling growth and establishment and draw attention on how to trade the balance between the benefits of seed treatments and the direct and indirect costs incurred due to loss of endophytes. Among several approaches, use of reduced-risk fungicides and identifying fungicide-resistant endophytes are suggested to sustain the endophyte contribution to early seedling growth.

9.
Microorganisms ; 9(6)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201292

RESUMO

Phosphate (Pi) availability has a strong influence on the symbiotic interaction between Arabidopsis and a recently described root-colonizing beneficial Trichoderma harzianum strain. When transferred to media with insoluble Ca3(PO4)2 as a sole Pi source, Arabidopsis seedlings died after 10 days. Trichoderma grew on the medium containing Ca3(PO4)2 and the fungus did colonize in roots, stems, and shoots of the host. The efficiency of the photosynthetic electron transport of the colonized seedlings grown on Ca3(PO4)2 medium was reduced and the seedlings died earlier, indicating that the fungus exerts an additional stress to the plant. Interestingly, the fungus initially alleviated the Pi starvation response and did not activate defense responses against the hyphal propagation. However, in colonized roots, the sucrose transporter genes SWEET11 and -12 were strongly down-regulated, restricting the unloading of sucrose from the phloem parenchyma cells to the apoplast. Simultaneously, up-regulation of SUC1 promoted sucrose uptake from the apoplast into the parenchyma cells and of SWEET2 sequestration of sucrose in the vacuole of the root cells. We propose that the fungus tries to escape from the Ca3(PO4)2 medium and colonizes the entire host. To prevent excessive sugar consumption by the propagating hyphae, the host restricts sugar availability in its apoplastic root space by downregulating sugar transporter genes for phloem unloading, and by upregulating transporter genes which maintain the sugar in the root cells.

10.
3 Biotech ; 11(2): 64, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33489682

RESUMO

The study aims at investigating the growth and development of two common pests in mulberry namely the leaf roller (Diaphania pulverulentalis) and mealy bug (Macconellicoccus hirsutus), reared on transgenic mulberry plants in comparison with the wild type plants V1, a ruling variety. Both the pests completed normal life cycle on all the four different transgenic plants (Ip::HVA1, Cp::HVA1, Cp::BCH1, Cp::osmotin and Ip::osmotin) expressing three different transgenes (HVA1, BCH1 and osmotin) in the presence of the marker gene NPTII. There was no significant difference in the incubation period of the eggs, growth of first to fifth instar larvae and total larval period of the leaf roller reared on transgenic and non-transgenic mulberry. The pre-pupal, pupal, adult stages and adult fecundity also did not differ. The variations in the duration of the different nymphal instars, and their total duration was not significant in the case of mealy bug, when reared on the transgenics. The adult longevity and total life span of female mealy bugs, and the pupal period and total life span of the male bugs were on par with those reared on the wild type plants. The study indicates that the life cycle of both the pests, which are common in a mulberry ecosystem, were not affected by feeding on any of the transgenic mulberry plants at any stage of their growth and development.

11.
Front Plant Sci ; 11: 561007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193487

RESUMO

Endophytes are non-disease causing microbes (bacteria and fungi) surviving in living tissues of plants. Their intimate association and possible coevolution with their plant partners have resulted in them contributing to an array of plant growth benefits ranging from enhanced growth and biomass accumulation, tolerance to abiotic and biotic stresses and in nutrient acquisition. The last couple of decades have witnessed a burgeoning literature on the role of endophytes (Class 3 type) in regulating plant growth and development and their adaptation to abiotic and biotic stresses. Though the underlying mechanisms of plant-endophyte interactions are far from clear, several studies have raised the hope of their potential application in agriculture, especially in mitigating abiotic and biotic stresses. The use of endophytes is envisaged as a route to reduce the production cost and burden on the environment by lessening the dependence on breeding for crop improvement and agrochemicals. Unfortunately, save a few well documented examples of their use, a little of these insights has been translated into actual agricultural applications. Here, we reflect on this paucity and elaborate on some of the important bottlenecks that might stand in way of fully realizing the potential that endophytes hold for crop improvement. We stress the need to study various facets of the endophyte-plant association for their gainful application in agriculture.

12.
Trends Ecol Evol ; 35(11): 965-968, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32958363

RESUMO

Plant domestication, at least in cereals, is associated with the loss of the shattering allele. In such species, grains are manually harvested and threshed, leaving behind naked seeds. This could have led to the loss of maternally borne seed microbiomes and their associated benefits in modern-day domesticated species.


Assuntos
Cemitérios , Microbiota , Alelos , Domesticação
13.
Sci Rep ; 10(1): 3237, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32094443

RESUMO

Endophytes, both of bacterial and fungal origin, are ubiquitously present in all plants. While their origin and evolution are enigmatic, there is burgeoning literature on their role in promoting growth and stress responses in their hosts. We demonstrate that a salt-tolerant endophyte isolated from salt-adapted Pokkali rice, a Fusarium sp., colonizes the salt-sensitive rice variety IR-64, promotes its growth under salt stress and confers salinity stress tolerance to its host. Physiological parameters, such as assimilation rate and chlorophyll stability index were higher in the colonized plants. Comparative transcriptome analysis revealed 1348 up-regulated and 1078 down-regulated genes in plants colonized by the endophyte. Analysis of the regulated genes by MapMan and interaction network programs showed that they are involved in both abiotic and biotic stress tolerance, and code for proteins involved in signal perception (leucine-rich repeat proteins, receptor-like kinases) and transduction (Ca2+ and calmodulin-binding proteins), transcription factors, secondary metabolism and oxidative stress scavenging. For nine genes, the data were validated by qPCR analysis in both roots and shoots. Taken together, these results show that salt-adapted Pokkali rice varieties are powerful sources for the identification of novel endophytes, which can be used to confer salinity tolerance to agriculturally important, but salt-sensitive rice varieties.


Assuntos
Endófitos/fisiologia , Genes de Plantas , Oryza/genética , Oryza/microbiologia , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Endófitos/efeitos dos fármacos , Endófitos/isolamento & purificação , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Anotação de Sequência Molecular , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Potássio/metabolismo , Mapas de Interação de Proteínas/genética , Controle de Qualidade , Reprodutibilidade dos Testes , Salinidade , Tolerância ao Sal/efeitos dos fármacos , Sódio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Transcriptoma/genética
14.
Front Plant Sci ; 11: 573670, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33424876

RESUMO

Plants host numerous endophytic microbes which promote plant performance, in particular under stress. A new endophytic fungus was isolated from the leaves of a deciduous wood tree Leucas aspera. Morphological inspection and multilocus phylogeny identified the fungus as a new Trichoderma strain. If applied to Arabidopsis thaliana and Nicotiana attenuata, it mainly colonizes their roots and strongly promotes initial growth of the plants on soil. The fungus grows on high NaCl or mannitol concentrations, and shows predatory capability on the pathogenic fungus Alternaria brassicicola. Colonized Arabidopsis plants tolerate higher salt stress and show lower A. brassicicola spread in roots and shoots, while arbuscular mycorrhiza formation in N. attenuata is not affected by the Trichoderma strain. These beneficial features of the novel Trichoderma strain are important prerequisites for agricultural applications.

15.
J Genet ; 98(2)2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31204698

RESUMO

Finger millet (Eleusine coracana (L.) Gaertn.), an important C4 species is known for its stress hardiness and nutritional significance. To identify novel drought responsive mechanisms, we generated transcriptome data from leaf tissue of finger millet, variety GPU-28, exposed to gravimetrically imposed drought stress so as to simulate field stress conditions. De novo assembly based approach yielded 80,777 and 90,830 transcripts from well-irrigated (control) and drought-stressed samples, respectively. A total of 1790 transcripts were differentially expressed between the control and drought-stress treatments. Functional annotation and pathway analysis indicated activation of diverse drought-stress signalling cascade genes such as serine threonine protein phosphatase 2A (PP2A), calcineurin B-like interacting protein kinase31 (CIPK31), farnesyl pyrophosphate synthase (FPS), signal recognition particle receptor α (SRPR α) etc. The basal regulatory genes such as TATA-binding protein (TBP)-associated factors (TAFs) werefound to be drought responsive, indicating that genes associated with housekeeping or basal regulatory processes are activated underdrought in finger millet. A significant portion of the expressed genes was uncharacterized, belonging to the category of proteins of unknown functions (PUFs). Among the differentially expressed PUFs, we attempted to assign putative function for a few, using anovel annotation tool, Proteins of Unknown Function Annotation Server. Analysis of PUFs led to the discovery of novel drought responsive genes such as pentatricopeptide repeat proteins and tetratricopeptide repeat proteins that serve as interaction modules in multiprotein interactions. The transcriptome data generated can be utilized for comparative analysis, and functional validation of the genes identified would be useful to understand the drought adaptive mechanisms operating under field conditions in finger millet, as has been already attempted for a few candidates such as CIPK31 and TAF6. Such an attempt is needed to enhance the productivity of finger millet under water-limited conditions, and/or to adopt the implicated mechanisms in other related crops.


Assuntos
Adaptação Biológica/genética , Secas , Eleusine/genética , Perfilação da Expressão Gênica , Estresse Fisiológico/genética , Transcriptoma , Biologia Computacional/métodos , Regulação da Expressão Gênica de Plantas , Genômica/métodos , Anotação de Sequência Molecular
16.
BMC Plant Biol ; 18(1): 344, 2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30537948

RESUMO

BACKGROUND: Pre-harvest contamination of fruits and vegetables by Salmonella in fields is one of the causes of food-borne outbreaks. Natural openings like stomata, hydathodes and fruit cracks are known to serve as entry points. While there are reports indicating that Salmonella colonize and enter root through lateral root emerging area, further investigations regarding how the accessibility of Salmonella to lateral root is different from phyto-pathogenic bacteria, the efficacy of lateral root to facilitate entry have remained unexplored. In this study we attempted to investigate the lateral root mediated entry of Salmonella, and to bridge this gap in knowledge. RESULTS: Unlike phytopathogens, Salmonella cannot utilize cellulose as the sole carbon source. This negates the fact of active entry by degrading plant cellulose and pectin. Endophytic Salmonella colonization showed a high correlation with number of lateral roots. When given equal opportunity to colonize the plants with high or low lateral roots, Salmonella internalization was found higher in the plants with more lateral roots. However, the epiphytic colonization in both these plants remained unaltered. To understand the ecological significance, we induced lateral root production by increasing soil salinity which made the plants susceptible to Salmonella invasion and the plants showed higher Salmonella burden in the aerial organs. CONCLUSION: Salmonella, being unable to degrade plant cell wall material relies heavily on natural openings. Therefore, its invasion is highly dependent on the number of lateral roots which provides an entry point because of the epidermis remodeling. Thus, when number of lateral root was enhanced by increasing the soil salinity, plants became susceptible to Salmonella invasion in roots and its transmission to aerial organs.


Assuntos
Contaminação de Alimentos , Raízes de Plantas/microbiologia , Salmonella/metabolismo , Doenças das Plantas/microbiologia , Salinidade
17.
3 Biotech ; 8(8): 345, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30073130

RESUMO

G-box-binding factors are plant transcription factors, involved in a wide range of biological processes including abiotic stress responses. In this study, we analyzed the expression of OsGBF1 during salt stress in two contrasting Oryza sativa spp. indica genotypes, Rasi and Tellahamsa. Two-day-old seedlings were exposed to NaCl stress under two different conditions. One set was exposed to 100 mM NaCl before transferring to 250 mM (induction stress), while another set was transferred directly to 250 mM (shock stress). During early induction stress, OsGBF1 was up-regulated in Rasi when compared to Tellahamsa. We cloned full-length OsGBF1 from these two genotypes, and analyzed the sequences. Our analysis indicated the presence of transcript variants, which are designated as OsGBF1a and 1b. OsGBF1b variant retained introns, which lead to the generation of premature termination codon. OsGBF1b transcript levels were not significantly different at 12-h of induction stress in Tellahamsa and Rasi. At 24-h of shock stress, OsGBF1b was up-regulated in both genotypes and the transcript was more in Rasi. Since, OsGBF1a and 1b are predicted to be splice variants, we examined expression pattern of OsSKIP, a splicing factor and component of the spliceosome. In induction stress, OsSKIP was up-regulated at 12- and 24-h in Rasi when compared to Tellahamsa. On the contrary, at 24-h shock stress, OsSKIP was down-regulated in Rasi when compared to Tellahamsa. It is possible that OsSKIP expression was increased in Rasi during induction stress for accurate splicing that could aid in tolerance. This is the first report on OsGBF1 splice variant and the variant could have specific functions linked to stress tolerance in rice.

18.
DNA Res ; 25(1): 39-47, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28985356

RESUMO

Finger millet (Eleusine coracana (L.) Gaertn) is an important crop for food security because of its tolerance to drought, which is expected to be exacerbated by global climate changes. Nevertheless, it is often classified as an orphan/underutilized crop because of the paucity of scientific attention. Among several small millets, finger millet is considered as an excellent source of essential nutrient elements, such as iron and zinc; hence, it has potential as an alternate coarse cereal. However, high-quality genome sequence data of finger millet are currently not available. One of the major problems encountered in the genome assembly of this species was its polyploidy, which hampers genome assembly compared with a diploid genome. To overcome this problem, we sequenced its genome using diverse technologies with sufficient coverage and assembled it via a novel multiple hybrid assembly workflow that combines next-generation with single-molecule sequencing, followed by whole-genome optical mapping using the Bionano Irys® system. The total number of scaffolds was 1,897 with an N50 length >2.6 Mb and detection of 96% of the universal single-copy orthologs. The majority of the homeologs were assembled separately. This indicates that the proposed workflow is applicable to the assembly of other allotetraploid genomes.

19.
Phytomedicine ; 36: 160-167, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29157810

RESUMO

BACKGROUND: Camptothecin (CPT), a quinoline alkaloid, is a potent inhibitor of eukaryotic topoisomerase I. Because of this property, several derivatives of CPT are used as chemotherapeutic agents. CPT is produced by several plant species belonging to the Asterid clade as well as by a number of endophytic fungal associates of these plants. In this study, we report the production of CPT by four bacterial endophytes and show the possible role of a plasmid in the biosynthesis of CPT. METHODS: Endophytic bacteria were isolated from leaves, stems and fruits of Pyrenacantha volubilis Hook. (Icacinanceae). The bacterial isolates were purified and analyzed for production of CPT by ESI-MS/MS and NMR analysis. Bacterial identity was established based on the morphology and 16s rRNA sequence analysis. Crude extracts of the bacterial endophytes were evaluated for their cytotoxicity using colon cancer cell lines. The role of plasmid in the production of CPT was studied by purging the plasmid, using acriflavine, as well as reconstituting the bacteria with the plasmid. RESULTS: Four bacterial isolates, Bacillus sp. (KP125955 and KP125956), Bacillus subtilis (KY741853) and Bacillus amyloliquefaciens (KY741854) were found to produce CPT in culture. Both based on ESI-MS/MS and NMR analysis, the identity of CPT was found to be similar to that produced by the host plant. The CPT was biologically active as evident by its cytotoxicity against colon cancer cell line. The production of CPT by the endophyte (Bacillus subtilis, KY741853) attenuated with sub-culture. A likely role of a plasmid in the production of CPT was established. A 5 kbp plasmid was recovered from the bacteria. Bacterial isolate cured of plasmid failed to produce CPT. CONCLUSION: Our study implies a possible role of a plasmid in the production of CPT by the endophytic bacteria and opens up further work to unravel the exact mechanisms that might be involved.


Assuntos
Bacillus/genética , Bacillus/metabolismo , Camptotecina/biossíntese , Magnoliopsida/microbiologia , Plasmídeos , Antineoplásicos/farmacologia , Bacillus/isolamento & purificação , Camptotecina/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Endófitos/isolamento & purificação , Frutas/microbiologia , Humanos , Folhas de Planta/microbiologia , RNA Ribossômico 16S , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
20.
Sci Rep ; 7(1): 9148, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28831141

RESUMO

Drought transcriptome analysis of finger millet (Eleusine coracana) by cDNA subtraction identified drought responsive genes that have a potential role in drought tolerance. Through virus-induced gene silencing (VIGS) in a related crop species, maize (Zea mays), several genes, including a G-BOX BINDING FACTOR 3 (GBF3) were identified as candidate drought stress response genes and the role of GBF3 in drought tolerance was studied in Arabidopsis thaliana. Overexpression of both EcGBF3 and AtGBF3 in A. thaliana resulted in improved tolerance to osmotic stress, salinity and drought stress in addition to conferring insensitivity to ABA. Conversely, loss of function of this gene increased the sensitivity of A. thaliana plants to drought stress. EcGBF3 transgenic A. thaliana results also suggest that drought tolerance of sensitive plants can be improved by transferring genes from far related crops like finger millet. Our results demonstrate the role of GBF3 in imparting drought tolerance in A. thaliana and indicate the conserved role of this gene in drought and other abiotic stress tolerance in several plant species.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Fatores de Ligação G-Box/genética , Estresse Fisiológico , Arabidopsis/genética , Secas , Eleusine/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas de Plantas/genética , Técnicas de Hibridização Subtrativa , Zea mays/genética
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