Decoupling of impact factors reveals the response of German winter wheat yields to climatic changes.

Yield development of agricultural crops over time is not merely the result of genetic and agronomic factors, but also the outcome of a complex interaction between climatic and site-specific soil conditions. However, the influence of past climatic changes on yield trends remains unclear, particularly under consideration of different soil conditions. In this study, we determine the effects of single agrometeorological factors on the evolution of German winter wheat yields between 1958 and 2015 from 298 published nitrogen (N)-fertilization experiments. For this purpose, we separate climatic from genetic and agronomic yield effects using linear mixed effect models and estimate the climatic influence based on a coefficient of determination for these models. We found earlier occurrence of wheat growth stages, and shortened development phases except for the phase of stem elongation. Agrometeorological factors are defined as climate covariates related to the growth of winter wheat. Our results indicate a general and strong effect of agroclimatic changes on yield development, in particular due to increasing mean temperatures and heat stress events during the grain-filling period. Except for heat stress days with more than 31°C, yields at sites with higher yield potential were less prone to adverse weather effects than at sites with lower yield potential. Our data furthermore reveal that a potential yield levelling, as found for many West-European countries, predominantly occurred at sites with relatively low yield potential and about one decade earlier (mid-1980s) compared to averaged yield data for the whole of Germany. Interestingly, effects related to high precipitation events were less relevant than temperature-related effects and became relevant particularly during the vegetative growth phase. Overall, this study emphasizes the sensitivity of yield productivity to past climatic conditions, under consideration of regional differences, and underlines the necessity of finding adaptation strategies for food production under ongoing and expected climate change.

Environmental triggers for photosynthetic protein turnover determine the optimal nitrogen distribution and partitioning in the canopy.

Plants continually adjust the photosynthetic functions in their leaves to fluctuating light, thereby optimizing the use of photosynthetic nitrogen (Nph) at the canopy level. To investigate the complex interplay between external signals during the acclimation processes, a mechanistic model based on the concept of protein turnover (synthesis and degradation) was proposed and parameterized using cucumber grown under nine combinations of nitrogen and light in growth chambers. Integrating this dynamic model into a multi-layer canopy model provided accurate predictions of photosynthetic acclimation of greenhouse cucumber canopies grown under high and low nitrogen supply in combination with day-to-day fluctuations in light at two different levels. This allowed us to quantify the degree of optimality in canopy nitrogen use for maximizing canopy carbon assimilation, which was influenced by Nph distribution along canopy depth or Nph partitioning between functional pools. Our analyses suggest that Nph distribution is close to optimum and Nph reallocation is more important under low nitrogen. Nph partitioning is only optimal under a light level similar to the average light intensity during acclimation, meaning that day-to-day light fluctuations inevitably result in suboptimal Nph partitioning. Our results provide insights into photoacclimation and can be applied to crop model improvement.

High light aggravates functional limitations of cucumber canopy photosynthesis under salinity.

Background and Aims: Most crop species are glycophytes, and salinity stress is one of the most severe abiotic stresses reducing crop yields worldwide. Salinity affects plant architecture and physiological functions by different mechanisms, which vary largely between crop species and determine the susceptibility or tolerance of a crop species to salinity. Methods: Experimental data from greenhouse cucumber (Cucumis sativus), a salt-sensitive species, grown under three salinity levels were interpreted by combining a functional-structural plant model and quantitative limitation analysis of photosynthesis. This approach allowed the quantitative dissection of canopy photosynthetic limitations into architectural and functional limitations. Functional limitations were further dissected into stomatal (Ls), mesophyll (Lm) and biochemical (Lb). Key Results: Architectural limitations increased rapidly after the start of the salinity treatment and became stronger than the sum of functional limitations (Ls + Lm + Lb) under high salinity. Stomatal limitations resulted from ionic effects and were much stronger than biochemical limitations, indicating that canopy photosynthesis was more limited by the effects of leaf sodium on stomatal regulation than on photosynthetic enzymes. Sensitivity analyses suggested that the relative importance of salinity effects on architectural and functional limitations depends on light conditions, with high light aggravating functional limitations through salinity effects on stomatal limitations. Conclusions: Salinity tolerance of cucumber is more likely to be improved by traits related to leaf growth and stomatal regulation than by traits related to tissue tolerance to ion toxicity, especially under high light conditions.

A new method to estimate photosynthetic parameters through net assimilation rate-intercellular space CO2 concentration (A-Ci ) curve and chlorophyll fluorescence measurements.

Gas exchange (GE) and chlorophyll fluorescence (CF) measurements are widely used to noninvasively study photosynthetic parameters, for example the rates of maximum Rubisco carboxylation (Vcmax ), electron transport rate (J), daytime respiration (Rd ) and mesophyll conductance (gm ). Existing methods for fitting GE data (net assimilation rate-intercellular space CO2 concentration (A-Ci ) curve) are based on two assumptions: gm is unvaried with CO2 concentration in the intercellular space (Ci ); and light absorption (α) and the proportion of quanta absorbed by photosystem II (ß) are constant in the data set. These may result in significant bias in estimating photosynthetic parameters. To avoid the above-mentioned hypotheses, we present a new method for fitting A-Ci curves and CF data simultaneously. This method was applied to a data set obtained from cucumber (Cucumis sativus) leaves of various leaf ages and grown under eight different light conditions. The new method had significantly lower root mean square error and a lower rate of failures compared with previously published methods (6.72% versus 24.1%, respectively) and the effect of light conditions on Vcmax and J was better observed. Furthermore, the new method allows the estimation of a new parameter, the fraction of incoming irradiance harvested by photosystem II, and the dependence of gm on Ci .

Quantitative trait loci controlling leaf appearance and curd initiation of cauliflower in relation to temperature.

KEY MESSAGE: QTL regions on chromosomes C06 and C09 are involved in temperature dependent time to curd induction in cauliflower. Temperature is the main environmental factor influencing curding time of cauliflower (Brassica oleracea var. botrytis). Temperatures above 20-22 °C inhibit development towards curding even in many summer cultivars. To identify quantitative trait loci (QTL) controlling curding time and its related traits in a wide range of different temperature regimes from 12 to 27 °C, a doubled haploid (DH) mapping population segregating for curding time was developed and days to curd initiation (DCI), leaf appearance rate (LAR), and final leaf number (FLN) were measured. The population was genotyped with 176 single nucleotide polymorphism (SNP) markers. Composite interval mapping (CIM) revealed repeatedly detected QTL for DCI on C06 and C09. The estimated additive effect increased at high temperatures. Significant QTL × environment interactions (Q × E) for FLN and DCI on C06 and C09 suggest that these hotspot regions have major influences on temperature mediated curd induction. 25 % of the DH lines did not induce curds at temperatures higher than 22 °C. Applying a binary model revealed a QTL with LOD >15 on C06. Nearly all lines carrying the allele of the reliable early maturing parental line (PL) on that locus induced curds at high temperatures while only half of the DH lines carrying the allele of the unreliable PL reached the generative phase during the experiment. Large variation in LAR was observed. QTL for LAR were detected repeatedly in several environments on C01, C04 and C06. Negative correlations between LAR and DCI and QTL co-localizations on C04 and C06 suggest that LAR has also effects on development towards curd induction.

Disentangling the contributions of osmotic and ionic effects of salinity on stomatal, mesophyll, biochemical and light limitations to photosynthesis.

There are conflicting opinions on the relative importance of photosynthetic limitations under salinity. Quantitative limitation analysis of photosynthesis provides insight into the contributions of different photosynthetic limitations, but it has only been applied under saturating light conditions. Using experimental data and modelling approaches, we examined the influence of light intensity on photosynthetic limitations and quantified the osmotic and ionic effects of salinity on stomatal (LS ), mesophyll (LM ), biochemical (LB ) and light (LL ) limitations in cucumber (Cucumis sativus L.) under different light intensities. Non-linear dependencies of LS , LM and LL to light intensity were found. Osmotic effects on LS and LM increased with the salt concentration in the nutrient solution (Ss ) and the magnitude of LM depended on light intensity. LS increased with the Na(+) concentration in the leaf water (Sl ) and its magnitude depended on Ss . Biochemical capacity declined linearly with Sl but, surprisingly, the relationship between LB and Sl was influenced by Ss . Our results suggest that (1) improvement of stomatal regulation under ionic stress would be the most effective way to alleviate salinity stress in cucumber and (2) osmotic stress may alleviate the ionic effects on LB but aggravate the ionic effects on LS .

Quantification of the effects of architectural traits on dry mass production and light interception of tomato canopy under different temperature regimes using a dynamic functional-structural plant model.

There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a model crop, a dynamic functional-structural plant model (FSPM) was constructed, parameterized, and evaluated to analyse the effects of temperature on architectural traits, which strongly influence canopy light interception and shoot dry mass. The FSPM predicted the organ growth, organ size, and shoot dry mass over time with high accuracy (>85%). Analyses of this FSPM showed that, in comparison with the reference canopy, shoot dry mass may be affected by leaf angle by as much as 20%, leaf curvature by up to 7%, the leaf length:width ratio by up to 5%, internode length by up to 9%, and curvature ratios and leaf arrangement by up to 6%. Tomato canopies at low temperature had higher canopy density and were more clumped due to higher leaf area and shorter internodes. Interestingly, dry mass production and light interception of the clumped canopy were more sensitive to changes in architectural traits. The complex interactions between architectural traits, canopy light interception, dry mass production, and environmental conditions can be studied by the dynamic FSPM, which may serve as a tool for designing a canopy structure which is 'ideal' in a given environment.

Genetic dissection of temperature-dependent sorghum growth during juvenile development.

KEY MESSAGE: Promising genome regions for improving cold tolerance of sorghum were identified on chromosomes SBI-01, SBI-03, SBI-07, and SBI-10. Chlorophyll fluorescence had no major effect on growth rates at low temperatures. Developing fast growing sorghum seedlings is an important breeding goal for temperate climates since low springtime temperatures are resulting in a prolonged juvenile development. The adaptation of sorghum to tropical and subtropical highlands gives hint for certain genetic variation. The goals of the present study were to detect marker-trait associations for leaf and dry matter growth rate and for chlorophyll fluorescence and content (SPAD) in relation to temperature. A diversity set comprising 194 genotypes was tested in eight controlled environments with temperatures ranging from 9.4 to 20.8 °C. Significant marker-trait associations (p < 0.05) were identified for each individual temperature regime and on the parameters of regression analyses describing the responses of growth or chlorophyll related traits to temperatures. The diversity set was fingerprinted with 171 diversity array technology (DArT) and 31 simple-sequence repeat (SSR) markers. SSRs were used to analyze the population structure while association studies were performed on DArT markers. Promising marker-trait associations for growth rates in relation to temperature were detected on chromosomes SBI-01, SBI-03, SBI-07, and SBI-10. Many promising loci were also significantly associated to the results obtained in individual low-temperature environments. Marker-trait associations for chlorophyll content and fluorescence did occasionally co-locate to those for growth during juvenile development but there was no evidence supporting our hypothesis that seedling growth at low temperatures is largely influenced by SPAD or fluorescence.

What is the most prominent factor limiting photosynthesis in different layers of a greenhouse cucumber canopy?

BACKGROUND AND AIMS: Maximizing photosynthesis at the canopy level is important for enhancing crop yield, and this requires insights into the limiting factors of photosynthesis. Using greenhouse cucumber (Cucumis sativus) as an example, this study provides a novel approach to quantify different components of photosynthetic limitations at the leaf level and to upscale these limitations to different canopy layers and the whole plant. METHODS: A static virtual three-dimensional canopy structure was constructed using digitized plant data in GroIMP. Light interception of the leaves was simulated by a ray-tracer and used to compute leaf photosynthesis. Different components of photosynthetic limitations, namely stomatal (S(L)), mesophyll (M(L)), biochemical (B(L)) and light (L(L)) limitations, were calculated by a quantitative limitation analysis of photosynthesis under different light regimes. KEY RESULTS: In the virtual cucumber canopy, B(L) and L(L) were the most prominent factors limiting whole-plant photosynthesis. Diffusional limitations (S(L) + M(L)) contributed <15% to total limitation. Photosynthesis in the lower canopy was more limited by the biochemical capacity, and the upper canopy was more sensitive to light than other canopy parts. Although leaves in the upper canopy received more light, their photosynthesis was more light restricted than in the leaves of the lower canopy, especially when the light condition above the canopy was poor. An increase in whole-plant photosynthesis under diffuse light did not result from an improvement of light use efficiency but from an increase in light interception. Diffuse light increased the photosynthesis of leaves that were directly shaded by other leaves in the canopy by up to 55%. CONCLUSIONS: Based on the results, maintaining biochemical capacity of the middle-lower canopy and increasing the leaf area of the upper canopy would be promising strategies to improve canopy photosynthesis in a high-wire cucumber cropping system. Further analyses using the approach described in this study can be expected to provide insights into the influences of horticultural practices on canopy photosynthesis and the design of optimal crop canopies.

Compensation of adverse growing media effects on plant growth and morphology by supplemental LED lighting.

There is an increasing interest in alternatives to peat in growing media due to environmental constraints. However, plants grown in peat substitutes often show impaired growth compared to plants grown in peat-based media. Hence, it would be interesting to know whether these deficiencies can be compensated by supplementing other growth factors, e.g. light. The present study aims to investigate the interactive nature between growing media and supplemental lighting on plant growth and morphology, and to examine whether supplemental light emitting diode (LED) lighting may compensate adverse growing media effects. Basil (Ocimum basilicum L.) and Chinese cabbage (Brassica rapa subsp. pekinensis) were grown in different growing media consisting of peat, green compost, coconut pulp, wood fibre, perlite and sphagnum moss under blue, red and far-red supplemental LED lighting. We found significant interactions between growing media and supplemental photosynthetically active radiation (PAR) on plant growth, morphology and development. At low light intensities, peat-based and substituted growing media performed similarly, whereas with increasing light intensities the peat-based growing media significantly outperformed their alternatives. The substrate choice determines the required amount of supplemental light to compensate for adverse growing media effects and the amount varies depending on plant species and season. Thereby, it was indicated that red light alleviates adverse growing media effects best. We also found that far-red light is not effective when background PAR is low and becomes more effective under high background PAR. The implications and prospects of the results are discussed.

Stage-specific genotype-by-environment interactions determine yield components in wheat.

In cereal crops, environmental fluctuations affect different physiological processes during various developmental phases associated with the formation of yield components. Because these effects are coupled with cultivar-specific phenology, studies investigating environmental responses in different cultivars can give contradictory results regarding key phases impacting yield performance. To dissect how genotype-by-environment interactions affect grain yield in winter wheat, we estimated the sensitivities of yield components to variation in global radiation, temperature and precipitation in 220 cultivars across 81 time-windows ranging from double ridge to seed desiccation. Environmental sensitivity responses were prominent in the short-term physiological subphases of spike and kernel development, causing phenologically dependent, stage-specific genotype-by-environment interactions. Here we reconcile contradicting findings from previous studies and show previously undetected effects; for example, the positive impact of global radiation on kernel weight during canopy senescence. This deep insight into the three-way interactions between phenology, yield formation and environmental fluctuations provides comprehensive new information for breeding and modelling cereal crops.

Genetic dissection of the temperature dependent emergence processes in sorghum using a cumulative emergence model and stability parameters.

Among the major limitations for cultivating biomass sorghum in temperate regions is low temperature in spring that results in low and non-uniform emergence. The adaptation of sorghum to tropical and subtropical highlands gives hint of genetic variation in cold tolerance during emergence. The objective of the present study was to detect marker-trait associations for parameters describing the emergence process under different temperature regimes. A diversity set comprising 194 genotypes was tested in nine controlled environments with temperatures ranging from 9.4 to 19.9 °C. The genotypes were fingerprinted with 171 DArT markers. A piecewise linear regression model carried out on cumulative emergence was used to estimate genotype mean performance across environments and to carry out stability analysis on the parameters of the regression model. Base temperature (T (b)) and thermal time required for emergence (E (TS)) were determined based on median time to emergence data. Identified QTL positions were compared to marker-trait associations for final emergence percentages under low (FEP(cold)) and normal (FEP(normal)) temperatures. QTL for mean final emergence percentage (FEP), FEP(cold) and FEP(normal,) T (b) and E (TS) were detected on SBI-01. Other QTL-rich regions were located on SBI-03, SBI-04, SBI-06, SBI-08, and SBI-09. Marker-trait associations for T (b) and E (TS) co-localized to QTL for the across environment stability of FEP and the median time to emergence or emergence rate, respectively. We conclude that genome regions on six chromosomes highly influencing cold tolerance during emergence are promising for regional association studies and for the development of stable markers for marker-assisted selection.

Interspecific variation in leaf traits, photosynthetic light response, and whole-plant productivity in amaranths (Amaranthus spp. L.).

Photosynthetic light response curve parameters help us understand the interspecific variation in photosynthetic traits, leaf acclimation status, carbon uptake, and plant productivity in specific environments. These parameters are also influenced by leaf traits which rely on species and growth environment. In accessions of four amaranth species (Amaranthus. hybridus, A. dubius, A. hypochondriacus, and A. cruentus), we determined variations in the net photosynthetic light response curves and leaf traits, and analysed the relationships between maximum gross photosynthetic rate, leaf traits, and whole-plant productivity. Non-rectangular hyperbolae were used for the net photosynthesis light response curves. Maximum gross photosynthetic rate (Pgmax) was the only variant parameter among the species, ranging from 22.29 to 34.21 µmol m-2 s-1. Interspecific variation existed for all the leaf traits except leaf mass per area and leaf inclination angle. Stomatal conductance, nitrogen, chlorophyll, and carotenoid contents, as well as leaf area correlated with Pgmax. Stomatal conductance and leaf nitrogen explained much of the variation in Pgmax at the leaf level. At the plant level, the slope between absolute growth rate and leaf area showed a strong linear relationship with Pgmax. Overall, A. hybridus and A. cruentus exhibited higher Pgmax at the leaf level and light use efficiency at the whole-plant level than A. dubius, and A. hypochondriacus. Thus, A. hybridus and A. cruentus tended to be more efficient with respect to carbon assimilation. These findings highlight the correlation between leaf photosynthetic characteristics, other leaf traits, and whole plant productivity in amaranths. Future studies may explore more species and accessions of Amaranthus at different locations or light environments.

Modelling photo-modulated internode elongation in growing glasshouse cucumber canopies.

• Growing glasshouse plant canopies are exposed to natural fluctuations in light quantity, and the dynamically changing canopy architecture induces local variations in light quality. This modelling study aimed to analyse the importance of both light signals for an accurate prediction of individual internode lengths. • We conceptualized two model approaches for estimating final internode lengths (FILs). The first one is only photosynthetically active radiation (PAR)-sensitive and ignores canopy architecture, whereas the second approach uses a functional-structural growth model for considering variations in both PAR and red : far-red (R : FR) ratio (L-Cucumber). Internode lengths measured in three experiments were used for model parameterization and evaluation. • The overall trends for the simulated FILs using the exclusively PAR-sensitive model approach were already in line with the measured FILs, but they underestimated FILs at higher ranks. L-Cucumber provided considerably better FIL predictions under various light conditions and canopy architectures. • Both light signals are needed for an accurate estimation of the FILs, and only L-Cucumber is able to consider R : FR signals from the growing canopy. Yet this study highlights the significance of the PAR signal for predicting FILs as neighbour effects increase, which indicates a potential role of photosynthate signalling in internode elongation.

Simplification of a light-based model for estimating final internode length in greenhouse cucumber canopies.

BACKGROUND AND AIMS: Light quantity and quality affect internode lengths in cucumber (Cucumis sativus), whereby leaf area and the optical properties of the leaves mainly control light quality within a cucumber plant community. This modelling study aimed at providing a simple, non-destructive method to predict final internode lengths (FILs) using light quantity and leaf area data. METHODS: Several simplifications of a light quantity and quality sensitive model for estimating FILs in cucumber have been tested. The direct simplifications substitute the term for the red : far-red (R : FR) ratios, by a term for (a) the leaf area index (LAI, m(2) m(-2)) or (b) partial LAI, the cumulative leaf area per m(2) ground, where leaf area per m(2) ground is accumulated from the top of each plant until a number, n, of leaves per plant is reached. The indirect simplifications estimate the input R : FR ratio based on partial leaf area and plant density. KEY RESULTS: In all models, simulated FILs were in line with the measured FILs over various canopy architectures and light conditions, but the prediction quality varied. The indirect simplification based on leaf area of ten leaves revealed the best fit with measured data. Its prediction quality was even higher than of the original model. CONCLUSIONS: This study showed that for vertically trained cucumber plants, leaf area data can substitute local light quality data for estimating FIL data. In unstressed canopies, leaf area over the upper ten ranks seems to represent the feedback of the growing architecture on internode elongation with respect to light quality. This highlights the role of this domain of leaves as the primary source for the specific R : FR signal controlling the final length of an internode and could therefore guide future research on up-scaling local processes to the crop level.

Dry matter partitioning models for the simulation of individual fruit growth in greenhouse cucumber canopies.

BACKGROUND AND AIMS: Growth imbalances between individual fruits are common in indeterminate plants such as cucumber (Cucumis sativus). In this species, these imbalances can be related to differences in two growth characteristics, fruit growth duration until reaching a given size and fruit abortion. Both are related to distribution, and environmental factors as well as canopy architecture play a key role in their differentiation. Furthermore, events leading to a fruit reaching its harvestable size before or simultaneously with a prior fruit can be observed. Functional-structural plant models (FSPMs) allow for interactions between environmental factors, canopy architecture and physiological processes. Here, we tested hypotheses which account for these interactions by introducing dominance and abortion thresholds for the partitioning of assimilates between growing fruits. METHODS: Using the L-System formalism, an FSPM was developed which combined a model for architectural development, a biochemical model of photosynthesis and a model for assimilate partitioning, the last including a fruit growth model based on a size-related potential growth rate (R(P)). Starting from a distribution proportional to R(P), the model was extended by including abortion and dominance. Abortion was related to source strength and dominance to sink strength. Both thresholds were varied to test their influence on fruit growth characteristics. Simulations were conducted for a dense row and a sparse isometric canopy. KEY RESULTS: The simple partitioning models failed to simulate individual fruit growth realistically. The introduction of abortion and dominance thresholds gave the best results. Simulations of fruit growth durations and abortion rates were in line with measurements, and events in which a fruit was harvestable earlier than an older fruit were reproduced. CONCLUSIONS: Dominance and abortion events need to be considered when simulating typical fruit growth traits. By integrating environmental factors, the FSPM can be a valuable tool to analyse and improve existing knowledge about the dynamics of assimilates partitioning.

Seasonal Efficiency of Supplemental LED Lighting on Growth and Photomorphogenesis of Sweet Basil.

For decisions on supplemental lighting a quantitative knowledge of the plants' responses to light under varying conditions is fundamental. In this study, we developed light dose-response curves of growth and morphological traits for Ocimum basilicum L. and examined the effects of light color (blue, red, and white plus far-red) and natural environment (season) on these curves. Four greenhouse experiments were conducted throughout the year to determine the efficiencies of the light regimes on growth and their effects on plant morphology. A special aspect was the photosynthetic efficiency of far-red light. Linear and monomolecular relationships were found for the relationships between plant traits and supplemental light dose. Traits related to biomass productivity increased linearly with light dose whereas some morphological characters showed a saturation behavior. Red light and white plus far-red light were more efficient in plant dry weight production than blue light, and the plants adapted differently to the light qualities: higher biomass under red light was related to a plant architecture more favorable for light capture, i.e., taller plants and bigger leaves. White plus far-red light, on the other hand, increased leaf mass per area (LMA) and light use efficiency (LUE). Blue light resulted in lowest plant light interception and LUE. Considering photosynthetic effects of near-infrared light (PPFD800, 400-800 nm) instead of photosynthetic photon flux density (PPFD700, 400-700 nm) led to strongly reduced efficiencies. Traits related to photosynthesis such as dry weight, LMA and LUE were particularly affected by PPFD800. There were no interactions between the efficiencies of the different light colors and the seasons. Efficiencies of all light regimes were significantly lower during summer compared to spring and winter. Higher dry weight production during summer compared to winter and spring were a consequence of increased light interception rather than changes in LUE. The observed differences in seasonal efficiencies were directly linked to the amount of natural light present as indicated by changes in the ratio of supplemental to natural light.

Enhanced Abiotic Stress Tolerance of Vicia faba L. Plants Heterologously Expressing the PR10a Gene from Potato.

Pathogenesis-related (PR) proteins are known to play relevant roles in plant defense against biotic and abiotic stresses. In the present study, we characterize the response of transgenic faba bean (Vicia faba L.) plants encoding a PR10a gene from potato (Solanum tuberosum L.) to salinity and drought. The transgene was under the mannopine synthetase (pMAS) promoter. PR10a-overexpressing faba bean plants showed better growth than the wild-type plants after 14 days of drought stress and 30 days of salt stress under hydroponic growth conditions. After removing the stress, the PR10a-plants returned to a normal state, while the wild-type plants could not be restored. Most importantly, there was no phenotypic difference between transgenic and non-transgenic faba bean plants under well-watered conditions. Evaluation of physiological parameters during salt stress showed lower Na+-content in the leaves of the transgenic plants, which would reduce the toxic effect. In addition, PR10a-plants were able to maintain vegetative growth and experienced fewer photosystem changes under both stresses and a lower level of osmotic stress injury under salt stress compared to wild-type plants. Taken together, our findings suggest that the PR10a gene from potato plays an important role in abiotic stress tolerance, probably by activation of stress-related physiological processes.

Biodiversity in European agricultural landscapes: transformative societal changes needed.

Reversing the decline of biodiversity in European agricultural landscapes is urgent. We suggest eight measures addressing politics, economics, and civil society to instigate transformative changes in agricultural landscapes. We emphasize the need for a well-informed society and political measures promoting sustainable farming by combining food production and biodiversity conservation.