Characterization of FchAGL9 and FchSHP, two MADS-boxes related to softening of Fragaria chiloensis fruit.

Fragaria chiloensis is a Chilean native species that softens intensively during its ripening. Its softening is related to cell wall disassembly due to the participation of cell wall degrading enzymes. Softening of F. chiloensis fruit can be accelerated by ABA treatment which is accompanied by the increment in the expression of key cell wall degrading genes, however the molecular machinery involved in the transcriptional regulation has not been studied until now. Therefore, the participation of two MADS-box transcription factors belonging to different subfamilies, FchAGL9 and FchSHP, was addressed. Both TFs are members of type-II MADS-box family (MIKC-type) and localized in the nucleus. FchAGL9 and FchSHP are expressed only in flower and fruit tissues, rising as the fruit softens with the highest expression level at C3-C4 stages. EMSA assays demonstrated that FchAGL9 binds to CArG sequences of RIN and SQM, meanwhile FchSHP interacts only with RIN. Bimolecular fluorescence complementation and yeast two-hybrid assays confirmed FchAGL9-FchAGL9 and FchAGL9-FchSHP interactions. Hetero-dimer structure was built through homology modeling concluding that FchSHP monomer binds to DNA. Functional validation by Luciferase-dual assays indicated that FchAGL9 transactivates FchRGL and FchPG's promoters, meanwhile FchSHP transactivates those of FchEXP2, FchRGL and FchPG. Over-expression of FchAGL9 in C2 F. chiloensis fruit rises FchEXP2 and FchEXP5 transcripts, meanwhile the over-expression of FchSHP also increments FchXTH1 and FchPL; in both cases there is a down-regulation of FchRGL and FchPG. In summary, we provided evidence of FchAGL9 and FchSHP participating in the transcription regulation associated to F. chiloensis's softening.

Involvement of the GH38 Family Exoglycosidase α-Mannosidase in Strawberry Fruit Ripening.

Exoglycosidase enzymes hydrolyze the N-glycosylations of cell wall enzymes, releasing N-glycans that act as signal molecules and promote fruit ripening. Vesicular exoglycosidase α-mannosidase enzymes of the GH38 family (EC 3.2.1.24; α-man) hydrolyze N-glycans in non-reduced termini. Strawberry fruit (Fragaria × ananassa) is characterized by rapid softening as a result of cell wall modifications during the fruit ripening process. Enzymes acting on cell wall polysaccharides explain the changes in fruit firmness, but α-man has not yet been described in F. × ananassa, meaning that the indirect effects of N-glycan removal on its fruit ripening process are unknown. The present study identified 10 GH38 α-man sequences in the F. × ananassa genome with characteristic conserved domains and key residues. A phylogenetic tree built with the neighbor-joining method and three groups of α-man established, of which group I was classified into three subgroups and group III contained only Poaceae spp. sequences. The real-time qPCR results demonstrated that FaMAN genes decreased during fruit ripening, a trend mirrored by the total enzyme activity from the white to ripe stages. The analysis of the promoter regions of these FaMAN genes was enriched with ripening and phytohormone response elements, and contained cis-regulatory elements related to stress responses to low temperature, drought, defense, and salt stress. This study discusses the relevance of α-man in fruit ripening and how it can be a useful target to prolong fruit shelf life.

YABBY transcription factor family in the octoploid Fragaria × ananassa and five diploid Fragaria species.

YABBY genes encode specific TFs of seed plants involved in development and formation of leaves, flowers, and fruit. In the present work, genome-wide and expression analyses of the YABBY gene family were performed in six species of the Fragaria genus: Fragaria × ananassa, F. daltoniana, F. nilgerrensis, F. pentaphylla, F. viridis, and F. vesca. The chromosomal location, synteny pattern, gene structure, and phylogenetic analyses were carried out. By combining RNA-seq data and RT-qPCR analysis we explored specific expression of YABBYs in F. × ananassa and F. vesca. We also analysed the promoter regions of FaYABBYs and performed MeJA application to F. × ananassa fruit to observe effects on gene expression. We identified and characterized 25 YABBY genes in F. × ananassa and six in each of the other five species, which belong to FIL/YAB3 (YABBY1), YAB2 (YABBY2), YAB5 (YABBY5), CRC, and INO clades previously described. Division of the YABBY1 clade into YABBY1.1 and YABBY1.2 subclades is reported. We observed differential expression according to tissue, where some FaYABBYs are expressed mainly in leaves and flowers and to a minor extent during fruit development of F. × ananassa. Specifically, the FaINO genes contain jasmonate-responsive cis-acting elements in their promoters which may be functional since FaINOs are upregulated in F. × ananassa fruit under MeJA treatment. This study suggests that YABBY TFs play an important role in the development- and environment-associated responses of the Fragaria genus.

Unraveling the key step in the aroma puzzle: Insights into alcohol acyltransferases in strawberries.

Alcohol acyltransferases (AATs) play a crucial role in catalyzing the transfer of acyl groups, contributing to the diverse aroma of fruits, including strawberries. In this research we identified nine AAT genes in strawberries through a comprehensive analysis involving phylogenetics, gene structure, conserved motifs, and structural protein model examinations. The study used the 'Camarosa' strawberry genome database, and experiments were conducted with fruits harvested at different developmental and ripening stages. The transcriptional analysis revealed differential expression patterns among the AAT genes during fruit ripening, with only four genes (SAAT, FaAAT2, FaAAT7, and FaAAT9) showing increased transcript accumulation correlated with total AAT enzyme activity. Additionally, the study employed in silico methods, including sequence alignment, phylogenetic analysis, and structural modeling, to gain insights into the AAT protein model structures with increase expression pattern during fruit ripening. The four modeled AAT proteins exhibited structural similarities, including conserved catalytic sites and solvent channels. Furthermore, the research investigated the interaction of AAT proteins with different substrates, highlighting the enzymes' promiscuity in substrate preferences. The study contributes with valuable information to unveil AAT gene family members in strawberries, providing scientific background for further exploration of their biological characteristics and their role in aroma biosynthesis during fruit ripening.

Structural and transcriptional characterization of pyruvate decarboxylase (PDC) gene family during strawberry fruit ripening process.

Strawberry is one of the most popular fruits in the world, because their high fruit quality, especially with respect to the combination of aroma, flavor, color, and nutritional compounds. Pyruvate decarboxylase (PDC) is the first of two enzymes specifically required for ethanolic fermentation and catalyzes the decarboxylation of pyruvate to yield acetaldehyde and CO2. The ethanol, an important alcohol which acts as a precursor for the ester and other alcohols formation in strawberry, is produced by the PDC. The objective was found all different PDCs genes present in the strawberry genome and investigate PDC gene expression and ligand-protein interactions in strawberry fruit. Volatile organic compounds were evaluated during the development of the fruit. After this, eight FaPDC were identified with four genes that increase the relative expression during fruit ripening process. Molecular dynamics simulations were performed to analyze the behavior of Pyr and TPP ligands within the catalytic and regulatory sites of the PDC proteins. Results indicated that energy-restrained simulations exhibited minor fluctuations in ligand-protein interactions, while unrestrained simulations revealed crucial insights into ligand affinity. TPP consistently displayed strong interactions with the catalytic site, emphasizing its pivotal role in enzymatic activity. However, FaPDC6 and FaPDC9 exhibited decreased pyruvate affinity initially, suggesting unique binding characteristics requiring further investigation. Finally, the present study contributes significantly to understanding PDC gene expression and the intricate molecular dynamics underlying strawberry fruit ripening, shedding light on potential targets for further research in this critical biological pathway.

PIPs from Fragaria vesca: A structural analysis of native and mutated protein.

Aquaporins are an ancient family of membrane channel proteins present in all eukaryotes and most prokaryotes, and apart from water, allow the transport of neutral solutes and organic compounds through the pore. These proteins are essential role differentially expressed during ripening in Fragaria vesca fruits. Fv PIP2-1a is intensively expressed in fruits, inclusive several other proteins member are differentially expressed in fruit but also in other plant tissues. Phylogenetic analysis shows that Fv PIP2-1a grouped with other Fragaria proteins and far apart from other F. vesca PIP proteins. A structural model for Fv PIP2-1a protein was built by comparative modelling methodology, which was validated and refined by molecular dynamics simulation. Fv PIP2-1a structure consists of 6 transmembrane regions and two NPA domains. The mobilization of water was analyzed by molecular docking simulations in wildtype and two mutants. Interestingly, the mutant FvPIP2-1a_H214G allowed the prediction of an increment in the flux of water molecules. On contrary, structural analysis predicted that H214E mutation blocked passage of water associated to constriction of the pore.

Multivariate analysis methods improve the selection of strawberry genotypes with low cold requirement.

Methods of multivariate analysis is a powerful approach to assist the initial stages of crops genetic improvement, particularly, because it allows many traits to be evaluated simultaneously. In this study, heat-tolerant genotypes have been selected by analyzing phenotypic diversity, direct and indirect relationships among traits were identified, and four selection indices compared. Diversity was estimated using K-means clustering with the number of clusters determined by the Elbow method, and the relationship among traits was quantified by path analysis. Parametric and non-parametric indices were applied to selected genotypes using the magnitude of genotypic variance, heritability, genotypic coefficient of variance, and assigned economic weight as selection criteria. The variability among materials led to the formation of two non-overlapping clusters containing 40 and 154 genotypes. Strong to moderate correlations were found between traits with direct effect of the number of commercial fruit on the mass of commercial fruit. The Smith and Hazel index showed the greatest total gains for all criteria; however, concerning the biochemical traits, the Mulamba and Mock index showed the highest magnitudes of predicted gains. Overall, the K-means clustering, correlation analysis, and path analysis complement the use of selection indices, allowing for selection of genotypes with better balance among the assessed traits.

Productivity of strawberry genotypes in the south and southwest mesoregion of Minas Gerais / Produtividade de genótipos de morangueiro na mesoregião sul e sudoeste de Minas Gerais

The strawberry is a perennial plant of temperate climate belonging to the Rosaceae family, much appreciated for presenting a fleshy and succulent receptacle as an edible part. Among small fruits, in Brazil it represents the species of greatest economic expression. The breeding of the strawberry aims to meet the demands of the market, mainly regarding the quality of the fruit required by consumers. Thus, the selection of genotypes that have good quality, productivity and adaptation is extremely important for the development of culture in the country, as well as for making seedlings available at lower prices. The objective of this work was to evaluate the agronomic performance and productivity of experimental strawberry genotypes in the city of Alfenas, Minas Gerais. For this, the experiment was carried out in the premises of the José do Rosário Vellano University (UNIFENAS), Alfenas-MG, in an experimental area of the Olericulture and Experimentation Sector (21025'45''S, 45056'50 "W, 880 m altitude). The experimental design used was completely randomized, with eleven treatments, distributed in seven experimental genotypes, namely MDA01, MDA06, MCA 119, MFA444, MDA19, MDA11 and MDA23, and four commercial cultivars taken as control, being them Pircinque, Albion, Aromas and Festival, in eight repetitions. The following characteristics were evaluated total production per plant (grams of strawberries per plant-1), average weight of fruits per plant (grams/fruit-1), total number of fruits per plant and number of stolons (seedlings) per plant. The experimental genotypes that showed the highest total productivity and average fruit weight were MDA01, MDA23 and MDA19. These materials are presented as promising for the strawberry breeding program in the region and should be reevaluated under other edaphoclimatic conditions and/or used as parents in new crossings for the next stages of the program.

O morangueiro é uma planta perene de clima temperado pertencente à família das Rosáceas, muito apreciado por apresentar um receptáculo carnoso e suculento como parte comestível. Entre os frutos pequenos, no Brasil representa a espécie de maior expressão econômica. O melhoramento genético do morangueiro visa atender às demandas do mercado, principalmente, quanto ao quesito qualidade do fruto exigido pelos consumidores. Dessa forma, a seleção de genótipos que apresentem boa qualidade, produtividade e adaptação, é de extrema importância para o desenvolvimento da cultura no país, bem como para a disponibilização de mudas com menores preços. Objetivou-se com este trabalho avaliar o desempenho agronômico e a produtividade de genótipos experimentais de morangueiro no município de Alfenas, Minas Gerais. O experimento foi conduzido nas dependências da Universidade José do Rosário Vellano (UNIFENAS), em área experimental do Setor de Olericultura e Experimentação. O delineamento experimental utilizado foi inteiramente casualizado, com onze tratamentos, distribuídos em sete genótipos experimentais provenientes do banco de germoplasma da Universidade Federal de Lavras, sendo eles MDA01, MDA06, MCA 119, MFA444, MDA19, MDA11 e MDA23, e quatro cultivares comerciais tidas como controle, sendo elas Pircinque, Albion, Aromas e Festival, em oito repetições. Foram avaliadas as seguintes características: produção total por planta (gramas de morangos por planta), peso médio de frutos por planta (gramas/fruto), número total de frutos por planta e quantidade de estolões emitidos (mudas) por planta. Os genótipos experimentais que apresentaram os maiores índices de produtividade total e peso médio dos frutos foram MDA01, MDA23 e MDA19. Estes materiais se apresentam como promissores para o programa de melhoramento genético do morangueiro na região e devem ser reavaliados em outras condições edafoclimáticas e/ou utilizados como genitores em novos cruzamentos para as próximas etapas do programa.

Seasonal Variation of Plant Defense Inductor Ellagitannins in Strawberry Leaves under Field Conditions for Phytosanitary Technological Applications.

Many natural compounds can activate the plant immunity, and for this reason, they have attracted special interest in crop disease management. Previously, we isolated from strawberry leaves an ellagitannin (HeT), which elicits plant defense responses. In this research, we investigated bioactive compounds from field-collected strawberry leaves capable of inducing defense responses in Arabidopsis thaliana against a bacterial pathogen. Methanolic extracts of strawberry leaves sampled at different months were obtained and compared. The highest content of total soluble phenolic compounds was found in the methanolic extracts of leaves sampled in December (DME). The defense response induced in A. thaliana by DME was attributed to two ellagitannins, the HeT and galloyl-HHDP-glucose. Both compounds exhibited phytoprotective effects against Pseudomonas viridiflava and induced the expression of PDF1.2 and PR1 genes. These results provide an economic value to strawberry leaves, normally discarded at the end of the harvest stage of the crop, as a raw material for plant health enhancer bioinputs.

Effect of Exogenous Auxin Treatment on Cell Wall Polymers of Strawberry Fruit.

The role of auxin in the fruit-ripening process during the early developmental stages of commercial strawberry fruits (Fragaria x ananassa) has been previously described, with auxin production occurring in achenes and moving to the receptacle. Additionally, fruit softening is a consequence of the depolymerization and solubilization of cell wall components produced by the action of a group of proteins and enzymes. The aim of this study was to compare the effect of exogenous auxin treatment on the physiological properties of the cell wall-associated polysaccharide contents of strawberry fruits. We combined thermogravimetric (TG) analysis with analyses of the mRNA abundance, enzymatic activity, and physiological characteristics related to the cell wall. The samples did not show a change in fruit firmness at 48 h post-treatment; by contrast, we showed changes in the cell wall stability based on TG and differential thermogravimetric (DTG) analysis curves. Less degradation of the cell wall polymers was observed after auxin treatment at 48 h post-treatment. The results of our study indicate that auxin treatment delays the cell wall disassembly process in strawberries.

Expression profiling of endo-xylanases during ripening of strawberry cultivars with contrasting softening rates. Influence of postharvest and hormonal treatments.

BACKGROUND: Softening is one of the main features that determine fruit quality during strawberry (Fragaria x ananassa, Duch.) ripening and storage. Being closely related to textural changes, the molecular and biochemical bases underlying strawberry cell-wall metabolism is a matter of interest. Here we investigated the abundance of transcripts encoding putative strawberry endo-xylanases in plant tissues, during fruit ripening and under postharvest and hormonal treatments. Total xylanase activity and expression of related genes in strawberry varieties with contrasting firmness were analyzed. RESULTS: FaXynA and FaXynC mRNA abundance was significantly higher than FaXynB in each plant tissue studied. Higher total xylanase activity was detected at the end of the ripening of the softer cultivar ('Toyonoka') in comparison with the firmer one ('Camarosa'), correlating with the abundance of FaXynA and FaXynC transcripts. Postharvest 1-methylcyclopropene treatment up-regulated FaXynA and FaXynC expressions. FaXynC mRNA abundance decreased with heat treatment but the opposite was observed for FaXynA. Calcium chloride treatment down-regulated FaXynA and FaXynC expression. Both genes responded differently to plant growth regulators' exposure. FaXynC expression was down-regulated by auxins and gibberellins treatment and up-regulated by abscisic acid. FaXynA was up-regulated by auxins, while no changes in mRNA levels were evident by abscisic acid and gibberellins treatment. Ethephon exposure did not change FaXynA and FaXynC expressions. CONCLUSION: New knowledge about the presence of xylanases in ripening strawberry fruit and their response to postharvest and hormonal treatments is provided. Our findings suggest a role for endo-xylanases in hemicelluloses depolymerization and possibly in strawberry fruit softening. © 2020 Society of Chemical Industry.

Agronomic performance of new strawberry cultivars in southern Brazil / Desempenho agronômico de novos cultivares de morango no sul do Brasil

The choice of cultivars to be used by strawberry farmers is essential since it could determine the success of the crop. The present study aimed to evaluate the productive and qualitative performance of strawberry genotypes grown in Vacaria, RS, Brazil. Twelve strawberry genotypes were compared, constituting the different treatments: cultivars Strawberry Festival, Oso Grande, Jonica, and Pircinque, and selections FRF PA3, FRF CE 51, FRF CE 56, FRF PIR 29, FRF PIR 54, FRF 85.04, FRF 149.18, and FRF 102.21. The seedlings were transplanted on May 13, 2014, in a semi-hydroponic cultivation system, adopting a randomized block design with four blocks and an experimental unit of ten useful plants. The variables evaluated were the number of fruits, total production per plant, productivity, commercial productivity, fresh fruit mass, commercial percentage, soluble solids, titratable acidity, soluble solids to total acidity ratio, pulp firmness, and production seasonality. The mean values were subjected to an analysis of variance and multivariate analysis, and their means were compared by the Scott-Knott test at a 5% error probability.Cultivar Strawberry Festival and selection FRF 102.21 showed higher productions (1138 g plant-1 nd 1019 g plant-1, respectively) and quantities of fruits produced (85 un plant-1 and 87 un plant-1, respectively). Cultivar Jonica and selection FRF 85.4 showed higher percentages of marketable fruits. The Pircinque cultivar was prominent for sugar content, presenting a value 24% superior to the general average of the cultivars. Cultivars Strawberry Festival, Jonica, and Pircinque and selection FRF 102.21 showed the highest qualitative and quantitative gains for the region of Vacaria, RS, Brazil.

A escolha dos cultivares a serem utilizadas pelos produtores de morangos é fundamental, pois pode determinar o sucesso da cultura. O presente estudo tem como objetivo avaliar o desempenho produtivo e qualitativo de genótipos de morangueiro cultivados em Vacaria, RS, Brasil. Foram comparados 12 genótipos de morangueiro, constituindo os diferentes tratamentos: cultivares Strawberry Festival, Oso Grande, Jonica e Pircinque, e seleções FRF PA3, FRF CE 51, FRF CE 56, FRF PIR 29, FRF PIR 54, FRF 85,04, FRF 149,18, e FRF 102,21. As mudas foram transplantadas em 13 de maio de 2014, em sistema de cultivo semi-hidropônico, adotando-se o delineamento em blocos casualizados, com quatro blocos e unidade experimental de dez plantas úteis. As variáveis avaliadas foram número de frutos, produção total por planta, produtividade, produtividade comercial, massa fresca do fruto, porcentagem comercial, sólidos solúveis, acidez titulável, relação (sólidos solúveis/acidez total), firmeza da polpa e a sazonalidade da produção. Os valores médios foram submetidos à análise de variância e análise multivariada, e suas médias comparadas pelo teste de Scott-Knott a 5% de probabilidade de erro. O cultivar Strawberry Festival e seleção FRF 102,21 apresentaram maior produção (1138 e 1019 g planta-1) e quantidade de frutos produzidos (85 e 87 un planta-1). A cultivar Jonica e a seleção FRF 85,4 apresentaram maior porcentagem de frutos comerciáveis. O cultivar Pircinque se destacou-se pelo seu teor de açúcares, apresentando um valor 24% superior à média geral dos cultivares. As cultivares Strawberry Festival, Jonica e Pircinque e seleção FRF 102,21 apresentaram os maiores ganhos qualitativos e quantitativos para a região de Vacaria, RS.

Agronomic performance of new strawberry cultivars in southern Brazil / Desempenho agronômico de novos cultivares de morango no sul do Brasil

The choice of cultivars to be used by strawberry farmers is essential since it could determine the success of the crop. The present study aimed to evaluate the productive and qualitative performance of strawberry genotypes grown in Vacaria, RS, Brazil. Twelve strawberry genotypes were compared, constituting the different treatments: cultivars Strawberry Festival, Oso Grande, Jonica, and Pircinque, and selections FRF PA3, FRF CE 51, FRF CE 56, FRF PIR 29, FRF PIR 54, FRF 85.04, FRF 149.18, and FRF 102.21. The seedlings were transplanted on May 13, 2014, in a semi-hydroponic cultivation system, adopting a randomized block design with four blocks and an experimental unit of ten useful plants. The variables evaluated were the number of fruits, total production per plant, productivity, commercial productivity, fresh fruit mass, commercial percentage, soluble solids, titratable acidity, soluble solids to total acidity ratio, pulp firmness, and production seasonality. The mean values were subjected to an analysis of variance and multivariate analysis, and their means were compared by the Scott-Knott test at a 5% error probability.Cultivar Strawberry Festival and selection FRF 102.21 showed higher productions (1138 g plant-1 nd 1019 g plant-1, respectively) and quantities of fruits produced (85 un plant-1 and 87 un plant-1, respectively). Cultivar Jonica and selection FRF 85.4 showed higher percentages of marketable fruits. The Pircinque cultivar was prominent for sugar content, presenting a value 24% superior to the general average of the cultivars. Cultivars Strawberry Festival, Jonica, and Pircinque and selection FRF 102.21 showed the highest qualitative and quantitative gains for the region of Vacaria, RS, Brazil.(AU)

A escolha dos cultivares a serem utilizadas pelos produtores de morangos é fundamental, pois pode determinar o sucesso da cultura. O presente estudo tem como objetivo avaliar o desempenho produtivo e qualitativo de genótipos de morangueiro cultivados em Vacaria, RS, Brasil. Foram comparados 12 genótipos de morangueiro, constituindo os diferentes tratamentos: cultivares Strawberry Festival, Oso Grande, Jonica e Pircinque, e seleções FRF PA3, FRF CE 51, FRF CE 56, FRF PIR 29, FRF PIR 54, FRF 85,04, FRF 149,18, e FRF 102,21. As mudas foram transplantadas em 13 de maio de 2014, em sistema de cultivo semi-hidropônico, adotando-se o delineamento em blocos casualizados, com quatro blocos e unidade experimental de dez plantas úteis. As variáveis avaliadas foram número de frutos, produção total por planta, produtividade, produtividade comercial, massa fresca do fruto, porcentagem comercial, sólidos solúveis, acidez titulável, relação (sólidos solúveis/acidez total), firmeza da polpa e a sazonalidade da produção. Os valores médios foram submetidos à análise de variância e análise multivariada, e suas médias comparadas pelo teste de Scott-Knott a 5% de probabilidade de erro. O cultivar Strawberry Festival e seleção FRF 102,21 apresentaram maior produção (1138 e 1019 g planta-1) e quantidade de frutos produzidos (85 e 87 un planta-1). A cultivar Jonica e a seleção FRF 85,4 apresentaram maior porcentagem de frutos comerciáveis. O cultivar Pircinque se destacou-se pelo seu teor de açúcares, apresentando um valor 24% superior à média geral dos cultivares. As cultivares Strawberry Festival, Jonica e Pircinque e seleção FRF 102,21 apresentaram os maiores ganhos qualitativos e quantitativos para a região de Vacaria, RS.(AU)

Genome-wide identification, and characterization of the CDPK gene family reveal their involvement in abiotic stress response in Fragaria x ananassa.

Calcium-dependent protein kinases (CDPKs) are encoded by a large gene family and play important roles against biotic and abiotic stresses and in plant growth and development. To date, little is known about the CDPK genes in strawberry (Fragaria x ananassa). In this study, analysis of Fragaria x ananassa CDPK gene family was performed, including gene structures, phylogeny, interactome and expression profiles. Nine new CDPK genes in Fragaria x ananassa were identified based on RNA-seq data. These identified strawberry FaCDPK genes were classified into four main groups, based on the phylogenetic analysis and structural features. FaCDPK genes were differentially expressed during fruit development and ripening, as well as in response to abiotic stress (salt and drought), and hormone (abscisic acid) treatment. In addition, the interaction network analysis pointed out proteins involved in the ABA-dependent response to plant stress via Ca2+ signaling, especially RBOHs. To our knowledge, this is the first report on CDPK families in Fragaria x ananassa, and it will provide valuable information for development of biofortified fruits and stress tolerant plants.

A new functional JAZ degron sequence in strawberry JAZ1 revealed by structural and interaction studies on the COI1-JA-Ile/COR-JAZs complexes.

The phytohormone jasmonoyl-isoleucine (JA-Ile) regulates fundamental plant processes as developmental and defense responses. JA-Ile mediates the interaction between the F-box protein COI1 (part of the SCFCOI1 E3 ubiquitin ligase) and a JAZ repressor leading to early jasmonate responses. The Arabidopsis JAZ1 protein contains the canonical LPIARR degron sequence, which is responsible for the stabilization of the AtCOI1-JA-Ile-AtJAZ1 complex. In strawberry (Fragaria × ananassa) JAZ family was described at the transcriptional level during fruit development but the information about the interaction mode of this complex is still scarce at the molecular level. To gain insight into the strawberry JA-Ile receptor complex, we evaluated the interaction at the structural level, and protein models were built and analyzed for FaCOI1 and FaJAZ1, FaJAZ8.1, and FaJAZ10. The interaction between FaCOI1 and FaJAZ1, FaJAZ8.1 and FaJAZ10 were explored using several ligands, through molecular docking and molecular dynamics (MD) simulations, finding the strongest interaction with (+)-7-iso-JA-Ile than other ligands. Additionally, we tested interactions between FaCOI1 and FaJAZs by yeast two-hybrid assays in the presence of coronatine (COR, a JA-Ile mimic). We detected strong COR-dependent interactions between FaCOI1 and FaJAZ1. Interestingly, FaJAZ1 contains a new non-canonical (IPMQRK) functional degron sequence, in which Arg and Lys are the key residues for maintaining the interaction of the FaCOI1-COR-FaJAZ1 complex as we observed in mutated versions of the FaJAZ1 degron. Phylogenetic analysis showed that the IPMQRK degron is only present in orthologs belonging to the Rosoideae but not in other Rosaceae subfamilies. Together, this study uncovers a new degron sequence in plants, which could be required to make an alternative and functional JA-Ile perception complex in strawberry.

Characterization of FcXTH2, a Novel Xyloglucan Endotransglycosylase/Hydrolase Enzyme of Chilean Strawberry with Hydrolase Activity.

Xyloglucan endotransglycosylase/hydrolases (XTHs) are cell wall enzymes with hydrolase (XEH) and/or endotransglycosylase (XET) activities. As they are involved in the modification of the xyloglucans, a type of hemicellulose present in the cell wall, they are believed to be very important in different processes, including growth, development, and fruit ripening. Previous studies suggest that XTHs might play a key role in development and ripening of Fragaria chiloensis fruit, and its characterization is pending. Therefore, in order to provide a biochemical characterization of the FcXTH2 enzyme to explain its possible role in strawberry development, the molecular cloning and the heterologous expression of FcXTH2 were performed. The recombinant FcXTH2 was active and displayed mainly XEH activity. The optimal pH and temperature are 5.5 and 37 °C, respectively. A KM value of 0.029 mg mL-1 was determined. Additionally, its protein structural model was built through comparative modeling methodology. The model showed a typically ß-jelly-roll type folding in which the catalytic motif was oriented towards the FcXTH2 central cavity. Using molecular docking, protein-ligand interactions were explored, finding better interaction with xyloglucan than with cellulose. The data provided groundwork for understanding, at a molecular level, the enzymatic mechanism of FcXTH2, an important enzyme acting during the development of the Chilean strawberry.

Productive and qualitative characteristics of strawberry genotypes in the Plateau of the State of Santa Catarina, Brazil / Características produtivas e qualitativas de genótipos de morangueiro no Planalto Catarinense

To produce strawberries on a commercial scale, it is necessary to choose the cultivars best adapted to the growing site. This work aimed to compare strawberry genotypes regarding production and fruit quality, in the municipality of Lages, State of Santa Catarina, Brazil, during the 2017/2018 harvest season. In this work, 15 genotypes were evaluated, five commercial cultivars and ten advanced selections. The experimental design was in randomized blocks, with four replicates and plots of 11 plants. The cultivation system used was in the soil of an open field, in beds of approximately 90 centimeters, with three rows per bed. Planting distance was of 30 centimeters between rows and plants. The Sabrina cultivar showed the highest production (1,231.77 g plant-1) and number of fruits (78.48 fruits plant-1). The highest quality fruits were obtained from the selections FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 and cultivar Pircinque, characterized by soluble solids/titratable acidity ratios above 15. In the productive cycle in question, cultivar Sabrina presented the best performance, demonstrating the potential for recommendation to the producers of the South Plateau of State of Santa Catarina.

Para produzir morangos em escala comercial, é necessário escolher as cultivares melhor adaptadas ao local de cultivo. Objetivou-se com este trabalho confrontar genótipos de morangueiro quanto a aspectos de produção e qualidade de frutos, no município de Lages, em Santa Catarina, no ciclo agrícola 2017/2018. Foram avaliados 15 genótipos, sendo cinco cultivares comerciais e dez seleções avançadas. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e parcelas constituídas por 11 plantas. O sistema de cultivo utilizado foi no solo, em campo aberto, em canteiros com aproximadamente 90 centímetros de largura, com três linhas de plantio por canteiro. A distância de plantio foi de 30 centímetros, entre fileiras e plantas. A cultivar Sabrina obteve a maior produção (1.231,77 g planta-1) e número de frutos (78,48 frutos planta-1). Com as seleções FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 e a cultivar Pircinque se obtiveram os frutos de qualidade superior, caracterizados por médias acima de 15 para a relação sólidos solúveis / acidez titulável. No ciclo produtivo em questão, a cultivar Sabrina apresentou o melhor desempenho, demonstrando potencial para ser recomendada aos produtores da região do Planalto Sul Catarinense.

Productive and qualitative characteristics of strawberry genotypes in the Plateau of the State of Santa Catarina, Brazil / Características produtivas e qualitativas de genótipos de morangueiro no Planalto Catarinense

To produce strawberries on a commercial scale, it is necessary to choose the cultivars best adapted to the growing site. This work aimed to compare strawberry genotypes regarding production and fruit quality, in the municipality of Lages, State of Santa Catarina, Brazil, during the 2017/2018 harvest season. In this work, 15 genotypes were evaluated, five commercial cultivars and ten advanced selections. The experimental design was in randomized blocks, with four replicates and plots of 11 plants. The cultivation system used was in the soil of an open field, in beds of approximately 90 centimeters, with three rows per bed. Planting distance was of 30 centimeters between rows and plants. The Sabrina cultivar showed the highest production (1,231.77 g plant-1) and number of fruits (78.48 fruits plant-1). The highest quality fruits were obtained from the selections FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 and cultivar Pircinque, characterized by soluble solids/titratable acidity ratios above 15. In the productive cycle in question, cultivar Sabrina presented the best performance, demonstrating the potential for recommendation to the producers of the South Plateau of State of Santa Catarina.(AU)

Para produzir morangos em escala comercial, é necessário escolher as cultivares melhor adaptadas ao local de cultivo. Objetivou-se com este trabalho confrontar genótipos de morangueiro quanto a aspectos de produção e qualidade de frutos, no município de Lages, em Santa Catarina, no ciclo agrícola 2017/2018. Foram avaliados 15 genótipos, sendo cinco cultivares comerciais e dez seleções avançadas. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e parcelas constituídas por 11 plantas. O sistema de cultivo utilizado foi no solo, em campo aberto, em canteiros com aproximadamente 90 centímetros de largura, com três linhas de plantio por canteiro. A distância de plantio foi de 30 centímetros, entre fileiras e plantas. A cultivar Sabrina obteve a maior produção (1.231,77 g planta-1) e número de frutos (78,48 frutos planta-1). Com as seleções FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 e a cultivar Pircinque se obtiveram os frutos de qualidade superior, caracterizados por médias acima de 15 para a relação sólidos solúveis / acidez titulável. No ciclo produtivo em questão, a cultivar Sabrina apresentou o melhor desempenho, demonstrando potencial para ser recomendada aos produtores da região do Planalto Sul Catarinense.(AU)

Colletotrichum acutatum M11 can suppress the defence response in strawberry plants.

MAIN CONCLUSION: Colletotrichum acutatum M11 produces a diffusible compound that suppresses the biochemical, physiological, molecular and anatomical events associated with the defence response induced by the plant defence elicitor AsES. The fungal pathogen Colletotrichum acutatum, the causal agent of anthracnose disease, causes important economical losses in strawberry crop worldwide and synthetic agrochemicals are used to control it. In this context, the control of the disease using bioproducts is gaining reputation as an alternative of those toxic and pollutant agrochemicals. However, the success of the strategies using bioproducts can be seriously jeopardized in the presence of biological agents exerting a defence suppression effect. In this report, we show that the response defence induced in plant by the elicitor AsES from the fungus Acremonium strictum can be suppressed by a diffusible compound produced by isolate M11 of C. acutatum. Results revealed that strawberry plants treated with conidia of the isolated M11 or the culture supernatant of the isolate M11 suppress: ROS accumulation (e.g., H2O2, O2·- and NO), cell wall reinforcement (e.g., lignin and callose), and the up-regulation of defence-related genes (e.g., FaPR1, FaCHI23, FaPDF1.2, FaCAT, FaCDPK, FaCML39) induced by the elicitor AsES. Additionally, we show that the defence suppressing effect causes a systemic sensitization of plants. Results presented here highlights the necessity to make an integral study of the microbiome present in soils and plant biosphere before applying defence activation bioproducts to control crop diseases.