Constitutive Defense Research Articles

A Comparative Analysis of Constitutional Rights in the Gambia and Indonesia

While there is strong advocacy globally on human rights, little attention is paid to constitutional rights in some countries. Many constitutions contain constitutional rights, which are mainly referred to as the bill of rights in their constitutions. This piece presents a comparative exposition of the constitutional rights in The Gambia and Indonesia as constitutional states. Both countries are sovereign, and the strength and lethargy in enforcing these rights in these countries are of great significance in this research. In this research, empirical and normative research approaches are taken to examine both primary and secondary data. Primary materials like the constitutions of the two countries, legislation and court cases on constitutional rights are used. Secondary materials like articles and books are sufficiently used to support this research. Cognizant that a constitution is both a legal and political instrument, the Constitutional Court of Indonesia is undermined to a certain extent by both the House of Representatives and the Executive, and The Gambia’s sparing moments in disobeying High Court orders as regards constitutional rights, this research finally reaches an informed verdict that constitutional rights are different from human rights and approaches to their enhancement ought to be premised on citizenship. The inclusion of legal provisions in constitutions does not, ex cathedra, make institutions strong. Therefore, both countries need a paradigm shift in their national mechanisms to strengthen the institutions that enforce these rights despite the institutional differences in socio-political and socio-legal structures. To do this, the constitutional defense bodies must be comparatively autonomous from other institutions exercising the legislative, executive, and judicial functions to carry out such activities to increase individuals’ and States’ respect for the constitutions and the law and the constitutional rights guaranteed by these constitutions will make fresh and significant strides.

Differential defensive and nutritional traits among cultivated tomato and its wild relatives shape their interactions with a specialist herbivore.

Cultivated tomato presented lower constitutive volatiles, reduced morphological and chemical defenses, and increased leaf nutritional quality that affect its resistance against the specialist herbivore Tuta absoluta compared to its wild relatives. Plant domestication process has selected desirable agronomic attributes that can both intentionally and unintentionally compromise other important traits, such as plant defense and nutritional value. However, the effect of domestication on defensive and nutritional traits of plant organs not exposed to selection and the consequent interactions with specialist herbivores are only partly known. Here, we hypothesized that the modern cultivated tomato has reduced levels of constitutive defense and increased levels of nutritional value compared with its wild relatives, and such differences affect the preference and performance of the South American tomato pinworm, Tuta absoluta-an insect pest that co-evolved with tomato. To test this hypothesis, we compared plant volatile emissions, leaf defensive (glandular and non-glandular trichome density, and total phenolic content), and nutritional traits (nitrogen content) among the cultivated tomato Solanum lycopersicum and its wild relatives S. pennellii and S. habrochaites. We also determined the attraction and ovipositional preference of female moths and larval performance on cultivated and wild tomatoes. Volatile emissions were qualitatively and quantitatively different among the cultivated and wild species. Glandular trichomes density and total phenolics were lower in S. lycopersicum. In contrast, this species had a greater non-glandular trichome density and leaf nitrogen content. Female moths were more attracted and consistently laid more eggs on the cultivated S. lycopersicum. Larvae fed on S. lycopersicum leaves had a better performance reaching shorter larval developmental times and increasing the pupal weight compared to those fed on wild tomatoes. Overall, our study documents that agronomic selection for increased yields has altered the defensive and nutritional traits in tomato plants, affecting their resistance to T. absoluta.

Herbivory selects for tolerance and constitutive defence across stages of community succession.

Plants defend themselves from herbivory by either reducing damage (resistance) or minimizing its negative fitness effects with compensatory growth (tolerance). Herbivore pressure can fluctuate from year to year in an early secondary successional community, which can create temporal variation in selection for defence traits. We manipulated insect herbivory and successional age of the community as agents of natural selection in replicated common gardens with the perennial herb Solidago altissima. In these genotypic selection experiments, herbivory consistently selected for better defended plants in both successional communities. Herbivore suppression increased plant survival and the probability of flowering only in mid-succession. Despite these substantial differences in the effects of herbivory between early and mid-succession, the selection on defence traits did not change. Succession affected selection only on aboveground biomass, with positive selection in early but not mid-succession, suggesting an important role of competition in the selective environment. These results demonstrate that changes in the community that affect key life-history traits in an individual species can occur over very short timescales in a dynamic secondary successional environment. The resulting community context-driven variation in natural selection may be an important, yet overlooked, contributor to adaptive mosaics across populations.

Potassium Phosphite Activates Components Associated with Constitutive Defense Responses in Coffea arabica Cultivars.

Phosphites have been used as inducers of resistance, activating the defense of plants and increasing its ability to respond to the invasion of the pathogen. However, the mode of action of phosphites in defense responses has not yet been fully elucidated. The objective of this study was to evaluate the effect of potassium phosphite (KPhi) in coffee cultivars with different levels of resistance to rust to clarify the mechanism by which KPhi activates the constitutive defense of plants. To this end, we studied the expression of genes and the activity of enzymes involved in the defense pathway of salicylic acid (SA) and reactive oxygen species (ROS), in addition to the levels of total soluble phenolic compounds and soluble lignin. Treatment with KPhi induced constitutive defense responses in cultivars resistant and susceptible to rust. The results suggest that KPhi acts in two parallel defense pathways, SA and ROS, which are essential for the induction of systemic acquired resistance (SAR) when activated simultaneously. The activation of the mechanisms associated with defense routes demonstrates that KPhi is a potential inducer of resistance in coffee plants.

CYSRT1: An Antimicrobial Epidermal Protein that Can Interact with Late Cornified Envelope Proteins

Late cornified envelope (LCE) proteins are small cationic epidermal proteins with antimicrobial properties, and the combined deletion of LCE3B and LCE3C genes is a risk factor for psoriasis that affects skin microbiome composition. In a yeast two-hybrid screen, we identified CYSRT1 as an interacting partner of members of all LCE groups except LCE6. These interactions were confirmed in a mammalian cell system by coimmunoprecipitation. CYSRT1 is a protein of unknown function that is specifically expressed in cutaneous and oral epithelia and spatially colocalizes with LCE proteins in the upper layers of the suprabasal epidermis. Constitutive CYSRT1 expression is present in fully differentiated epidermis and can be further induced invivo by disruption of the skin barrier upon stratum corneum removal. Transcriptional regulation correlates to keratinocyte terminal differentiation but not to skin bacteria exposure. Similar to LCEs, CYSRT1 was found to have antibacterial activity against Pseudomonas aeruginosa. Comparative gene sequence analysis and protein amino acid alignment indicate that CYSRT1 is highly conserved among vertebrates and has putative antimicrobial activity. To summarize, we identified CYSRT1 in the outer skin layer, where it colocalizes with LCE proteins and contributes to the constitutive epidermal antimicrobial host defense repertoire.

Comparison of Individual Sensors in the Electronic Nose for Stress Detection in Forest Stands.

Forests are increasingly exposed to natural disturbances, including drought, wildfires, pest outbreaks, and windthrow events. Due to prolonged droughts in the last years in Europe, European forest stands significantly lost vitality, and their health condition deteriorated, leading to high mortality rates, especially, but not limited to, Norway spruce. This phenomenon is growing, and new regions are being affected; thus, it is necessary to identify stress in the early stages when actions can be taken to protect the forest and living trees. Current detection methods are based on field walks by forest workers or deploying remote sensing methods for coverage of the larger territory. These methods are based on changes in spectral reflectance that can detect attacks only at an advanced stage after the significant changes in the canopy. An innovative approach appears to be a method based on odor mapping, specifically detecting chemical substances which are present in the forest stands and indicate triggering of constitutive defense of stressed trees. The bark beetle attacking a tree, for example, produces a several times higher amount of defense-related volatile organic compounds. At the same time, the bark beetle has an aggregation pheromone to attract conspecifics to overcome the tree defense by mass attack. These substances can be detected using conventional chemical methods (solid-phase microextraction fibers and cartridges), and it is proven that they are detectable by dogs. The disadvantage of classic chemical analysis methods is the long sampling time in the forest, and at the same time, the results must be analyzed in the laboratory using a gas chromatograph. A potential alternative novel device appears to be an electronic nose, which is designed to detect chemical substances online (for example, dangerous gas leaks or measure concentrations above landfills, volcanic activity, etc.). We tested the possibility of early-stage stress detection in the forest stands using an electronic nose Sniffer4D and compared the individual sensors in it for detecting the presence of attacked and dead trees. Our results indicate the promising applicability of the electronic nose for stress mapping in the forest ecosystem, and more data collection could prove this approach.

Members of the tomato NRC4 h-NLR family augment each other in promoting basal immunity

Plants possess an efficient, two-tiered immune system to combat pathogens and pests. Several decades of research have characterized different features of these two well-known tiers, PTI and ETI (Pattern/ Effector-triggered Immunity). NLR (Nucleotide-binding domain Leucine-rich Repeat) receptors have been found to link PTI to ETI, and be required for full potentiation of plant immune responses in several systems. Intra-cellular helper-NLRs (h-NLRs) mediate ETI and have been focused on extensively in recent research.Previously, we investigated the roles of the h-NLR SlNRC4a in tomato immunity, finding that a specific mutation in this gene results in gain of function constitutive defense activation and broad disease resistance. Deletion of the entire NRC4 clade, which contains 3 genes, can compromise tomato immunity. Here, we decided to investigate the role of an additional clade member, SlNRC4b, in basal immunity. We generated a gain of function mutant in SlNRC4b using CRISPR-Cas9, as well as a double gain of function mutant in both genes. Similarly to the slnrc4a mutant, a slnrc4b mutant also possessed increased basal immunity and broad spectrum disease resistance. The double mutant displayed additive effects in some cases, with significant increases in resistance to fungal phytopathogens as compared with each of the single mutants. Our work confirms that the NRC4 family h-NLRs are important in the plant immune system, suggesting that this gene family has the potential to be promising in targeted agricultural adaptation in the Solanaceae family, promoting disease resistance and prevention of yield loss to pathogens.

The flowering time regulator FLK controls pathogen defense in Arabidopsis thaliana.

Plant disease resistance is a complex process that is maintained in an intricate balance with development. Increasing evidence indicates the importance of posttranscriptional regulation of plant defense by RNA binding proteins. In a genetic screen for suppressors of Arabidopsis (Arabidopsis thaliana) accelerated cell death 6-1 (acd6-1), a small constitutive defense mutant whose defense level is grossly in a reverse proportion to plant size, we identified an allele of the canonical flowering regulatory gene FLOWERING LOCUS K HOMOLOGY DOMAIN (FLK) encoding a putative protein with triple K homology (KH) repeats. The KH repeat is an ancient RNA binding motif found in proteins from diverse organisms. The relevance of KH-domain proteins in pathogen resistance is largely unexplored. In addition to late flowering, the flk mutants exhibited decreased resistance to the bacterial pathogen Pseudomonas syringae and increased resistance to the necrotrophic fungal pathogen Botrytis cinerea. We further found that the flk mutations compromised basal defense and defense signaling mediated by salicylic acid (SA). Mutant analysis revealed complex genetic interactions between FLK and several major SA pathway genes. RNA-seq data showed that FLK regulates expression abundance of some major defense- and development-related genes as well as alternative splicing of a number of genes. Among the genes affected by FLK is ACD6, whose transcripts had increased intron retentions influenced by the flk mutations. Thus, this study provides mechanistic support for flk suppression of acd6-1 and establishes that FLK is a multifunctional gene involved in regulating pathogen defense and development of plants.

O IMPACTO DA OPINIÃO PUBLICADA SOBRE O PODER JUDICIÁRIO

This article is dedicated to the legal study of the current situation of Brazilian democratic society based on its core elements, among which are the rule of law, legal security, and due process of law, seen as fundamental guarantees and limits of the precepts and objectives established in the 1988 Constitution of the Republic. The importance of this constitutional defense is discussed as derived from the possible political pact established since then, aimed at promoting a return to civil and political liberties in the country after two decades of dictatorship. It is in this context that the behavior of the Judiciary is observed, in light of its role instituted by the 1988 Constitution of the Republic, in an analysis focused on the theory of judicial decision. To this end, the production of judicial decisions as exceptional measures is investigated, if founded on opinions that are foreign to the constitutional dictates, without the primacy of the constitutionalized democratic mechanisms. In the analysis of judicial decisions through the procedural limits of republican institutions, it is verified whether or not there is an association with a media pseudo-public opinion, in which the public opinion built in a democratic public sphere is replaced by public expressions of private preferences, thus verifying to what extent they relate to the constitutional pact.

The Role of ABA in the Interaction between Citrus Fruit and Penicillium digitatum

Abscisic acid (ABA) protects citrus fruit against Penicillium digitatum infection. The global mechanisms involved in the role of ABA in the P. digitatum-citrus fruit interaction are unknown. Here, we determine the transcriptome differences between the Navelate (Citrus sinensis (L.) Osbeck) orange and its ABA-deficient mutant Pinalate, which is less resistant to infection. Low ABA levels may affect both the constitutive mechanisms that protect citrus fruit against P. digitatum and early responses to infection. The repression of terpenoid, phenylpropanoid and glutation metabolism; of oxidation-reduction processes; and of processes related to the defense response to fungus and plant hormone signal transduction may be one part of the constitutive defense reduced in the mutant against P. digitatum. Our results also provide potential targets for developing P. digitatum-citrus fruit-resistant varieties. Of those up-regulated by ABA, a thaumatin protein and a bifunctional inhibitor/LTP, which are relevant in plant immunity, were particularly remarkable. It is also worth highlighting chlorophyllase 1 (CLH1), induced by infection in Pinalate, and the OXS3 gene, which was down-regulated by ABA, because the absence of OXS3 activates ABA-responsive genes in plants.

Constitutive and inducible defense in Eucalyptus determines the feeding host of Gonipterus platensis, denoting specific plant-insect coevolution and a strategy for resistance improvement

Defoliation caused by Gonipterus platensis on Eucalyptus seriously impacts tree growth rate and forest production. The weevil’s feeding preference has sometimes limited which species of Eucalyptus to plant, although the plant’s metabolic features that govern such choice still need to be uncovered. We used metabolomics to reveal the chemical traits mediating this interaction, focusing on a model formed by two Eucalyptus species with markedly different susceptibility, E. globulus (susceptible), and E. nitens (resistant). Our results suggest that the insect’s feeding preference strongly depends on the Eucalyptus species’ constitutive metabolome, especially on the stilbenes and hydrolysable tannins accumulation. The susceptible E. globulus could not produce such classes of metabolite either constitutively or after herbivory, which indicated an apparent lack of critical enzymes for biosynthesis of these substances, such as stilbene synthase (STS) and gallate 1-β-glucosyltransferase. On the other hand, it seems that no matter how toxic the systemic defense induced in E. globulus after herbivory could be to an insect, counteradaptations, apparently evolved by the weevil, may efficiently detoxify them. This may result from plant-insect coevolution, given their common geographical origin. Inter-specific hybridizations between E. nitens and E. globulus have adapted hybrid species better to low temperatures and frost conditions, consequently being propagated for plantations in temperate regions. Thus, this research lays the groundwork for selecting the best parent genotypes and obtained hybrids, aiming to warrant the transfer of key resistance traits to progenies as an attractive strategy for future breeding programs.

Plant defense under Arctic light conditions: Can plants withstand invading pests?

Global warming is predicted to change the growth conditions for plants and crops in regions at high latitudes (>60° N), including the Arctic. This will be accompanied by alterations in the composition of natural plant and pest communities, as herbivorous arthropods will invade these regions as well. Interactions between previously non-overlapping species may occur and cause new challenges to herbivore attack. However, plants growing at high latitudes experience less herbivory compared to plants grown at lower latitudes. We hypothesize that this finding is due to a gradient of constitutive chemical defense towards the Northern regions. We further hypothesize that higher level of defensive compounds is mediated by higher level of the defense-related phytohormone jasmonate. Because its biosynthesis is light dependent, Arctic summer day light conditions can promote jasmonate accumulation and, hence, downstream physiological responses. A pilot study with bilberry (Vaccinium myrtillus) plants grown under different light regimes supports the hypothesis.

Issues of Implementation of the Fair Trial in the Albanian System: Analysis in the Framework of the Constitutional Court and ECHR's Jurisprudence on Albania's Cases

The process of a fair trial constitutes an important part of human right standards, for which Albania is making efforts to develop. Article 6 (1) of the European Convention on Human Rights (ECHR), being the main tool in the area of fundamental rights and freedoms, lists the components of a fair, independent, impartial, legal and public trial within a reasonable time applicable in both civil and criminal trials. The paper aims to present an overview of the evolution of this principle in the Albanian constitutional system in order to understand how this principle has evolved in a former dictatorship such as Albania and how much this principle conforms to the standards sanctioned under Article 6 (1) of the ECHR. As one of the most significant legal events in Albania, judicial reform’s impact on the justice system is also analysed regarding the application of the standards of a fair trial. Naturally, all components of a fair trial are of essential importance, but considering gaps in enforcement and issues of their practical misinterpretation, this paper is focused in components such as: access to justice, trial within a reasonable time and trial by an independent and impartial court. Through the jurisprudence of the Albanian Constitutional Court and European Court of Human Rights on cases against Albania, the present paper outlines and seeks to address the matters of enforcement of such components in the Albanian system, such as: How is the constitutional defence of a free trial provided and what has been the Constitutional Court’s role in this regard? How have ECHR’s guidelines on cases against Albania affected the correction of misinterpretations in the national system? How has the judicial reform affected the enforcement of such components, and what are the subsequent problems and challenges? In conclusion, we present some opinions regarding the need to increase the standard of the defence of these components referring to a fair trial, particularly in the area where the largest number of problems have been identified by the practice.
 
 Received: 21 August 2022 / Accepted: 10 October 2022 / Published: 5 November 2022

Salt Stress Tolerance in Casuarina glauca: Insights from the Branchlets Transcriptome.

Climate change and the accelerated rate of population growth are imposing a progressive degradation of natural ecosystems worldwide. In this context, the use of pioneer trees represents a powerful approach to reverse the situation. Among others, N2-fixing actinorhizal trees constitute important elements of plant communities and have been successfully used in land reclamation at a global scale. In this study, we have analyzed the transcriptome of the photosynthetic organs of Casuarina glauca (branchlets) to unravel the molecular mechanisms underlying salt stress tolerance. For that, C. glauca plants supplied either with chemical nitrogen (KNO3+) or nodulated by Frankia (NOD+) were exposed to a gradient of salt concentrations (200, 400, and 600 mM NaCl) and RNA-Seq was performed. An average of ca. 25 million clean reads was obtained for each group of plants, corresponding to 86,202 unigenes. The patterns of differentially expressed genes (DEGs) clearly separate two groups: (i) control- and 200 mM NaCl-treated plants, and (ii) 400 and 600 mM NaCl-treated plants. Additionally, although the number of total transcripts was relatively high in both plant groups, the percentage of significant DEGs was very low, ranging from 6 (200 mM NaCl/NOD+) to 314 (600 mM NaCl/KNO3+), mostly involving down-regulation. The vast majority of up-regulated genes was related to regulatory processes, reinforcing the hypothesis that some ecotypes of C. glauca have a strong stress-responsive system with an extensive set of constitutive defense mechanisms, complemented by a tight mechanism of transcriptional and post-transcriptional regulation. The results suggest that the robustness of the stress response system in C. glauca is regulated by a limited number of genes that tightly regulate detoxification and protein/enzyme stability, highlighting the complexity of the molecular interactions leading to salinity tolerance in this species.

Combined –omics framework reveals how ant symbionts benefit the Neotropical ant-plant Tococa quadrialata at different levels

SummaryAnt-plant defensive mutualism is a widely studied phenomenon, where ants protect their host plants (myrmecophytes) against herbivores in return for the provision of nesting sites and food. However, few studies addressed the influence of ant colonization and herbivory on the plant’s metabolism. We chose the Amazonian plant Tococa quadrialata, living in association with Azteca cf. tonduzi ants for an ant-exclusion study to reveal the chemistry behind this symbiosis. We found that colonized plants did not only benefit from protection but also from increased amino acid and nitrogen content, enabling better performance even in an herbivore-free environment. In contrast, ant-deprived T. quadrialata plants accumulated more ellagitannins, a major class of constitutive defense compounds. Moreover, herbivory-induced jasmonate-mediated defense responses, including the upregulation of signaling and defense genes and the emission of volatiles irrespective of colonization status. Altogether, we show how ant-colonization can influence the general and defense-related metabolism and performance of myrmecophytes.

Growth and fecundity of Spodoptera frugiperda on native Zea mays and the teosinte Z. luxurians, from Oaxaca, Mexico

Resistance to Spodoptera frugiperda (Lepidoptera: Noctuidae) damage has been documented in some Mexican maize races and teosintes. There are approximately 31 races of native maize and three races of teosinte in Oaxaca state, but little is known about their resistance to insect damage. This study compared the development and fecundity of S. frugiperda fed on native maize and the teosinte Zea luxurians, from Oaxaca, Mexico. No significant differences were determined in the development parameters of males and females according to the host plant types, except the pupal weight of males, which was higher on teosinte (0.189 g) than on native maize (0.174 g). Duration from hatching to adult emergence was 28.96 to 30.17 d on native maize and 28.51 to 30.34 d on teosinte. Females emerged before males in both host plant types. The sex ratio was approximately 0.5 for both sexes. Larval weight was higher on teosinte (0.451 to 0.459 g) than on native maize (0.442 to 0.454 g). According to the fecundity parameters, no significant differences in the duration of oviposition, the number of eggs per egg mass, eggs per female, and eggs per host plant types were determined. Fitness Index was positively correlated with the pupal weight of both sexes and the fecundity parameters of S. frugiperda females. Our results demonstrated that larval feeding on native maize and teosinte did not affect the development parameters and fecundity of S. frugiperda. Constitutive defenses in native maize leaves were similar to those of teosinte.

Constitutive and Induced Defenses in Long-lived Pines Do Not Trade Off but Are Influenced by Climate.

Plants resist herbivores and pathogens by using constitutive (baseline) and inducible (change in defense after an attack) defenses. Inducibility has long been predicted to trade off with constitutive defense, reflecting the economic use of resources. However, empirical evidence for such tradeoffs is variable, and we still lack understanding about when and where defense trade-offs occur. We tested for tradeoffs between constitutive and induced defenses in natural populations of three species of long-lived pines (Pinus balfouriana, P. flexilis, P. longaeva) that differ greatly in constitutive defense and resistance to mountain pine beetle (MPB, Dendroctonus ponderosae). We also assessed how climate influenced constitutive and inducible defenses. At seven high-elevation sites in the western U.S., we simulated MPB attack to induce defenses and measured concentrations of terpene-based phloem defenses on days 0, 15, and 30. Constitutive and induced defenses did not trade off among or within species. Simulated MPB attack induced large increases in defense concentrations in all species independent of constitutive levels. MPB and its symbiotic fungi typically kill trees and thus could be selective forces maintaining strong inducibility within and among species. The contrasting constitutive concentrations in these species could be driven by the adaptation for specializing in harsh, high-elevation environments (e.g., P. balfouriana and P. longaeva) or by competition (e.g., P. flexilis), though these hypotheses have not been empirically examined. Climate influenced defenses, with the greatest concentrations of constitutive and induced defenses occurring at the coldest and driest sites. The interactions between climate and defenses have implications for these species under climate change.

Chemical defense strategies, induction timing, growth, and trade‐offs inPinus aristataandPinus flexilis

AbstractTrade‐offs between plant defense investment and fitness traits, including growth, are often invoked to explain evolutionary strategies targeted at resisting herbivores. ManyPinusspecies have specialized herbivores, including the mountain pine beetle (MPB),Dendroctonus ponderosae, and have historically been a focus of defense investigations. We compared defense traits of two high‐elevationPinusspecies,P. aristataandP. flexilis, that are hosts to MPB and hypothesized to have different growth and defense traits and potential trade‐offs. Interspecific differences were assessed by sampling trees within the same stands, and intraspecific differences were assessed by sampling stands at sites across latitudes where both species co‐occurred. Constitutive defenses were measured at Day 0, and the timing, concentration, and composition of an induced resin defense response were assessed by sampling at 1, 4, and 30 days following either mechanical wounding only or a simulated MPB attack using its primary fungal symbiontGrosmannia clavigera. At Day 4, induced resin concentrations did not differ between mechanical wounding and simulated MPB attack in either species. By Day 30, resin defense concentrations in response to simulated MPB attack were greater than those in response to mechanical wounding and were >19‐fold greater than constitutive levels. Results suggest that initial induced resin defense responses in the two species are likely generalized, with a delayed response that is targeted specifically at MPB andG. clavigera. At all sites,P. aristatahad higher concentrations of constitutive and Day‐30 induced resin defenses thanP. flexilis, althoughP. flexilisinduced proportionately more. Trade‐offs in growth and defense between the species were only found at the two most climatically favorable sites whereP. aristatagrew slower thanP. flexilis. No trade‐offs were found between the two defense types at either biological scale. Overall, our findings highlight that the two pine species growing in the same stands (1) have a delayed response to a specialized native herbivore and fungal symbiont, (2) only exhibited interspecific defense–growth trade‐offs at two climatically favorable sites, and showed no intraspecific defense–growth trade‐offs, (3) showed no trade‐offs between constitutive and induced defenses at either biological scale, and (4) have evolved different defense strategies.

Constitutive Defense Mechanisms Have a Major Role in the Resistance of Woodland Strawberry Leaves Against Botrytis cinerea.

The necrotrophic fungus Botrytis cinerea is a major threat to strawberry cultivation worldwide. By screening different Fragaria vesca genotypes for susceptibility to B. cinerea, we identified two genotypes with different resistance levels, a susceptible genotype F. vesca ssp. vesca Tenno 3 (T3) and a moderately resistant genotype F. vesca ssp. vesca Kreuzkogel 1 (K1). These two genotypes were used to identify the molecular basis for the increased resistance of K1 compared to T3. Fungal DNA quantification and microscopic observation of fungal growth in woodland strawberry leaves confirmed that the growth of B. cinerea was restricted during early stages of infection in K1 compared to T3. Gene expression analysis in both genotypes upon B. cinerea inoculation suggested that the restricted growth of B. cinerea was rather due to the constitutive resistance mechanisms of K1 instead of the induction of defense responses. Furthermore, we observed that the amount of total phenolics, total flavonoids, glucose, galactose, citric acid and ascorbic acid correlated positively with higher resistance, while H2O2 and sucrose correlated negatively. Therefore, we propose that K1 leaves are more resistant against B. cinerea compared to T3 leaves, prior to B. cinerea inoculation, due to a lower amount of innate H2O2, which is attributed to a higher level of antioxidants and antioxidant enzymes in K1. To conclude, this study provides important insights into the resistance mechanisms against B. cinerea, which highly depend on the innate antioxidative profile and specialized metabolites of woodland strawberry leaves.

Advances in understanding Norway spruce natural resistance to needle bladder rust infection: transcriptional and secondary metabolites profiling

BackgroundNeedle rust caused by the fungus Chrysomyxa rhododendri causes significant growth decline and increased mortality of young Norway spruce trees in subalpine forests. Extremely rare trees with enhanced resistance represent promising candidates for practice-oriented reproduction approaches. They also enable the investigation of tree molecular defence and resistance mechanisms against this fungal disease. Here, we combined RNA-Seq, RT-qPCR and secondary metabolite analyses during a period of 38 days following natural infection to investigate differences in constitutive and infection-induced defence between the resistant genotype PRA-R and three susceptible genotypes.ResultsGene expression and secondary metabolites significantly differed among genotypes from day 7 on and revealed already known, but also novel candidate genes involved in spruce molecular defence against this pathogen. Several key genes related to (here and previously identified) spruce defence pathways to needle rust were differentially expressed in PRA-R compared to susceptible genotypes, both constitutively (in non-symptomatic needles) and infection-induced (in symptomatic needles). These genes encoded both new and well-known antifungal proteins such as endochitinases and chitinases. Specific genetic characteristics concurred with varying phenolic, terpene, and hormone needle contents in the resistant genotype, among them higher accumulation of several flavonoids (mainly kaempferol and taxifolin), stilbenes, geranyl acetone, α-ionone, abscisic acid and salicylic acid.ConclusionsCombined transcriptional and metabolic profiling of the Norway spruce defence response to infection by C. rhododendri in adult trees under subalpine conditions confirmed the results previously gained on artificially infected young clones in the greenhouse, both regarding timing and development of infection, and providing new insights into genes and metabolic pathways involved. The comparison of genotypes with different degrees of susceptibility proved that several of the identified key genes are differently regulated in PRA-R, and that the resistant genotype combines a strong constitutive defence with an induced response in infected symptomatic needles following fungal invasion. Genetic and metabolic differences between the resistant and susceptible genotypes indicated a more effective hypersensitive response (HR) in needles of PRA-R that prevents penetration and spread of the rust fungus and leads to a lower proportion of symptomatic needles as well as reduced symptom development on the few affected needles.