Polyamines in Plant Biotechnology, Food Nutrition, and Human Health

Polyamines are small polycations derived from arginine and/or ornithine. These compounds are present in all living organisms and play common and organism-specific functions. Polyamines are present in most food products of plant and animal origin, thus having an impact on human nutrition and health. In this Topic, we aimed to cover both basic and applied research on polyamines in the areas of plant biotechnology, food nutrition, and human health

Molecular and metabolic mechanisms associated with fleshy fruit quality

Funding to AF was provided by the Portuguese Foundation for Science and Technology (FCT Investigator IF/00169/2015, PEst-OE/BIA/UI4046/2014). Research in the AG lab was supported by the EC H2020 Program:TRADITOM-634561 and TOMGEM679796 and networking activities by COST FA1106.Fortes, AM.; Granell Richart, A.; Pezzotti, M.; Bouzayen, M. (2017). Molecular and metabolic mechanisms associated with fleshy fruit quality. Frontiers in Plant Science. 8:6-10. https://doi.org/10.3389/fpls.2017.01236S6108Agudelo-Romero, P., Erban, A., Sousa, L., Pais, M. S., Kopka, J., & Fortes, A. M. (2013). Search for Transcriptional and Metabolic Markers of Grape Pre-Ripening and Ripening and Insights into Specific Aroma Development in Three Portuguese Cultivars. PLoS ONE, 8(4), e60422. doi:10.1371/journal.pone.0060422Fortes, A. M., & Gallusci, P. (2017). Plant Stress Responses and Phenotypic Plasticity in the Epigenomics Era: Perspectives on the Grapevine Scenario, a Model for Perennial Crop Plants. Frontiers in Plant Science, 08. doi:10.3389/fpls.2017.00082Fortes, A., Teixeira, R., & Agudelo-Romero, P. (2015). Complex Interplay of Hormonal Signals during Grape Berry Ripening. Molecules, 20(5), 9326-9343. doi:10.3390/molecules20059326Liu, R., How-Kit, A., Stammitti, L., Teyssier, E., Rolin, D., Mortain-Bertrand, A., … Gallusci, P. (2015). A DEMETER-like DNA demethylase governs tomato fruit ripening. Proceedings of the National Academy of Sciences, 112(34), 10804-10809. doi:10.1073/pnas.150336211

Network of GRAS transcription factors in plant development, fruit ripening and stress responses

The plant-specific family of GRAS transcription factors has been wide implicated in the regulation of transcriptional reprogramming associated with a diversity of biological functions ranging from plant development processes to stress responses. Functional analyses of GRAS transcription factors supported by in silico structural and comparative analyses are emerging and clarifying the regulatory networks associated with their biological roles. In this review, a detailed analysis of GRAS proteins' structure and biochemical features as revealed by recent discoveries indicated how these characteristics may impact subcellular location, molecular mechanisms, and function. Nomenclature issues associated with GRAS classification into different subfamilies in diverse plant species even in the presence of robust genomic resources are discussed, in particular how it affects assumptions of biological function. Insights into the mechanisms driving evolution of this gene family and how genetic and epigenetic regulation of GRAS contributes to subfunctionalization are provided. Finally, this review debates challenges and future perspectives on the application of this complex but promising gene family for crop improvement to cope with challenges of environmental transition

Plant SWEETs: from sugar transport to plant-pathogen interaction and more unexpected physiological roles

[EN] Sugars Will Eventually be Exported Transporters (SWEETs) have important roles in numerous physiological mechanisms where sugar efflux is critical, including phloem loading, nectar secretion, seed nutrient filling, among other less expected functions. They mediate low affinity and high capacity transport, and in angiosperms this family is composed by 20 paralogs on average. As SWEETs facilitate the efflux of sugars, they are highly susceptible to hijacking by pathogens, making them central players in plant-pathogen interaction. For instance, several species from the Xanthomonas genus are able to upregulate the transcription of SWEET transporters in rice (Oryza sativa), upon the secretion of transcription-activator-like effectors. Other pathogens, such as Botrytis cinerea or Erysiphe necator, are also capable of increasing SWEET expression. However, the opposite behavior has been observed in some cases, as overexpression of the tonoplast AtSWEET2 during Pythium irregulare infection restricted sugar availability to the pathogen, rendering plants more resistant. Therefore, a clear-cut role for SWEET transporters during plant-pathogen interactions has so far been difficult to define, as the metabolic signatures and their regulatory nodes, which decide the susceptibility or resistance responses, remain poorly understood. This fuels the still ongoing scientific question: what roles can SWEETs play during plant-pathogen interaction? Likewise, the roles of SWEET transporters in response to abiotic stresses are little understood. Here, in addition to their relevance in biotic stress, we also provide a small glimpse of SWEETs importance during plant abiotic stress, and briefly debate their importance in the particular case of grapevine (Vitis vinifera) due to its socioeconomic impact.This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT), under the strategic programmes UID/AGR/04033/2020 and UID/BIA/04050/2020. This work was also supported by FCT and European Funds (FEDER/POCI/COMPETE2020) through the research project "MitiVineDrought-Combining `omics' with molecular, biochemical, and physiological analyses as an integrated effort to validate novel and easy-to-implement drought mitigation strategies in grapevine while reducing water use" with ref. PTDC/BIA-FBT/30341/2017 and ref. POCI-01-0145-FEDER-030341, respectively; through the research project "BerryPlastid-Biosynthesis of secondary compounds in the grape berry: unlocking the role of the plastid" with ref. POCI-010145-FEDER-028165 and ref. PTDC/BIA-FBT/28165/2017, respectively; and also through the FCT-funded research project "GrapeInfectomics" (PTDC/ASPHOR/28485/2017). A.C. was supported with a post-doctoral researcher contract/position within the project "MitiVineDrought" (PTDC/BIA-FBT/30341/2017 and POCI-01-0145-FEDER-030341). R.B. was supported by a PhD student grant (PD/BD/113616/2015) under the Doctoral Programme "Agricultural Production Chains-from fork to farm" (PD/00122/2012) funded by FCT. H.B. was supported by a PhD fellowship funded by FCT (SFRH/BD/144638/2019). This work also benefited from the networking activities within the European Unionfunded COST Action CA17111 "INTEGRAPE-Data Integration to maximize the power of omics for grapevine improvement".Breia, R.; Conde, A.; Badim, H.; Fortes, AM.; Geros, H.; Granell Richart, A. (2021). Plant SWEETs: from sugar transport to plant-pathogen interaction and more unexpected physiological roles. Plant Physiology. 186(2):836-852. https://doi.org/10.1093/plphys/kiab127S836852186

Hormone Changes in Tolerant and Susceptible Grapevine Leaves Under Powdery Mildew Infection

The biotrophic fungus Erysiphe necator causes powdery mildew (PM) in grapevine. Phytohormones are major modulators of defensive responses in plants but the analysis of the hormonome associated with grapevine tolerance and susceptibility against this pathogen has not been elucidated. In this study, changes in hormonal profiling were compared between a tolerant (Vitis rupestris × riparia cv. 101-14 Millardet et de Grasset) and a susceptible (Vitis vinifera cv. Aragonêz) species upon E. necator infection. Control and PM-infected leaves were collected at 0, 6, 24, 96 h post-infection (hpi), and analysed through LC-MS/MS. The results showed a distinct constitutive hormonome between tolerant and susceptible species. Constitutive high levels of salicylic acid (SA) and indole-3- acetic acid together with additional fast induction of SA within the first 6 hpi as well as constitutive low levels of jasmonates and abscisic acid may enable a faster and more efficient response towards the PM. The balance among the different phytohormones seems to be species-specific and fundamental in providing tolerance or susceptibility. These insights may be used to develop strategies for conventional breeding and/or editing of genes involved in hormonal metabolism aiming at providing a durable resistance in grapevine against E. necatorinfo:eu-repo/semantics/publishedVersio

The road to molecular identification and detection of fungal grapevine trunk diseases

Grapevine is regarded as a highly profitable culture, being well spread worldwide and mostly directed to the wine-producing industry. Practices to maintain the vineyard in healthy conditions are tenuous and are exacerbated due to abiotic and biotic stresses, where fungal grapevine trunk diseases (GTDs) play a major role. The abolishment of chemical treatments and the intensification of several management practices led to an uprise in GTD outbreaks. Symptomatology of GTDs is very similar among diseases, leading to underdevelopment of the vines and death in extreme scenarios. Disease progression is widely affected by biotic and abiotic factors, and the prevalence of the pathogens varies with country and region. In this review, the state-of-the-art regarding identification and detection of GTDs is vastly analyzed. Methods and protocols used for the identification of GTDs, which are currently rather limited, are highlighted. The main conclusion is the utter need for the development of new technologies to easily and precisely detect the presence of the pathogens related to GTDs, allowing to readily take phytosanitary measures and/or proceed to plant removal in order to establish better vineyard management practices. Moreover, new practices and methods of detection, identification, and quantification of infectious material would allow imposing greater control on nurseries and plant exportation, limiting the movement of infected vines and thus avoiding the propagation of fungal inoculum throughout wine regionsinfo:eu-repo/semantics/publishedVersio

Comparative transcriptomic response of two Pinus species to infection with the pine wood nematode Bursaphelenchus xylophilus

Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, is a serious threat to global forest populations of conifers, in particular Pinus spp. Recently, the presence of PWN was reported in dead Yunnan pine (Pinus yunnanensis) trees under natural conditions. To further understand the potential impact caused by PWN in Yunnan pine populations, a transcriptional profiling analysis was performed over di erent time points (0 hours (h), 6 h, 24 h, 48 h, and 7 days) after PWN inoculation. A total of 9961 di erentially expressed genes were identified after inoculation, which suggested a dynamic response against the pathogen, with a more intense pattern at 48 h after inoculation. The results also highlighted a set of biological mechanisms triggered after inoculation that provide valuable information regarding the response of Yunnan pine to PWN infection. When compared with maritime pine (Pinus pinaster), the Yunnan pine response was less complex and involved a smaller number of di erentially expressed genes, which may be associated with the increased degree of resistance to PWN displayed by Yunnan pine. These results revealed di erent strategies to cope with PWN infection by these two pine species, which display contrasting degrees of susceptibility, especially in the timely perception of the infection and response magnitudeinfo:eu-repo/semantics/publishedVersio

VvSWEET7 Is a Mono- and Disaccharide Transporter Up-Regulated in Response to Botrytis cinerea Infection in Grape Berries

The newly-identified SWEETs are high-capacity, low-affinity sugar transporters with important roles in numerous physiological mechanisms where sugar efflux is critical. SWEETs are desirable targets for manipulation by pathogens and their expression may be transcriptionally reprogrammed during infection. So far, few plant SWEET transporters have been functionally characterized, especially in grapevine. In this study, in the Botrytis-susceptible variety "Trincadeira," we thoroughly analyzed modifications in the gene expression profile of key SWEET genes in Botrytis cinerea-infected grape berries. VvSWEET7 and VvSWEET15 are likely to play an important role during fruit development and Botrytis infection as they are strongly expressed at the green and mature stage, respectively, and were clearly up-regulated in response to infection. Also, B. cinerea infection down-regulated VvSWEET17a expression at the green stage, VvSWEET10 and VvSWEET17d expression at the veraison stage, and VvSWEET11 expression at the mature stage. VvSWEET7 was functionally characterized by heterologous expression in Saccharomyces cerevisiae as a low-affinity, high-capacity glucose and sucrose transporter with a K (m) of 15.42 mM for glucose and a K (m) of 40.08 mM for sucrose. VvSWEET7-GFP and VvSWEET15-GFP fusion proteins were transiently expressed in Nicotiana benthamiana epidermal cells and confocal microscopy allowed to observe that both proteins clearly localize to the plasma membrane. In sum, VvSWEETs transporters are important players in sugar mobilization during grape berry development and their expression is transcriptionally reprogrammed in response to Botrytis infection.The work was supported by National Funds by FCT-Portuguese Foundation for Science and Technology, under the strategic programmes UID/AGR/04033/2019 and UID/BIA/04050/2019. The work was also supported by FCT and European Funds (FEDER/POCI/COMPETE2020) through the research project "MitiVineDrought-Combining "omics" with molecular, biochemical, and physiological analyses as an integrated effort to validate novel and easy-to-implement droughtmitigation strategies in grapevine while reducing water use" with ref. PTDC/BIA-FBT/30341/2017 and ref. POCI-01-0145-FEDER-030341, respectively; through the research project "BerryPlastid-Biosynthesis of secondary compounds in the grape berry: unlocking the role of the plastid" with ref. POCI-01-0145-FEDER-028165 and ref. PTDC/BIA-FBT/28165/2017, respectively; and also through the FCT-funded research project "GrapeInfectomics" (PTDC/ASP-HOR/28485/2017). This work was also supported by the project "INTERACT - VitalityWine -ref. NORTE-01-0145-FEDER-000017 - (through FEDER/COMPETE and NORTE2020/CCDR-N). AC was supported with a post-doctoral fellowof the mentioned INTERACT/VitalityWine project with ref. BPD/UTAD/INTERACT/VW/218/2016 and by a post-doctoral researcher contract/position within the project "MitiVineDrought" (PTDC/BIA-FBT/30341/2017 and POCI-01-0145-FEDER-030341). RB was supported with a PhD student grant (PD/BD/113616/2015) under theDoctoral Programme 'Agricultural Production Chains-from fork to farm' (PD/00122/2012) funded by FCT. This work also benefited from the networking activities within the European Union-funded COST Action CA17111 -"INTEGRAPE-Data Integration to maximize the power of omics for grapevine improvement.

Magnetic resonance breast coils: models and image quality

In three MRI equipments [1,5 T], we evaluated and compared 3 models of dedicated coils to breast MR Imaging. The image quality variable was quantitatively assessed by the indicators: (i) signal-to-noise ratio (SNR) and (ii) uniformity (U). The qualitative assessment by the voluntaries and Radiographers in a Likert scale, considered: (iii) comfort provided during the examination, (iv) accessibility for interventional breast procedures, (v) handling and positioning by Radiographers, (vi) single or bilateral imaging selection, (vii) 17guidance patient within the magnet. Three female volunteers without related breast disease represents the breast patterns of BIRADS system (35, 53 and 72 years old) were exanimate in all coils and underwent a SPIR (spectral inversion recovery) weighted T2 sequence. It was applied a factorial analysis of variance with five fixed factors without replicates to evaluate if there was significant differences between images, concerning the average of SNR and U in the three coils. The differences were significant with the best performance attributed to the coil Z [SNR (p-value=0, F=277,193) e U (p-value=0, F=1487,95)]. There were significant differences in the images quality obtained by the 3 coils (multiple comparisons Tukey test). To the coil z the values are [SNR (15,08u.a.) e U (0,58u.a.)] so, is these coil that produce the best images. The Y coil had lesser rating in image quality variable: (SNR values of 1.89 and U = 0.06). It was found that the draw position of the ROI (Spearman correlation) does not influence the image quality. The highest rating for comfort was given to the coil X followed by coil Z. The coil model choice is important to perform high quality images, patient comfort and handling in positioning. The study results can contribute to a reduction in financial speculation linked to the commercial approaches of competing manufacturers on the market

A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing

Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe