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1.
BMC Plant Biol ; 21(1): 404, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488625

RESUMO

BACKGROUND: Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. RESULTS: Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. CONCLUSIONS: The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.


Assuntos
Brassica/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Folhas de Planta/metabolismo , Estresse Fisiológico , Temperatura Alta
2.
BMC Plant Biol ; 21(1): 416, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507525

RESUMO

BACKGROUND: Leaf color variation is a common trait in plants and widely distributed in many plants. In this study, a leaf color mutation in Camellia japonica (cultivar named as Maguxianzi, M) was used as material, and the mechanism of leaf color variation was revealed by physiological, cytological, transcriptome and microbiome analyses. RESULTS: The yellowing C. japonica (M) exhibits lower pigment content than its parent (cultivar named as Huafurong, H), especially chlorophyll (Chl) and carotenoid, and leaves of M have weaker photosynthesis. Subsequently, the results of transmission electron microscopy(TEM) exhibited that M chloroplast was accompanied by broken thylakoid membrane, degraded thylakoid grana, and filled with many vesicles. Furthermore, comparative transcriptome sequencing identified 3,298 differentially expressed genes (DEGs). KEGG annotation analysis results showed that 69 significantly enriched DEGs were involved in Chl biosynthesis, carotenoid biosynthesis, photosynthesis, and plant-pathogen interaction. On this basis, we sequenced the microbial diversity of the H and M leaves. The sequencing results suggested that the abundance of Didymella in the M leaves was significantly higher than that in the H leaves, which meant that M leaves might be infected by Didymella. CONCLUSIONS: Therefore, we speculated that Didymella infected M leaves while reduced Chl and carotenoid content by damaging chloroplast structures, and altered the intensity of photosynthesis, thereby causing the leaf yellowing phenomenon of C. japonica (M). This research will provide new insights into the leaf color variation mechanism and lay a theoretical foundation for plant breeding and molecular markers.


Assuntos
Camellia/anatomia & histologia , Camellia/genética , Camellia/metabolismo , Cor , Microbiota , Folhas de Planta/anatomia & histologia , Folhas de Planta/metabolismo , Carotenoides/metabolismo , China , Clorofila/metabolismo , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Variação Genética , Genótipo , Fenótipo , Transcriptoma
3.
Planta ; 254(4): 76, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34533642

RESUMO

MAIN CONCLUSION: A new molecular mechanism of tetrahydrofolate deformylase involved in the salt response presumably affects mitochondrial and chloroplast function by regulating energy metabolism and accumulation of reactive oxygen species. High salinity severely restrains plant growth and development, consequently leading to a reduction in grain yield. It is therefore critical to identify the components involved in plant salt resistance. In our previous study, we identified a rice leaf early-senescence mutant hpa1, which encodes a formyl tetrahydrofolate deformylase (Xiong et al. in Sci China Life Sci 64(5):720-738, 2021). Here, we report that HPA1 also plays a role in the salt response. To explore the molecular mechanism of HPA1 in salt resistance, we attempted to identify the differentially expressed proteins between wild type and hpa1 mutant for salinity treatment using an iTRAQ-based comparative protein quantification approach. A total of 4598 proteins were identified, of which 279 were significantly altered, including 177 up- and 102 down-regulated proteins. A functional analysis suggested that the 279 differentially expressed proteins are involved mainly in the regulation of oxidative phosphorylation, phenylpropanoid biosynthesis, photosynthesis, posttranslational modifications, protein turnover and energy metabolism. Moreover, a deficiency in HPA1 impaired chlorophyll metabolism and photosynthesis in chloroplasts and affected the electron flow of the electron transport chain in mitochondria. These changes led to abnormal energy metabolism and accumulation of reactive oxygen species, which may affect the permeability and integrity of cell membranes, leading to cell death. In addition, the results were verified by transcriptional or physiological experiments. Our results provide an insight into a new molecular mechanism of the tetrahydrofolate cycle protein formyl tetrahydrofolate deformylase, which is involved in the salt response, presumably by affecting mitochondrial and chloroplast function regulating energy metabolism and accumulation of reactive oxygen species under salt stress.


Assuntos
Oryza , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteômica , Tetra-Hidrofolatos
4.
Planta ; 254(3): 54, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34410495

RESUMO

MAIN CONCLUSION: The expression of full-length cDNAs encoding lavender AGAMOUS-like (LaAG-like) and SEPALLATA3-like (LaSEP3-like) transcription factors induces early flowering and impacts the leaf morphology at a strong expression level in Arabidopsis. Lavandula angustifolia is widely cultivated as an ornamental plant due to its attractive flower structure, and as a source of valuable essential oils for use in cosmetics, alternative medicines, and culinary products. We recently employed RNA-Seq and transcript profiling to describe a number of transcription factors (TFs) that potentially control flower development in this plant. In this study, we investigated the roles of two TFs, LaAGAMOUS-like (LaAG-like) and LaSEPALLATA3-like (LaSEP3-like), that exhibited substantial homology to Arabidopsis thaliana floral development genes, AGAMOUS and SEPALLATA3, respectively, in flowering initiation in Arabidopsis. We stably and constitutively expressed LaAG-like and LaSEP3-like cDNAs in separate Arabidopsis plants. All transgenic plants flowered earlier than the wild-type controls. However, plants that modestly overexpressed the gene were phenotypically normal, while those that strongly expressed the transgene developed curly leaves. We also assessed the expression of five endogenous flowering time regulating genes, from which high expression of Flowering Locus T (AtFT) mRNA in both LaAG-like (type-I and -II) and LaSEP3-like (type-I), and Leafy (AtLFY) mRNAs in LaSEP3-like (type-I) transgenic plants were detected, compared to wild-type controls. Our results suggest that with controlled expression, lavender AG-like and SEP3-like genes are potentially useful for the regulation of flowering time in commercial lavender species, and could be used for plant improvement studies through molecular genetics and targeted breeding programs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Lavandula , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Lavandula/metabolismo , Proteínas de Domínio MADS/genética , Melhoramento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Proteínas Repressoras
5.
Molecules ; 26(15)2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34361835

RESUMO

The present study compared the effects of natural senescence and methyl jasmonate (JA-Me) treatment on the levels of terpene trilactones (TTLs; ginkgolides and bilobalide), phenolic acids, and flavonoids in the primary organs of Ginkgo biloba leaves, leaf blades, and petioles. Levels of the major TTLs, ginkgolides B and C, were significantly higher in the leaf blades of naturally senesced yellow leaves harvested on 20 October compared with green leaves harvested on 9 September. In petioles, a similar effect was found, although the levels of these compounds were almost half as high. These facts indicate the importance of the senescence process on TTL accumulation. Some flavonoids and phenolic acids also showed changes in content related to maturation or senescence. Generally, the application of JA-Me slightly but substantially increased the levels of TTLs in leaf blades irrespective of the difference in its application side on the leaves. Of the flavonoids analyzed, levels of quercetin, rutin, quercetin-4-glucoside, apigenin, and luteolin were dependent on the JA-Me application site, whereas levels of (+) catechin and (-) epicatechin were not. Application of JA-Me increased ferulic acid and p-coumaric acid esters in the petiole but decreased the levels of these compounds in the leaf blade. The content of p-coumaric acid glycosides and caffeic acid esters was only slightly modified by JA-Me. In general, JA-Me application affected leaf senescence by modifying the accumulation of ginkogolides, flavonoids, and phenolic acids. These effects were also found to be different in leaf blades and petioles. Based on JA-Me- and aging-related metabolic changes in endogenous levels of the secondary metabolites in G. biloba leaves, we discussed the results of study in the context of basic research and possible practical application.


Assuntos
Senescência Celular , Ciclopentanos/farmacologia , Flavonoides/metabolismo , Ginkgo biloba/metabolismo , Hidroxibenzoatos/metabolismo , Lactonas/metabolismo , Oxilipinas/farmacologia , Folhas de Planta/metabolismo , Flavonoides/análise , Ginkgo biloba/efeitos dos fármacos , Ginkgo biloba/crescimento & desenvolvimento , Hidroxibenzoatos/análise , Lactonas/análise , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Terpenos/análise , Terpenos/metabolismo
6.
Nat Commun ; 12(1): 4866, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381045

RESUMO

Plants invest a considerable amount of leaf nitrogen in the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO), forming a strong coupling of nitrogen and photosynthetic capacity. Variability in the nitrogen-photosynthesis relationship indicates different nitrogen use strategies of plants (i.e., the fraction nitrogen allocated to RuBisCO; fLNR), however, the reason for this remains unclear as widely different nitrogen use strategies are adopted in photosynthesis models. Here, we use a comprehensive database of in situ observations, a remote sensing product of leaf chlorophyll and ancillary climate and soil data, to examine the global distribution in fLNR using a random forest model. We find global fLNR is 18.2 ± 6.2%, with its variation largely driven by negative dependence on leaf mass per area and positive dependence on leaf phosphorus. Some climate and soil factors (i.e., light, atmospheric dryness, soil pH, and sand) have considerable positive influences on fLNR regionally. This study provides insight into the nitrogen-photosynthesis relationship of plants globally and an improved understanding of the global distribution of photosynthetic potential.


Assuntos
Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Clorofila/metabolismo , Clima , Ecossistema , Internacionalidade , Modelos Teóricos , Fósforo/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Solo/química
7.
Molecules ; 26(15)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34361600

RESUMO

Persistent pollutants such as pharmaceuticals, pesticides, musk fragrances, and dyes are frequently detected in different environmental compartments and negatively impact the environment and humans. Understanding the impacts of diffuse environmental pollutants on plants is still limited, especially at realistic environmental concentrations of contaminants. We studied the effects of key representatives of two major classes of environmental pollutants (nine different antibiotics and six different textile dyes) on the leaf carotenoid (violaxanthin and neoxanthin) content in wheat (Triticum aestivum L.) using different pollutant concentrations and application times. The wheat plants were watered with solutions of selected environmental pollutants in two different concentrations of 0.5 mg L-1 and 1.5 mg L-1 for one week (0.5 L) and two weeks (1 L). Both categories of pollutants selected for this study negatively influenced the content of violaxanthin and neoxanthin, whereas the textile dyes represented more severe stress to the wheat plants. The results demonstrate that chronic exposure to common diffusively spread environmental contaminants constitutes significant stress to the plants.


Assuntos
Antibacterianos/toxicidade , Corantes/toxicidade , Poluentes Ambientais/toxicidade , Folhas de Planta/metabolismo , Triticum/metabolismo , Xantofilas/metabolismo
8.
J Agric Food Chem ; 69(34): 10002-10016, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34406741

RESUMO

Theanine and flavonoids (especially proanthocyanidins) are the most important and abundant secondary metabolites synthesized in the roots of tea plants. Nitrogen promotes theanine and represses flavonoid biosynthesis in tea plant roots, but the underlying mechanism is still elusive. Here, we analyzed theanine and flavonoid metabolism in tea plant roots under nitrogen deficiency and explored the regulatory mechanism using proteome and ubiquitylome profiling together with transcriptome data. Differentially expressed proteins responsive to nitrogen deficiency were identified and found to be enriched in flavonoid, nitrogen, and amino acid metabolism pathways. The proteins responding to nitrogen deficiency at the transcriptional level, translational level, and both transcriptional and translational levels were classified. Nitrogen-deficiency-responsive and ubiquitinated proteins were further identified. Our results showed that most genes encoding enzymes in the theanine synthesis pathway, such as CsAlaDC, CsGDH, and CsGOGATs, were repressed by nitrogen deficiency at transcriptional and/or protein level(s). While a large number of enzymes in flavonoid metabolism were upregulated at the transcriptional and/or translational level(s). Importantly, the ubiquitylomic analysis identified important proteins, especially the hub enzymes in theanine and flavonoid biosynthesis, such as CsAlaDC, CsTSI, CsGS, CsPAL, and CsCHS, modified by ubiquitination. This study provided novel insights into the regulation of theanine and flavonoid biosynthesis and will contribute to future studies on the post-translational regulation of secondary metabolism in tea plants.


Assuntos
Camellia sinensis , Nitrogênio , Camellia sinensis/genética , Camellia sinensis/metabolismo , Flavonoides , Regulação da Expressão Gênica de Plantas , Glutamatos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Chá
9.
J Plant Physiol ; 264: 153485, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34358945

RESUMO

Soil salinity is a global concern and often the primary factor contributing to land degradation, limiting crop growth and production. Alfalfa (Medicago sativa L.) is a low input high value forage legume with a wide adaptation. Examining the tissue-specific responses to salt stress will be important to understanding physiological changes of alfalfa. The responses of two alfalfa cultivars (salt tolerant 'Halo', salt intolerant 'Vernal') were studied for 12 weeks in five gradients of salt stress in a sand based hydroponic system in the greenhouse. The accumulation and localization of elements and organic compounds in different tissues of alfalfa under salt stress were evaluated using synchrotron beamlines. The pattern of chlorine accumulation for 'Halo' was: root > stem ~ leaf at 8 dSm-1, and root ~ leaf > stem at 12 dSm-1, potentially preventing toxic ion accumulation in leaf tissues. In contrast, for 'Vernal', it was leaf > stem ~ root at 8 dSm-1 and leaf > root ~ stem at 12 dSm-1. The distribution of chlorine in 'Halo' was relatively uniform in the leaf surface and vascular bundles of the stem. Amide concentration in the leaf and stem tissues was greater for 'Halo' than 'Vernal' at all salt gradients. This study determined that low ion accumulation in the shoot was a common strategy in salt tolerant alfalfa up to 8 dSm-1 of salt stress, which was then replaced by shoot tissue tolerance at 12 dSm-1.


Assuntos
Medicago sativa/metabolismo , Cálcio/análise , Cálcio/metabolismo , Cloro/análise , Cloro/metabolismo , Medicago sativa/química , Medicago sativa/fisiologia , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Caules de Planta/química , Caules de Planta/metabolismo , Caules de Planta/fisiologia , Potássio/análise , Potássio/metabolismo , Estresse Salino , Tolerância ao Sal , Sódio/análise , Sódio/metabolismo
10.
J Photochem Photobiol B ; 222: 112263, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34339994

RESUMO

The biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The destructive analysis of samples irradiated by the sun for 6 days at the end of October 2015 in Skierniewice (Poland) showed an increase of leaf flavonols by 82% with respect to controls. The treatment by a broadband UVB fluorescent lamp, with irradiance of 0.38 W m-2 in the 290-315 nm range (and 0.59 W m-2 in the UVA region) for 12 h per day at 17 °C along with a white light of about 20 µmol m-2 s-1, produced a flavonols increase of 58% with respect to controls. The kinetics of flavonols accumulation in response to the photochemical treatments was monitored with the FLAV non-destructive index. The initial FLAV rate under the sun was proportional to the daily radiation doses with a better correlation for the sun global irradiance (R2 = 0.973), followed by the UVA (R2 = 0.965) and UVB (R2 = 0.899) irradiance. The sunlight turned out to be more efficient than the UVB lamp in increasing the flavonols level of waste leaves, because of a significant role played by UVA and visible solar radiation in the regulation of the flavonoid accumulation in cabbage. The FLAV index increase induced on the adaxial leaf side was accompanied by a lower but still significant FLAV increase on the unirradiated abaxial side, likely due to a systemic signaling by mean of the long-distance movement of macromolecules. Our present investigation provides useful data for the optimization of postharvest photochemical protocols of cabbage waste valorization. It can represent a novel and alternative tool of vegetable waste management for the recovery of beneficial phytochemicals.


Assuntos
Brassica/efeitos da radiação , Luz , Brassica/química , Brassica/metabolismo , Clorofila/química , Cromatografia Líquida de Alta Pressão , Flavonóis/análise , Flavonóis/metabolismo , Armazenamento de Alimentos , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Espectrometria de Fluorescência , Raios Ultravioleta
11.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360953

RESUMO

Cadmium (Cd), a heavy metal toxic to humans, easily accumulates in rice grains. Rice with unacceptable Cd content has become a serious food safety problem in many rice production regions due to contaminations by industrialization and inappropriate waste management. The development of rice varieties with low grain Cd content is seen as an economic and long-term solution of this problem. The cation/H+ exchanger (CAX) family has been shown to play important roles in Cd uptake, transport and accumulation in plants. Here, we report the characterization of the rice CAX family. The six rice CAX genes all have homologous genes in Arabidopsis thaliana. Phylogenetic analysis identified two subfamilies with three rice and three Arabidopsis thaliana genes in both of them. All rice CAX genes have trans-member structures. OsCAX1a and OsCAX1c were localized in the vacuolar while OsCAX4 were localized in the plasma membrane in rice cell. The consequences of qRT-PCR analysis showed that all the six genes strongly expressed in the leaves under the different Cd treatments. Their expression in roots increased in a Cd dose-dependent manner. GUS staining assay showed that all the six rice CAX genes strongly expressed in roots, whereas OsCAX1c and OsCAX4 also strongly expressed in rice leaves. The yeast (Saccharomyces cerevisiae) cells expressing OsCAX1a, OsCAX1c and OsCAX4 grew better than those expressing the vector control on SD-Gal medium containing CdCl2. OsCAX1a and OsCAX1c enhanced while OsCAX4 reduced Cd accumulation in yeast. No auto-inhibition was found for all the rice CAX genes. Therefore, OsCAX1a, OsCAX1c and OsCAX4 are likely to involve in Cd uptake and translocation in rice, which need to be further validated.


Assuntos
Antiporters/metabolismo , Cádmio/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Resistência a Medicamentos , Oryza/genética , Proteínas de Plantas/metabolismo , Antiporters/genética , Cádmio/toxicidade , Proteínas de Transporte de Cátions/genética , Transporte de Íons , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
12.
Phytochemistry ; 191: 112911, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34418773

RESUMO

The pleiotropic effects of zinc deficiency on ion homeostasis have already been described in several plants. Tobacco (Nicotiana tabacum) heavy metal ATPases HMA4.1 and HMA4.2 are involved in zinc and cadmium root-to-shoot translocation. In previous research, we have shown that N. tabacum HMA4 RNAi plants and HMA4 double-nonsense mutants exhibit strongly reduced zinc and cadmium levels in leaves as well as stunted growth. In this study, the ionome and transcriptome of these lines were investigated to better characterize the effect of reduced zinc levels and to understand the impaired growth phenotype. We found that, under standard greenhouse fertilization rates, these lines accumulated up to 4- to 6-fold more phosphorus, iron, manganese, and copper than their respective controls. Under field conditions, HMA4 double-mutant plants also exhibited similar accumulation phenotypes, albeit to a lower extent. In both HMA4 RNAi plants and HMA4 mutants, transcription analysis showed a local zinc-deficiency response in leaves as well as an FIT1-mediated iron-deficiency response in roots, likely contributing to iron and manganese uptake at the root level. A phosphate-starvation response involving HHO2 was also observed in HMA4-impaired plant leaves. The high level of phosphorus observed in HMA4-impaired plants is correlated with leaf swelling and necrosis. The upregulation of aquaporin genes is in line with cellular water influx and the observed leaf swelling phenotype. These results highlight the involvement of HMA4 in zinc homeostasis and related regulatory processes that balance the micro- and macroelements in above-ground organs.


Assuntos
Cádmio , Tabaco , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Cádmio/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Tabaco/metabolismo , Zinco/metabolismo
13.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360920

RESUMO

Barley is characterized by a rich genetic diversity, making it an important model for studies of salinity response with great potential for crop improvement. Moreover, salt stress severely affects barley growth and development, leading to substantial yield loss. Leaf and root transcriptomes of a salt-tolerant Tunisian landrace (Boulifa) exposed to 2, 8, and 24 h salt stress were compared with pre-exposure plants to identify candidate genes and pathways underlying barley's response. Expression of 3585 genes was upregulated and 5586 downregulated in leaves, while expression of 13,200 genes was upregulated and 10,575 downregulated in roots. Regulation of gene expression was severely impacted in roots, highlighting the complexity of salt stress response mechanisms in this tissue. Functional analyses in both tissues indicated that response to salt stress is mainly achieved through sensing and signaling pathways, strong transcriptional reprograming, hormone osmolyte and ion homeostasis stabilization, increased reactive oxygen scavenging, and activation of transport and photosynthesis systems. A number of candidate genes involved in hormone and kinase signaling pathways, as well as several transcription factor families and transporters, were identified. This study provides valuable information on early salt-stress-responsive genes in roots and leaves of barley and identifies several important players in salt tolerance.


Assuntos
Hordeum/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Tolerância ao Sal , Transcriptoma , Regulação da Expressão Gênica de Plantas
14.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445541

RESUMO

Mallotus japonicus is a valuable traditional medicinal plant in East Asia for applications as a gastrointestinal drug. However, the molecular components involved in the biosynthesis of bioactive metabolites have not yet been explored, primarily due to a lack of omics resources. In this study, we established metabolome and transcriptome resources for M. japonicus to capture the diverse metabolite constituents and active transcripts involved in its biosynthesis and regulation. A combination of untargeted metabolite profiling with data-dependent metabolite fragmentation and metabolite annotation through manual curation and feature-based molecular networking established an overall metabospace of M. japonicus represented by 2129 metabolite features. M. japonicus de novo transcriptome assembly showed 96.9% transcriptome completeness, representing 226,250 active transcripts across seven tissues. We identified specialized metabolites biosynthesis in a tissue-specific manner, with a strong correlation between transcripts expression and metabolite accumulations in M. japonicus. The correlation- and network-based integration of metabolome and transcriptome datasets identified candidate genes involved in the biosynthesis of key specialized metabolites of M. japonicus. We further used phylogenetic analysis to identify 13 C-glycosyltransferases and 11 methyltransferases coding candidate genes involved in the biosynthesis of medicinally important bergenin. This study provides comprehensive, high-quality multi-omics resources to further investigate biological properties of specialized metabolites biosynthesis in M. japonicus.


Assuntos
Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Mallotus (Planta)/metabolismo , Metaboloma , Proteínas de Plantas/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Mallotus (Planta)/genética , Mallotus (Planta)/crescimento & desenvolvimento , Especificidade de Órgãos , Filogenia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo
15.
Nat Commun ; 12(1): 5042, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413297

RESUMO

Food production must increase significantly to sustain a growing global population. Reducing plant water loss may help achieve this goal and is especially relevant in a time of climate change. The plant cuticle defends leaves against drought, and so understanding water movement through the cuticle could help future proof our crops and better understand native ecology. Here, via mathematical modelling, we identify mechanistic properties of water movement in cuticles. We model water sorption in astomatous isolated cuticles, utilising three separate pathways of cellulose, aqueous pores and lipophilic. The model compares well to data both over time and humidity gradients. Sensitivity analysis shows that the grouping of parameters influencing plant species variations has the largest effect on sorption, those influencing cellulose are very influential, and aqueous pores less so but still relevant. Cellulose plays a significant role in diffusion and adsorption in the cuticle and the cuticle surfaces.


Assuntos
Celulose/metabolismo , Plantas/metabolismo , Água/metabolismo , Adsorção , Transporte Biológico , Difusão , Secas , Umidade , Modelos Biológicos , Permeabilidade , Epiderme Vegetal/metabolismo , Folhas de Planta/metabolismo
16.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445145

RESUMO

The main goal of growing plants under various photoperiods is to optimize photosynthesis for using the effect of day length that often acts on plants in combination with biotic and/or abiotic stresses. In this study, Brassica juncea plants were grown under four different day-length regimes, namely., 8 h day/16 h night, 12 h day/12 h night, 16 h day/8 h night, and continuous light, and were infected with a necrotrophic fungus Alternaria brassicicola. The development of necroses on B. juncea leaves was strongly influenced by leaf position and day length. The largest necroses were formed on plants grown under a 16 h day/8 h night photoperiod at 72 h post-inoculation (hpi). The implemented day-length regimes had a great impact on leaf morphology in response to A. brassicicola infection. They also influenced the chlorophyll and carotenoid contents and photosynthesis efficiency. Both the 1st (the oldest) and 3rd infected leaves showed significantly higher minimal fluorescence (F0) compared to the control leaves. Significantly lower values of other investigated chlorophyll a fluorescence parameters, e.g., maximum quantum yield of photosystem II (Fv/Fm) and non-photochemical quenching (NPQ), were observed in both infected leaves compared to the control, especially at 72 hpi. The oldest infected leaf, of approximately 30% of the B. juncea plants, grown under long-day and continuous light conditions showed a 'green island' phenotype in the form of a green ring surrounding an area of necrosis at 48 hpi. This phenomenon was also reflected in changes in the chloroplast's ultrastructure and accelerated senescence (yellowing) in the form of expanding chlorosis. Further research should investigate the mechanism and physiological aspects of 'green islands' formation in this pathosystem.


Assuntos
Alternaria/patogenicidade , Mostardeira/microbiologia , Mostardeira/fisiologia , Necrose/microbiologia , Necrose/patologia , Fotossíntese/fisiologia , Doenças das Plantas/microbiologia , Carotenoides/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Fluorescência , Mostardeira/metabolismo , Necrose/metabolismo , Fotoperíodo , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia
17.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361121

RESUMO

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.


Assuntos
Ritmo Circadiano , Etilenos/farmacologia , Lycopersicon esculentum/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
18.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
19.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360554

RESUMO

Leaf angle and grain size are important agronomic traits affecting rice productivity directly and/or indirectly through modulating crop architecture. OsBC1, as a typical bHLH transcription factor, is one of the components comprising a complex formed with LO9-177 and OsBUL1 contributing to modulation of rice leaf inclination and grain size. In the current study, two homologues of OsBC1, OsBCL1 and OsBCL2 were functionally characterized by expressing them under the control of OsBUL1 promoter, which is preferentially expressed in the lamina joint and the spikelet of rice. Increased leaf angle and grain length with elongated cells in the lamina joint and the grain hull were observed in transgenic rice containing much greater gibberellin A3 (GA3) levels than WT, demonstrating that both OsBCL1 and OsBCL2 are positive regulators of cell elongation at least partially through increased GA biosynthesis. Moreover, the cell elongation was likely due to cell expansion rather than cell division based on the related gene expression and, the cell elongation-promoting activities of OsBCL1 and OsBCL2 were functional in a dicot species, Arabidopsis.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/anatomia & histologia , Fenótipo , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
20.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360556

RESUMO

In grapevines, as in other plants, sucrose and its constituents glucose and fructose are fundamentally important and carry out a multitude of roles. The aims of this review are three-fold. First, to provide a summary of the metabolism and transport of sucrose in grapevines, together with new insights and interpretations. Second, to stress the importance of considering the compartmentation of metabolism. Third, to outline the key role of acid invertase in osmoregulation associated with sucrose metabolism and transport in plants.


Assuntos
Metabolismo dos Carboidratos , Frutas/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Sacarose/metabolismo , Vitis/metabolismo , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Vitis/crescimento & desenvolvimento
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