Resilient Genotypes Research Articles

Identification of key chlorophyll fluorescence parameters as biomarkers for dryland wheat under future climate conditions.

Nowadays, climate change is the primary factor shaping the future of food and nutritional security. To investigate the interactive effects of various climate variables on photosynthetic efficiency, an experiment was conducted using 10 dryland wheat genotypes. These genotypes were exposed to different conditions: temperatures of 25 ± 3°C and 34 ± 3°C, carbon dioxide concentrations of 380 ± 50 ppm and 800 ± 50 ppm, and irrigation regimes of 50% field capacity and well-watered. Our results indicated that the wheat genotypes responded differently to both individual and combined climate stress factors. The traditional winter wheat genotype *Sardari*, along with the newly developed dryland wheat genotype *Ivan*, exhibited resilience to anticipated climate conditions. This resilience was reflected in enhancements in photochemical quantum efficiency parameters (Y(II), qP, and qL) under combined stress conditions. Resilient genotypes demonstrated superior regulation of the stomatal conductance (GS) and electron transport rate (ETR) under elevated temperature and CO2 levels. Principal component analysis (PCA) revealed significant correlations between chlorophyll fluorescence parameters and climate factors, such as NPQ with temperature, Y(NO) with CO2, qL in response to drought stress, and both qP and Y(II) with the interactions among temperature, CO2, and drought stress. Elevated CO2 reduced the ETR and GS across all genotypes. Our findings underscore the importance of assessing not only fundamental chlorophyll fluorescence parameters like Fm and Fo but also the efficiency of NPQ and Y(II) to understand climate change impacts on dryland wheat genotypes. We suggest that these parameters could serve as valuable biomarkers for breeding programs aimed at improving plant adaptation to future dryland climate conditions.

Stomatal and Non-Stomatal Leaf Responses during Two Sequential Water Stress Cycles in Young Coffea canephora Plants

Understanding the dynamics of physiological changes involved in the acclimation responses of plants after their exposure to repeated cycles of water stress is crucial to selecting resilient genotypes for regions with recurrent drought episodes. Under such background, we tried to respond to questions as: (1) Are there differences in the stomatal-related and non-stomatal responses during water stress cycles in different clones of Coffea canephora Pierre ex A. Froehner? (2) Do these C. canephora clones show a different response in each of the two sequential water stress events? (3) Is one previous drought stress event sufficient to induce a kind of “memory” in C. canephora? Seven-month-old plants of two clones (’3V’ and ‘A1’, previously characterized as deeper and lesser deep root growth, respectively) were maintained well-watered (WW) or fully withholding the irrigation, inducing soil water stress (WS) until the soil matric water potential (Ψmsoil) reached ≅ −0.5 MPa (−500 kPa) at a soil depth of 500 mm. Two sequential drought events (drought-1 and drought-2) attained this Ψmsoil after 19 days and were followed by soil rewatering until a complete recovery of leaf net CO2 assimilation rate (Anet) during the recovery-1 and recovery-2 events. The leaf gas exchange, chlorophyll a fluorescence, and leaf reflectance parameters were measured in six-day frequency, while the leaf anatomy was examined only at the end of the second drought cycle. In both drought events, the WS plants showed reduction in stomatal conductance and leaf transpiration. The reduction in internal CO2 diffusion was observed in the second drought cycle, expressed by increased thickness of spongy parenchyma in both clones. Those stomatal and anatomical traits impacted decreasing the Anet in both drought events. The ‘3V’ was less influenced by water stress than the ‘A1’ genotype in Anet, effective quantum yield in PSII photochemistry, photochemical quenching, linear electron transport rate, and photochemical reflectance index during the drought-1, but during the drought-2 event such an advantage disappeared. Such physiological genotype differences were supported by the medium xylem vessel area diminished only in ‘3V’ under WS. In both drought cycles, the recovery of all observed stomatal and non-stomatal responses was usually complete after 12 days of rewatering. The absence of photochemical impacts, namely in the maximum quantum yield of primary photochemical reactions, photosynthetic performance index, and density of reaction centers capable of QA reduction during the drought-2 event, might result from an acclimation response of the clones to WS. In the second drought cycle, the plants showed some improved responses to stress, suggesting “memory” effects as drought acclimation at a recurrent drought.

Development of Climate Resilient Genotypes in Desi Chickpea (Cicer arietinum L.)

For development of climate resilient genotypes of chickpea for yield and yield contributing characters the present study was undertaken at Pulses Improvement Project, MPKV, Rahuri during Rabi season of 2021-22. The twelve genotypes and four check varieties were evaluated under three different environmental conditions. The data was subjected to ANOVA and Eberthart and Russel model. The analysis of pooled variance showed a significant connection among genotypes, environment (Linear) and genotypes x environment (Linear) almost for all characters except for number of seeds per pod. The genotypes Phule G 181603, Phule G 181609, Phule G 181667, Vijay and Phule Vikrant exhibited average stability for grain yield per plant over all three environments. The varieties Digvijay and Phule Vikram was found below average stable so they could be suitable for poor environment and genotypes Phule G 181102 and Phule G 1210-16-1 showed stability under favorable environments.

Identifying critical growth stage and resilient genotypes in cowpea under drought stress contributes to enhancing crop tolerance for improvement and adaptation in Cameroon

Identifying critical growth stage and resilient genotypes in cowpea under drought stress contributes to enhancing crop tolerance for improvement and adaptation in Cameroon

Assessing drought tolerance in advance wheat genotypes using stress tolerance indices

Wheat, an important crop of Nepal, is significantly affected by drought, leading to severe yield losses. Thus, an experiment was conducted to assess effect of drought on wheat traits and to identify drought resilient genotypes comparing stress tolerance indices. Altogether seventy-two genotypes including checks were evaluated under drought and non-stress condition in an alpha-lattice design with two replications at the research block of National Rice Research Program, Hardinath, Nepal during winter of 2019/20. Analysis of variance revealed significant genotypic differences (p<0.01) in traits such as days to heading, anthesis, and maturity, plant height, flag leaf area, spike length, grains per spike, 1000-grain weight, and grain yield under both conditions. The combined analysis of variance showed that genotype, environment, and their interaction significantly influenced most traits. The environment was the dominant factor, accounting for 86.2% of the variation in grain yield, followed by genotype (9.5%) and genotype-environment interaction (4.3%). Among the nine quantitative traits assessed, grain yield was most severely affected due to drought, experiencing a substantial reduction of 63%. To assess drought tolerance, six indices (TOL, SSI, MP, GMP, HMP, and STI) were calculated based on grain yield data. Most indices identified genotypes NL1373, NL1308, NL1407, BL4868, and BL4947 as highly drought-tolerant. Among the indices, MP, STI, and GMP were the most reliable for measuring stress tolerance due to their strong positive correlation with yield under both conditions. These identified genotypes are promising candidates for breeding programs aimed at developing drought-resilient wheat varieties, thereby enhancing food security in drought-affected regions.

Unlocking genetic insights: Evaluating wheat RILs for physiobiochemical traits under terminal heat stress conditions

BackgroundThe increasing impacts of heat stress on wheat production due to climate change has entailed the development of heat-resilient crop varieties. To address this, two hundred recombinant inbred lines (RILs) derived from a cross between WH711/WH1021 were evaluated in a randomized block design (RBD) with two replications at CCSHAU, Hisar, during 2018-19 under heat stress and non-stress conditions. Heat stress was induced by altering the date of sowing so that the grain filling stage coincide with heat stress.ResultsHeat stress adversely affects RILs performance, as illustrated by alterations in phenotypic traits. Highest coefficients of variations were recorded for TAA, CTD 1, WUE, CTD 2, Cc and A under non-stress and heat stress conditions whereas gs, WUEi and GY under non-stress and SPAD 1, SPAD 2, GY and NDVI 2 under heat-stress conditions recorded moderate estimates of coefficient of variations. CTD 2, TAA, E, WUE and A displayed a significant occurrence of both high heritability and substantial genetic advance under non-stress. Similarly, CTD 2, NDVI 2, A, WUEi, SPAD 2, gs, E, Ci, MDA and WUE exhibited high heritability with high genetic advance under heat-stress conditions.ConclusionsComplementary and duplicate types of interactions with number of controlling genes were observed for different parameters depending on the traits and environments. RILs 41, 42, 59, 74, 75, 180 and 194 were categorized as heat tolerant RILs. Selection preferably for NDVI 1, RWC, TAA, A, E and WUEi to accumulate heat tolerance favorable alleles in the selected RILs is suggested for development of heat resilient genotypes for sustainable crop improvement. The results showed that traits such as such as NDVI, RWC, TAA, A, E, and WUEi, can be effective for developing heat-resilient wheat genotypes and ensuring sustainable crop improvement.

Surviving a Double-Edged Sword: Response of Horticultural Crops to Multiple Abiotic Stressors.

Climate change-induced weather events, such as extreme temperatures, prolonged drought spells, or flooding, pose an enormous risk to crop productivity. Studies on the implications of multiple stresses may vary from those on a single stress. Usually, these stresses coincide, amplifying the extent of collateral damage and contributing to significant financial losses. The breadth of investigations focusing on the response of horticultural crops to a single abiotic stress is immense. However, the tolerance mechanisms of horticultural crops to multiple abiotic stresses remain poorly understood. In this review, we described the most prevalent types of abiotic stresses that occur simultaneously and discussed them in in-depth detail regarding the physiological and molecular responses of horticultural crops. In particular, we discussed the transcriptional, posttranscriptional, and metabolic responses of horticultural crops to multiple abiotic stresses. Strategies to breed multi-stress-resilient lines have been presented. Our manuscript presents an interesting amount of proposed knowledge that could be valuable in generating resilient genotypes for multiple stressors.

Dare to be resilient: the key to future pesticide-free orchards?

Considering the urgent need for more sustainable fruit tree production, it is high time to find durable alternatives to the systematic use of phytosanitary products in orchards. To this end, resilience can deliver a number of benefits. Relying on a combination of tolerance, resistance, and recovery traits, disease resilience appears as a cornerstone to cope with the multiple pest and disease challenges over an orchard's lifetime. Here, we describe resilience as the capacity of a tree to be minimally affected by external disturbances or to rapidly bounce back to normal functioning after being exposed to these disturbances. Based on a literature survey largely inspired from research on livestock, we highlight different approaches for dissecting phenotypic and genotypic components of resilience. In particular, multisite experimental designs and longitudinal measures of so-called 'resilience biomarkers' are required. We identified a list of promising biomarkers relying on ecophysiological and digital measurements. Recent advances in high-throughput phenotyping and genomics tools will likely facilitate fine scale temporal monitoring of tree health, allowing identification of resilient genotypes with the calculation of specific resilience indicators. Although resilience could be considered as a 'black box' trait, we demonstrate how it could become a realistic breeding goal.

Genome-wide analysis to uncover how Pocillopora acuta survives the challenging intertidal environment

Characterisation of genomic variation among corals can help uncover variants underlying trait differences and contribute towards genotype prioritisation in coastal restoration projects. For example, there is growing interest in identifying resilient genotypes for transplantation, and to better understand the genetic processes that allow some individuals to survive in specific conditions better than others. The coral species Pocillopora acuta is known to survive in a wide range of habitats, from reefs artificial coastal defences, suggesting its potential use as a starter species for ecological engineering efforts involving coral transplantation onto intertidal seawalls. However, the intertidal section of coastal armour is a challenging environment for corals, with conditions during periods of emersion being particularly stressful. Here, we scanned the entire genome of P. acuta corals to identify the regions harbouring single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) that separate intertidal colonies (n = 18) from those found in subtidal areas (n = 21). Findings revealed 74,391 high quality SNPs distributed across 386 regions of the P. acuta genome. While the majority of the detected SNPs were in non-coding regions, 12% were identified in exons (i.e. coding regions). Functional SNPs that were significantly associated with intertidal colonies were found in overrepresented genomic regions linked to cellular homeostasis, metabolism, and signalling processes, which may represent local environmental adaptation in the intertidal. Interestingly, regions that exhibited CNVs were also associated with metabolic and signalling processes, suggesting P. acuta corals living in the intertidal have a high capacity to perform biological functions critical for survival in extreme environments.

Future-Proofing Agriculture: De Novo Domestication for Sustainable and Resilient Crops.

The worldwide agricultural system confronts a significant challenge represented by the increasing demand for food in the face of a growing global population. This challenge is exacerbated by a reduction in cultivable land and the adverse effects of climate change on crop yield quantity and quality. Breeders actively embrace cutting-edge omics technologies to pursue resilient genotypes in response to these pressing issues. In this global context, new breeding techniques (NBTs) are emerging as the future of agriculture, offering a solution to introduce resilient crops that can ensure food security, particularly against challenging climate events. Indeed, the search for domestication genes as well as the genetic modification of these loci in wild species using genome editing tools are crucial steps in carrying out de novo domestication of wild plants without compromising their genetic background. Current knowledge allows us to take different paths from those taken by early Neolithic farmers, where crop domestication has opposed natural selection. In this process traits and alleles negatively correlated with high resource environment performance are probably eradicated through artificial selection, while others may have been lost randomly due to domestication and genetic bottlenecks. Thus, domestication led to highly productive plants with little genetic diversity, owing to the loss of valuable alleles that had evolved to tolerate biotic and abiotic stresses. Recent technological advances have increased the feasibility of de novo domestication of wild plants as a promising approach for crafting optimal crops while ensuring food security and using a more sustainable, low-input agriculture. Here, we explore what crucial domestication genes are, coupled with the advancement of technologies enabling the precise manipulation of target sequences, pointing out de novo domestication as a promising application for future crop development.

Rapid and low-cost screening for single and combined effects of drought and heat stress on the morpho-physiological traits of African eggplant (Solanum aethiopicum) germplasm.

Drought and heat are two stresses that often occur together and may pose significant risks to crops in future climates. However, the combined effects of these two stressors have received less attention than single-stressor investigations. This study used a rapid and straightforward phenotyping method to quantify the variation in 128 African eggplant genotype responses to drought, heat, and the combined effects of heat and drought at the seedling stage. The study found that the morphophysiological traits varied significantly among the 128 eggplants, highlighting variation in response to abiotic stresses. Broad-sense heritability was high (> 0.60) for chlorophyll content, plant biomass and performance index, electrolyte leakage, and total leaf area. Positive and significant relationships existed between biomass and photosynthetic parameters, but a negative association existed between electrolyte leakage and morpho-physiological traits. The plants underwent more significant stress when drought and heat stress were imposed concurrently than under single stresses, with the impact of drought on the plants being more detrimental than heat. There were antagonistic effects on the morphophysiology of the eggplants when heat and drought stress were applied together. Resilient genotypes such as RV100503, RV100501, JAMBA, LOC3, RV100164, RV100169, LOC 3, RV100483, GH5155, RV100430, GH1087, GH1087*, RV100388, RV100387, RV100391 maintained high relative water content, low electrolyte leakage, high Fv/Fm ratio and performance index, and increased biomass production under abiotic stress conditions. The antagonistic interactions between heat and drought observed here may be retained or enhanced during several stress combinations typical of plants' environments and must be factored into efforts to develop climate change-resilient crops. This paper demonstrates improvised climate chambers for high throughput, reliable, rapid, and cost-effective screening for heat and drought and combined stress tolerance in plants.

Combination of RNAseq and RADseq to Identify Physiological and Adaptive Responses to Acidification in the Eastern Oyster (Crassostrea virginica).

Ocean acidification (OA) is a major stressor threatening marine calcifiers, including the eastern oyster (Crassostrea virginica). In this paper, we provide insight into the molecular mechanisms associated with resilience to OA, with the dual intentions of probing both acclimation and adaptation potential in this species. C. virginica were spawned, and larvae were reared in control or acidified conditions immediately after fertilization. RNA samples were collected from larvae and juveniles, and DNA samples were collected from juveniles after undergoing OA-induced mortality and used to contrast gene expression (RNAseq) and SNP (ddRADseq) profiles from animals reared under both conditions. Results showed convergence of evidence from both approaches, particularly in genes involved in biomineralization that displayed significant changes in variant frequencies and gene expression levels among juveniles that survived acidification as compared to controls. Downregulated genes were related to immune processes, supporting previous studies demonstrating a reduction in immunity from exposure to OA. Acclimation to OA via regulation of gene expression might confer short-term resilience to immediate threats; however, the costs may not be sustainable, underscoring the importance of selection of resilient genotypes. Here, we identified SNPs associated with survival under OA conditions, suggesting that this commercially and ecologically important species might have the genetic variation needed for adaptation to future acidification. The identification of genetic features associated with OA resilience is a highly-needed step for the development of marker-assisted selection of oyster stocks for aquaculture and restoration activities.

Phenotyping agronomic and physiological traits in peanut under mid‐season drought stress using UAV‐based hyperspectral imaging and machine learning

AbstractAgronomic and physiological traits in peanut (Arachis hypogaea) are important to breeders for selecting high‐yielding and resilient genotypes. However, direct measurement of these traits is labor‐intensive and time‐consuming. This study assessed the feasibility of using unmanned aerial vehicles (UAV)‐based hyperspectral imaging and machine learning (ML) techniques to predict three agronomic traits (biomass, pod count, and yield) and two physiological traits (photosynthesis and stomatal conductance) in peanut under drought stress. Two different approaches were evaluated. The first approach employed eighty narrowband vegetation indices as input features for an ensemble model that included K‐nearest neighbors, support vector regression, random forest, and multi‐layer perceptron (MLP). The second approach utilized mean and standard deviation of canopy spectral reflectance per band. The resultant 400 features were used to train a deep learning (DL) model consisting of one‐dimensional convolutional layers followed by an MLP regressor. Predictions of the agronomic traits obtained using feature learning and DL (R2 = 0.45–0.73; symmetric mean absolute percentage error [sMAPE] = 24%–51%) outperformed those obtained using feature engineering and conventional ML models (R2 = 0.44–0.61, sMAPE = 27%–59%). In contrast, the ensemble model had a slightly better performance in predicting physiological traits (R2 = 0.35–0.57; sMAPE = 37%–70%) compared to the results obtained from the DL model (R2 = 0.36–0.52; sMAPE = 47%–64%). The results showed that the combination of UAV‐based hyperspectral imaging and ML techniques have the potential to assist breeders in rapid screening of genotypes for improved yield and drought tolerance in peanut.

SCREENING OF CHICKPEA GENOTYPES AGAINST SALINITY STRESS IN PETRI DISH ENVIRONMENT

The leguminous crop chickpea (Cicer arietinum L.) has a great potential for nutrition, antioxidants, proteins, lipids, and carbs. Due to concerns with soil salinity/sodicity and climate change, the area used for chickpea cultivation is shrinking daily and the overall yield has decreased. Ten varieties of chickpea were subjected to salinity stress in a petri dish at four different NaCl concentrations: 0 mM, 50 mM, 100 mM, and 150 mM in a controlled condition experiment. The findings of the experiment revealed that Chattan and KK-1 do not survive under salinity stress. While Punjab-2008 and KK-2 demonstrated strong resilience to salinity stress. The results showed that at 0 mM of NaCl, KK-2 and Punjab-2008 had the highest germination rates (99%), followed by Bittle-98 and CM-98 (98%) The Chattan and KK-1 do not exhibit any germination at 150 mM NaCl. The data showed that Fakhr-e-thal had the smallest Radicle length (0.05 cm) at 150 mM NaCl, whereas Bhakkar-2011 at 50 mM NaCl had the largest Radicle length (4.90 cm). In comparison to 0 mM NaCl, the plumule length (cm) of the various chickpea genotypes showed that Bhakkar-2011 had the longest plumules (3.09 cm), Chattan had the shortest (0.80 cm), and KK-1 had no values at the greatest salinity levels. It is therefore concluded that increasing salinity badly affects the germination and growth in chickpea, but this stress can be mitigated by using salinity resilient genotypes.

Evaluation of bread wheat (Triticum aestivum L.) genotypes for drought tolerance using morpho-physiological traits under drought-stressed and well-watered conditions.

Increasing frequency of drought spells occasioned by changing climatic conditions, coupled with rise in demand for bread wheat, calls for the development of high yielding drought resilient genotypes to enhance bread wheat production in areas with moisture deficit. This study was designed to identify and select drought-tolerant bread wheat genotypes using morpho-physiological traits. One hundred and ninety-six bread wheat genotypes were evaluated in greenhouse and field experiments, under well-watered (80% of field capacity) and drought-stressed (35% of field capacity) conditions, for two years. Data were collected on five morphological traits (flag leaf size, flag leaf angle, flag leaf rolling, leaf waxiness and resistance to diseases) and 14 physiological traits. Relative water content (RWC), Excised leaf water retention (ELWR), Relative water loss (RWL), Leaf membrane stability index (LMSI), as well as Canopy temperature depression (CTD) at heading (CTDH), anthesis (CTDA), milking (CTDM), dough stage (CTDD) and ripening (CTDR) were estimated. Similarly, leaf chlorophyll content (SPAD reading) was recorded at heading (SPADH), anthesis (SPADA), milking (SPADM), dough stage (SPADD), and ripening (SPADR). Significant (p<0.01) genotypic differences were found for the traits under both well-watered and drought-stressed conditions. Associations of RWL with SPADH, SPADA, SPADM, SPADD and SPADR were significant (p<0.01) and negative under both watering regimes. The first three principal components accounted for 92.0% and 88.4% of the total variation under well-watered and drought-stressed conditions, respectively and comprised all the traits. The traits CTDD, CTDM, CTDR, SPADH, SPADA, SPADM, SPADD and SPADR with genotypes Alidoro, ET-13A2, Kingbird, Tsehay, ETBW 8816, ETBW 9027, ETBW9402, ETBW 8394 and ETBW 8725 were associated under both conditions. Genotypes with narrow flag leaves, erect flag leaf angles, fully rolled flag leaves, heavily waxed leaves, and resistant to disease manifested tolerance to drought stress. The identified traits and genotypes could be exploited in future breeding programmes for the development of bread wheat genotypes with tolerance to drought.

Crop Wild Relatives: A Valuable Source of Tolerance to Various Abiotic Stresses

Global climate change is one of the major constraints limiting plant growth, production, and sustainability worldwide. Moreover, breeding efforts in the past years have focused on improving certain favorable crop traits, leading to genetic bottlenecks. The use of crop wild relatives (CWRs) to expand genetic diversity and improve crop adaptability seems to be a promising and sustainable approach for crop improvement in the context of the ongoing climate challenges. In this review, we present the progress that has been achieved towards CWRs exploitation for enhanced resilience against major abiotic stressors (e.g., water deficiency, increased salinity, and extreme temperatures) in crops of high nutritional and economic value, such as tomato, legumes, and several woody perennial crops. The advances in -omics technologies have facilitated the elucidation of the molecular mechanisms that may underlie abiotic stress tolerance. Comparative analyses of whole genome sequencing (WGS) and transcriptomic profiling (RNA-seq) data between crops and their wild relative counterparts have unraveled important information with respect to the molecular basis of tolerance to abiotic stressors. These studies have uncovered genomic regions, specific stress-responsive genes, gene networks, and biochemical pathways associated with resilience to adverse conditions, such as heat, cold, drought, and salinity, and provide useful tools for the development of molecular markers to be used in breeding programs. CWRs constitute a highly valuable resource of genetic diversity, and by exploiting the full potential of this extended allele pool, new traits conferring abiotic-stress tolerance may be introgressed into cultivated varieties leading to superior and resilient genotypes. Future breeding programs may greatly benefit from CWRs utilization for overcoming crop production challenges arising from extreme environmental conditions.

Modeling CNS neuronal‐glial interactions relevant to Alzheimer’s Disease and ADRD with microglia and neurons derived from human induced pluripotent stem cells

AbstractBackgroundCNS neurons and microglia participate in neuroimmune pathways linked to Alzheimer’s Disease (AD) and AD Related Dementias (ADRD). However, CNS neurons and microglia cannot be isolated from living people, and primary microglia harvested post‐mortem rapidly de‐differentiate in culture. hiPSC‐neurons and hiPSC‐MG represent a practical alternative for in vitro research, as they are human‐derived, upscalable, and can be made from people with AD/ADRD‐sensitive or ‐resilient genotypes. We are developing high‐throughput assays utilizing hiPSC‐neurons/‐MG, to explore interactions between these cell types and pathways relevant to AD, and to test compounds for beneficial effects on neuronal health.MethodhiPSC‐neurons (excitatory) were purchased from Fujifilm CDI or differentiated in‐house (with kits from Elixirgen). hiPSC‐MG were differentiated in‐house from hiPSCs via a protocol in which yolk sac‐like structures are produced as an intermediary step. Mono‐ or cocultures were prepared in 96‐ or 384‐well dishes. Results were obtained via automated digital microscopy, with cellular structures and biomarkers analyzed via high content analysis (HCA) and cell activity (calcium or voltage transients) analyzed via Kinetic Image Cytometry; in certain experiments, LDH release, a general measure of cytotoxicity, was also assayed.ResultCoculture of hiPSC‐MG with hiPSC‐neurons led to a 2‐fold increase in neurites. hiPSC‐MG also elicited calcium transients in the hiPSC‐neurons via close contact. The APOE‐e4 gene variant confers the greatest risk for late‐onset AD, and proteolysis of ApoE4 may produce neurotoxic fragments. In our hands, a fragment of ApoE4 (ApoECFp17, aa 1‐151) induced LDH release in both hiPSC‐neurons and hiPSC‐MG, indicating cytotoxicity, whereas the corresponding fragment of ApoE3 had no effect; additionally, the toxic effect on hiPSC‐MG was partially blocked by PH002 (an ApoE4 “structure corrector”) and by RAP (a protein that blocks ApoE4 binding to cell‐surface receptors).ConclusionOur data demonstrate that hiPSC‐MG alter neurite expression and calcium transient activity in cocultured hiPSC‐neurons, and that the aa 1‐151 fragment of ApoE4 is toxic to human neurons and microglia, which could potentially play a role in AD etiology. Future research will incorporate hiPSC‐astrocytes into the cultures to further model CNS neuronal‐glial interactions and elucidate pathways relevant to AD/ADRD.

The Rediscovery of Traditional Maize Agrobiodiversity: A Study Case from Northern Italy

Nowadays, agriculture is under the pressure of climate change and new pathogen outbreaks while farmers are requiring breeders to develop more resistant and resilient genotypes. The genetic base for breeding may be increased through appropriate conservation, description and characterization of local varieties and germplasm collections that have never been used in breeding, and which could be sources of useful alleles. In this framework, the present paper focuses on eight maize landraces of the eastern part of Emilia-Romagna, derived from the Italian maize collection sampled in 1954. Landraces are characterized by a short cycle length and different kernel types—mainly flint-like or an intermediate type of yellow or yellow–orange color—while dent landraces are less represented. Pigmented and white corns are absent even though one landrace (Va213) showed the presence of scattered blue kernels on yellow ears. Ear shape is frequently conical, a trait associated with drought-resistance and common in Italian traditional landraces. Genetic characterization was carried out on 529 individuals by using 10 SSR markers. A total of 68 different alleles, ranging from 4 for markers (phi084 and umc1401) to 11 (phi031) and from 27 (Va217) to 50 (Va211), were evidenced at the individual and population level. AMOVA analysis revealed a small amount (19%) of variability between populations, as supported also by PCoA, with the only exception of Va217, which is different from the others, as evidenced also by phylogenetic analysis. Population structure analysis resulted in the identification of three and four population levels, which are consistent with previous results.

Biochemical properties of pomegranate (Punica granatum L.) juice as influenced by severe water stress

This research investigates the influence of two irrigation regimes on juice chemical and biochemical characteristics of eleven Mediterranean pomegranate (Punica granatum L.) cultivars during two consecutive years (2019–2020). Control trees were fully irrigated (FI) at 100% of crop evapotranspiration (ETc), and the stressed ones were subjected to a sustained deficit irrigation (SDI) of 50% ETc. Results showed that water stress effect on juice quality attributes significantly varied depending on genotype with divergent amplitude variations and patterns under each year. There were significant decreases in soluble solids content (TSS), titratable acidity and pH on 8 cultivars. Soluble sugars content showed a significant decrease in 5 cultivars, combined with a decrease in amino acids content (AAC) for 2 cultivars. The SDI treatment decreased phenolic compounds content in 8 cultivars, with an often significant effect on anthocyanins content, thereby reducing the antioxidant activity level. According to principal component analysis, variations in TSS and AAC were the most discriminating changes induced by water stress applied over all studied cultivars. Overall, this study showed that SDI often leads to produce pomegranate juice with lower quality. However, the significant genotypic differences herein revealed suggest to move forward with in-depth analyzes to select resilient genotypes to cope with the climate change, particularly in arid lands.

Capturing crop adaptation to abiotic stress using image-based technologies.

Farmers and breeders aim to improve crop responses to abiotic stresses and secure yield under adverse environmental conditions. To achieve this goal and select the most resilient genotypes, plant breeders and researchers rely on phenotyping to quantify crop responses to abiotic stress. Recent advances in imaging technologies allow researchers to collect physiological data non-destructively and throughout time, making it possible to dissect complex plant responses into quantifiable traits. The use of image-based technologies enables the quantification of crop responses to stress in both controlled environmental conditions and field trials. This paper summarizes phenotyping imaging technologies (RGB, multispectral and hyperspectral sensors, among others) that have been used to assess different abiotic stresses including salinity, drought and nitrogen deficiency, while discussing their advantages and drawbacks. We present a detailed review of traits involved in abiotic tolerance, which have been quantified by a range of imaging sensors under high-throughput phenotyping facilities or using unmanned aerial vehicles in the field. We also provide an up-to-date compilation of spectral tolerance indices and discuss the progress and challenges in machine learning, including supervised and unsupervised models as well as deep learning.