Addressing crop responses to drought and nitrogen stress is crucial for improving resilience and ensuring sustainable agriculture under changing climatic conditions. This study investigates the physiological responses of wheat (Videodur [DU], Sensas [SW]) and barley (Tiroler Imperial [SG1], Amidala [SG2]) cultivars to drought and nitrogen stress during early reproductive to full maturity stages (BBCH 70 to 90) using infrared (IR) and visible near-infrared–shortwave infrared (VNIR-SWIR) hyperspectral imaging. Evapotranspiration (ET) and respiration were analyzed as functions of mean plant temperature (Tplant), light intensity, plant water status (indicated by the Normalized Difference Water Index, NDWI), and air humidity. Results revealed that drought stress significantly reduced NDWI and ET while increasing Tplant, with wheat cultivars showing greater sensitivity to water deficit. Barley, particularly SG2, exhibited superior water retention and thermal regulation, highlighting its potential for drought resilience with consistently higher NDWI values and lower Tplant. Temporal analysis identified the reproductive stage as the most vulnerable to stress, with a sharp decline in NDWI and rise in Tplant, emphasizing the need for stage-specific interventions. Regression models explained 74% of ET variance and 67% of respiration variance, underscoring the predictive power of NDWI and Tplant as proxies for plant water status and metabolic activity. Real-time evapotranspiration (ET) measurements using a balance during precision watering further validated the predictive capabilities of NDWI and Tplant. These findings provide valuable insights into growth stage-specific breeding programs and sustainable crop management strategies under environmental stress conditions.

Microalgae productivity is majorly influenced by changing seasonal conditions affecting its micromorphology, physiology and metabolic activity. In this study, microalga belonging to the Picochlorum sp. isolated from tropical habitat was found to be better adapted and twice as productive in the summer tropical simulations compared to winter. Reduced growth in winter was metabolically corroborated by an increase in carbon squandering pathways in winter simulating conditions through the upregulation of photorespiratory pathway and 2-fold increase in biomass accumulation in summer simulation through the upregulation of carbon conserving pathways. Ultrastructural studies revealed increased thylakoid membrane space in winter simulation compared to summer simulating conditions affecting diffusion and metabolite distribution. Furthermore, reduction in photosystem II electron transport rate with nearly half the performance index was observed in winter. This study narrows down the possible metabolic, physiological, and ultrastructural changes at seasonal abiotic variations critically affecting the microalgae carbon fixation and productivity.

Globally there are three major challenges in the 21st century, related to the conventional agriculture-based food production system. They are very suitably defined under the United Nations sustainable development goals. These three challenges are food security, nutrition security, and climate security. With ever-increasing global population, decreasing arable land area, soil erosion, and scarcity of freshwater availability, these challenges aggravate ecological homeostasis. Such interconnected challenges are of paramount importance and can be overcome by some extent through climate-smart agriculture practices such as the use of renewable energy sources to drive agriculture, crop diversification, crop rotation, and organic agriculture. However, the need of the hour is to leapfrog toward climate-resilient cultivation practices. Deployment of soilless indoor cultivation technology is one such long-term sustainable strategy. Adoption of soilless technology provides a great opportunity to produce more with less cultivation area, more crop per drop of water, reduction of the toxic chemical load, and improving the ecological footprint. The purpose of this chapter is to highlight the impact of climate change on food security and nutrition security and how soilless cultivation technology can bring a paradigm shift to close the gap between food and nutrition security.

Pathogens are a major threat of plant-based production. Expanding restrictions for the use of classical pesticides is increasing the need of alternative applications to control plant diseases. Nanoparticles have recently received increasing research interest as a potential means to protect plants from adverse conditions including pathogen attack. To assess the beneficial potential of silver nanoparticles to protect plants against the bacterial pathogen Pseudomonas syringae, of which numerous economically relevant pathovars are known, we evaluated the effect of silver nanoparticle pre-treatment in the model pathosystem Arabidopsis thaliana–P. syringae. For this purpose, A. thaliana leaves were treated with different silver nanoparticle concentrations prior to P. syringae infection and visible alterations of the leaf tissue in relation to the individual and combined treatments were scored. While treatment with silver nanoparticles in the concentration range between 0.5 and 10 ppm suppressed P. syringae symptom development, concentrations above 5 ppm caused necroses and chloroses in a dose-dependent manner. This indicates that silver nanoparticles affect plant physiological processes related to cell and tissue integrity that are also associated with the development of infection symptoms caused by P. syringae. Therefore, silver nanoparticle treatments in a suitable concentration range support the maintenance of tissue integrity during pathogen infection in combination with their antimicrobial activity, thus preventing loss of biomass. This makes silver nanoparticles a promising tool for integrative crop protection strategies in commercial production.

Smart sensors are useful in professional farming approach by which one can use the digital technology to monitor, visualize, generate digital data, to control the application of resources, to improve quality and productivity of agriculture produce. Novel sensors add value in soil-less farming through automation and IoT (Internet of Things) based operation management digital tools. Data-driven technologies by using smart sensors can find a solution to many glitches in agriculture practices and it could improve new efficiencies. The principles of smart sensors as well as the most viable sensors that are used for monitoring soil and plant physicochemical parameters in field cultivation processes, greenhouse and indoor hydroponics are being discussed. Digital technologies in precision farming, automation in agro machinery, Precision Livestock Farming (PLF), TV White Spaces (TVWS) remote connectivity, Unmanned Aerial Vehicles (UAVs) based imagery, application of IoTs can help farming communities to use resources accurately based on real-time farm data acquired and improve crop yield without any wastage. Smart sensors helps the entire food value chain, the precision to productivity quest of growers and could enable new business models. This article provides a wide understanding of novel smart sensors, wireless sensor network architectures, and applications of these sensors to inculcate sustainable farming practices, value chain traceability and create secured income.

Microalgae cultivation utilizes the energy of sunlight to reduce carbon dioxide (CO2) for producing renewable energy feedstock. The commercial success of the biological fixation of carbon in a consistent manner depends upon the availability of a robust microalgae strain. In the present work, we report the identification of a novel marine Nannochloris sp. through multiparametric photosynthetic evaluation. Detailed photobiological analysis of this strain has revealed a smaller functional antenna, faster relaxation kinetics of non-photochemical quenching, and a high photosynthetic rate with increasing light and temperatures. Furthermore, laboratory scale growth assessment demonstrated a broad range halotolerance of 10–70 parts per thousand (PPT) and high-temperature tolerance up to 45 °C. Such traits led to the translation of biomass productivity potential from the laboratory scale (0.2–3.0 L) to the outdoor 50,000 L raceway pond scale (500-m2) without any pond crashes. The current investigation revealed outdoor single-day peak areal biomass productivity of 43 g m−2 d−1 in summer with an annual (March 2019–February 2020) average productivity of 20 g m−2 d−1 in seawater. From a sustainability perspective, this is the first report of successful round-the-year (> 347 days) multi-season (summer, monsoon, and winter) outdoor cultivation of Nannochloris sp. in broad seawater salinity (1–57 PPT), wide temperature ranges (15–40 °C), and in fluctuating light conditions. Concurrently, outdoor cultivation of this strain demonstrated conducive fatty acid distribution, including increased unsaturated fatty acids in winter. This inherent characteristic might play a role in protecting photosynthesis machinery at low temperatures and in high light stress. Altogether, our marine Nannochloris sp. showed tremendous potential for commercial scale cultivation to produce biofuels, food ingredients, and a sustainable source for vegetarian protein.

The recent outbreak of COVID 19 pandemic caused by SARS-CoV-2 Coronaviruses claimed millions of lives across the globe. Early diagnosis of the infection is crucial to curb the community spread and enforcing strict quarantine procedure. Real time polymerase chain reaction (RT PCR) based diagnosis is considered as gold standard, however, is resource intensive. We, therefore, developed a PCR based efficient and specific diagnosis method for detection of SARS-CoV-2. We analysed over 100 genomes of SARS-CoV-2 and identified unique consensus sequences for designing PCR primers and evaluated them. Finally, we could optimize the one-step multiplex PCR directly from the extracted RNA and specific primers of envelope protein (E), nucleocapsid protein (N), and membrane protein (M) of SARS-CoV-2. The PCR products were visualized either in agarose gel or in Bioanalyzer. This method showed more than 95% accuracy compared to RT PCR tests, and therefore, is applicable in most of academic as well as pathological laboratory.

Viruses have different strategies for infecting their hosts. Fast and acute infections result in the development of severe symptoms and may cause the death of the plant. By contrast, in a persistent interaction, the virus can survive within its host for a long time, inducing only mild symptoms. In this study, we investigated the gene expression changes induced in CymRSV-, crTMV-, and TCV-infected Nicotiana benthamiana and in PVX- and TMV-U1-infected Solanum lycopersicum plants after the systemic spread of the virus by two different high-throughput methods: microarray hybridization or RNA sequencing. Using these techniques, we were able to clearly differentiate between acute and persistent infections. We validated the gene expression changes of selected genes by Northern blot hybridization or by qRT-PCR. We show that, in contrast to persistent infections, the drastic shut-off of housekeeping genes, downregulation of photosynthesis-related transcripts and induction of stress genes are specific outcomes with acute infections. We also show that these changes are not a consequence of host necrosis or the presence of a viral silencing suppressor. Thermal imaging data and chlorophyll fluorescence measurements correlated very well with the molecular changes. We believe that the molecular and physiological changes detected during acute infections mostly contribute to virus symptom development. The observed characteristic physiological changes associated with economically more dangerous acute infections could serve as a basis for the elaboration of remote monitoring systems suitable for detecting developing virus infections in crops. Moreover, as molecular and physiological changes are characteristics of different types of virus lifestyles, this knowledge can support risk assessments of recently described novel viruses.

Photosynthetic phenotyping requires quick characterization of dynamic traits when measuring large plant numbers in a fluctuating environment. Here, we evaluated the light-induced fluorescence transient (LIFT) method for its capacity to yield rapidly fluorometric parameters from 0.6 m distance. The close approximation of LIFT to conventional chlorophyll fluorescence (ChlF) parameters is shown under controlled conditions in spinach leaves and isolated thylakoids when electron transport was impaired by anoxic conditions or chemical inhibitors. The ChlF rise from minimum fluorescence (Fo) to maximum fluorescence induced by fast repetition rate (Fm-FRR) flashes was dominated by reduction of the primary electron acceptor in photosystem II (QA). The subsequent reoxidation of QA- was quantified using the relaxation of ChlF in 0.65 ms (Fr1) and 120 ms (Fr2) phases. Reoxidation efficiency of QA- (Fr1/Fv, where Fv = Fm-FRR - Fo) decreased when electron transport was impaired, while quantum efficiency of photosystem II (Fv/Fm) showed often no significant effect. ChlF relaxations of the LIFT were similar to an independent other method. Under increasing light intensities, Fr2'/Fq' (where Fr2' and Fq' represent Fr2 and Fv in the light-adapted state, respectively) was hardly affected, whereas the operating efficiency of photosystem II (Fq'/Fm') decreased due to non-photochemical quenching. Fm-FRR was significantly lower than the ChlF maximum induced by multiple turnover (Fm-MT) flashes. However, the resulting Fv/Fm and Fq'/Fm' from both flashes were highly correlated. The LIFT method complements Fv/Fm with information about efficiency of electron transport. Measurements in situ and from a distance facilitate application in high-throughput and automated phenotyping.

Designing and developing new biostimulants is a crucial process which requires an accurate testing of the product effects on the morpho-physiological traits of plants and a deep understanding of the mechanism of action of selected products. Product screening approaches using omics technologies have been found to be more efficient and cost effective in finding new biostimulant substances. A screening protocol based on the use of high-throughput phenotyping platform for screening new vegetal-derived protein hydrolysates (PHs) for biostimulant activity followed by a metabolomic analysis to elucidate the mechanism of the most active PHs has been applied on tomato crop. Eight PHs (A-G, I) derived from enzymatic hydrolysis of seed proteins of Leguminosae and Brassicaceae species were foliarly sprayed twice during the trial. A non-ionic surfactant Triton X-100 at 0.1% was also added to the solutions before spraying. A control treatment foliarly sprayed with distilled water containing 0.1% Triton X-100 was also included. Untreated and PH-treated tomato plants were monitored regularly using high-throughput non-invasive imaging technologies. The phenotyping approach we used is based on automated integrative analysis of photosynthetic performance, growth analysis, and color index analysis. The digital biomass of the plants sprayed with PH was generally increased. In particular, the relative growth rate and the growth performance were significantly improved by PHs A and I, respectively, compared to the untreated control plants. Kinetic chlorophyll fluorescence imaging did not allow to differentiate the photosynthetic performance of treated and untreated plants. Finally, MS-based untargeted metabolomics analysis was performed in order to characterize the functional mechanisms of selected PHs. The treatment modulated the multi-layer regulation process that involved the ethylene precursor and polyamines and affected the ROS-mediated signaling pathways. Although further investigation is needed to strengthen our findings, metabolomic data suggest that treated plants experienced a metabolic reprogramming following the application of the tested biostimulants. Nonetheless, our experimental data highlight the potential for combined use of high-throughput phenotyping and metabolomics to facilitate the screening of new substances with biostimulant properties and to provide a morpho-physiological and metabolomic gateway to the mechanisms underlying PHs action on plants.

In the present study we analyzed the responses of wheat to mild salinity and drought with special emphasis on the so far unclarified interaction of these important stress factors by using high-throughput phenotyping approaches. Measurements were performed on 14 genotypes of different geographic origin (Austria, Azerbaijan, and Serbia). The data obtained by non-invasive digital RGB imaging of leaf/shoot area reflect well the differences in total biomass measured at the end of the cultivation period demonstrating that leaf/shoot imaging can be reliably used to predict biomass differences among different cultivars and stress conditions. On the other hand, the leaf/shoot area has only a limited potential to predict grain yield. Comparison of gas exchange parameters with biomass accumulation showed that suppression of CO2 fixation due to stomatal closure is the principal cause behind decreased biomass accumulation under drought, salt and drought plus salt stresses. Correlation between grain yield and dry biomass is tighter when salt- and drought stress occur simultaneously than in the well-watered control, or in the presence of only salinity or drought, showing that natural variation of biomass partitioning to grains is suppressed by severe stress conditions. Comparison of yield data show that higher biomass and grain yield can be expected under salt (and salt plus drought) stress from those cultivars which have high yield parameters when exposed to drought stress alone. However, relative yield tolerance under drought stress is not a good indicator of yield tolerance under salt (and salt plus drought) drought stress. Harvest index of the studied cultivars ranged between 0.38 and 0.57 under well watered conditions and decreased only to a small extent (0.37–0.55) even when total biomass was decreased by 90% under the combined salt plus drought stress. It is concluded that the co-occurrence of mild salinity and drought can induce large biomass and grain yield losses in wheat due to synergistic interaction of these important stress factors. We could also identify wheat cultivars, which show high yield parameters under the combined effects of salinity and drought demonstrating the potential of complex plant phenotyping in breeding for drought and salinity stress tolerance in crop plants.

Plant-derived protein hydrolysates (PHs) are an important category of biostimulants able to increase plant growth and crop yield especially under environmental stress conditions. PHs can be applied as foliar spray or soil drench. Foliar spray is generally applied to achieve a relatively short-term response, whereas soil drench is used when a long-term effect is desired. The aim of the study was to elucidate the biostimulant action of PH application method (foliar spray or substrate drench) on morpho-physiological traits and metabolic profile of tomato grown under limited water availability. An untreated control was also included. A high-throughput image-based phenotyping (HTP) approach was used to non-destructively monitor the crop response under limited water availability (40% of container capacity) in a controlled environment. Moreover, metabolic profile of leaves was determined at the end of the trial. Dry biomass of shoots at the end of the trial was significantly correlated with number of green pixels (R-2 = 0.90) and projected shoot area, respectively. Both drench and foliar treatments had a positive impact on the digital biomass compared to control while the photosynthetic performance of the plants was slightly influenced by treatments. Overall drench application under limited water availability more positively influenced biomass accumulation and metabolic profile than foliar application. Significantly higher transpiration use efficiency was observed with PH-drench applications indicating better stomatal conductance. The mass-spectrometry based metabolomic analysis allowed the identification of distinct biochemical signatures in PH-treated plants. Metabolomic changes involved a wide and organized range of biochemical processes that included, among others, phytohormones (notably a decrease in cytokinins and an accumulation of salicylates) and lipids (including membrane lipids, sterols, and terpenes). From a general perspective, treated tomato plants exhibited an improved tolerance to reactive oxygen species (ROS)-mediated oxidative imbalance. Such capability to cope with oxidative stress might have resulted from a coordinated action of signaling compounds (salicylic acid and hydroxycinnamic amides), radical scavengers such as carotenoids and prenyl quinones, as well as a reduced biosynthesis of tetrapyrrole coproporphyrins.

Biomass productivity of shrub willow plants grown in short rotation system can be improved by genetic means or by innovative cropping technologies. In the present study we analyzed the growth and physiological responses of willow plants to plant biostimulators, such as 1-triacontanol (TRIA), a saturated primary alcohol and seaweed extract (Kelpak(center dot)). Testing a novel approach, we soaked stem cuttings in TRIA or Kelpak solutions for 48 h before plantation. These treatments enlarged height and diameter of stems, furthermore increased stem and leaf weights in comparison to the water control. In agreement with these greenhouse observations, field tests showed statistically significant enhancement in height and diameter of woody stems harvested in winter. Application of 25% Kelpak solution was the most effective in stimulating all traits including stem weight per plant after pre planting treatment of cuttings. In an alternative treatment protocol, Kelpak was applied as foliar treatment or in combination between TRIA (10 mg L-1) treatment of cuttings and foliar spray with Kelpak 1 or 2% solutions in the greenhouse. The green pixel numbers revealed variable degrees of stimulation in shoot growth. These treatments resulted in an increase in stem and leaf weights. Improvement of photosynthetic functions was indicated by more efficient electron transport rates (ETRs) of photosystems. An increased nicotinamide and thiamine contents were detected in the leaves of stimulated plants. The present study can serve as a foundation for additional laboratory and field studies optimizing the application of these stimulators in energy plantations.

The biomass productivity of the energy willow Salix viminalis as a short-rotation woody crop depends on organ structure and functions that are under the control of genome size. Colchicine treatment of axillary buds resulted in a set of autotetraploid S. viminalis var. Energo genotypes (polyploid Energo [PP-E]; 2n = 4x = 76) with variation in the green pixel-based shoot surface area. In cases where increased shoot biomass was observed, it was primarily derived from larger leaf size and wider stem diameter. Autotetraploidy slowed primary growth and increased shoot diameter (a parameter of secondary growth). The duplicated genome size enlarged bark and wood layers in twigs sampled in the field. The PP-E plants developed wider leaves with thicker midrib and enlarged palisade parenchyma cells. Autotetraploid leaves contained significantly increased amounts of active gibberellins, cytokinins, salicylic acid, and jasmonate compared with diploid individuals. Greater net photosynthetic CO2 uptake was detected in leaves of PP-E plants with increased chlorophyll and carotenoid contents. Improved photosynthetic functions in tetraploids were also shown by more efficient electron transport rates of photosystems I and II. Autotetraploidization increased the biomass of the root system of PP-E plants relative to diploids. Sections of tetraploid roots showed thickening with enlarged cortex cells. Elevated amounts of indole acetic acid, active cytokinins, active gibberellin, and salicylic acid were detected in the root tips of these plants. The presented variation in traits of tetraploid willow genotypes provides a basis to use autopolyploidization as a chromosome engineering technique to alter the organ development of energy plants in order to improve biomass productivity.

We report a case study of natural variations and correlations of some photosynthetic parameters, green biomass and grain yield in Cappelle Desprez and Plainsman V winter wheat ( Triticum aestivum L.) cultivars, which are classified as being drought sensitive and tolerant, respectively. We monitored biomass accumulation from secondary leaves in the vegetative phase and grain yield from flag leaves in the grain filling period. Interestingly, we observed higher biomass production, but lower grain yield stability in the sensitive Cappelle cultivar, as compared to the tolerant Plainsman cv. Higher biomass production in the sensitive variety was correlated with enhanced water-use efficiency. Increased cyclic electron flow around PSI was also observed in the Cappelle cv. under drought stress as shown by light intensity dependence of the ratio of maximal quantum yields of Photosystem I and Photosystem II, as well by the plot of the Photosystem I electron transport rate as a function of Photosystem II electron transport rate. Higher CO 2 uptake rate in flag leaves of the drought-stressed Plainsman cv. during grain filling period correlates well with its higher grain yield and prolonged transpiration rate through spikes. The increase in drought factor (DFI) and performance (PI) indices calculated from variable chlorophyll fluorescence parameters of secondary leaves also showed correlation with higher biomass in the Cappelle cultivar during the biomass accumulation period. However, during the grain filling period, DFI and PI parameters of the flag leaves were higher in the tolerant Plainsman V cultivar and showed correlation with grain yield stability. Our results suggest that overall biomass and grain yield may respond differentially to drought stress in different wheat cultivars and therefore phenotyping for green biomass cannot be used as a general approach to predict grain yield. We also conclude that photosynthetic efficiency of flag and secondary leaves is correlated with grain yield and green biomass, respectively. In addition, secondary trait associated mechanisms like delayed senescence and higher water-use efficiency also contribute to biomass stability. Our studies further prove that photosynthetic parameters could be used to characterize environmental stress responses.

Nanoparticles (NPs) are literally and figuratively infiltrating all fields of biological research. They are sophisticated tools that can be customized, either by smart engineering or by the attachment of specific ligands, to match the requirements of a particular task. Through their inherent and functionalized properties they are the basis for new developments while enhancing the efficiency of already existing techniques or rendering methods to be more specific. They provide new approaches for therapeutic applications and brand new platforms for diagnostic processes. In this review we provide an insight into the practical applications of NPs, emphasizing their use in biosensing, bioimaging, biomolecule delivery systems and enzyme immobilization. Since the interest in the interactions of NPs and biological systems is fairly new, we also elaborate on the drawbacks of their practical applications by reporting their potential toxicity in in vitro and in vivo systems.

1 1 2 3 DUPLICATED GENOME REPROGRAMS ENERGY WILLOW GROWTH 4 5 6 7 8 Corresponding author: Dénes Dudits 9 Institute of Plant Biology 10 Biological Research Center, Hungarian Academy of Sciences 11 6726 Szeged, Temesvári kr. 62 Hungary 12 Tel.: 36 62 599-600 13 dudits.denes@brc.mta.hu 14 15 16 17 Research Area: Genes, Development and Evolution 18 19 20 21 Plant Physiology Preview. Published on January 4, 2016, as DOI:10.1104/pp.15.01679

Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress.

Plant growth is affected by various factors. The resistance of the plant to withstand various biotic and abiotic stress factors plays a vital role for its growth and development. In this study, we have characterized the resistance of various wheat cultivars to tan spot disease by the application of imaging techniques (such as: digital photography, chlorophyll fluorescence) under controlled conditions. The increase of the F0 chlorophyll fluorescence indicates the production of free chlorophylls, which may be involved in the defense reaction against the pathogen. The fluorescence data revealed changes of the photosynthetic apparatus at an early stage before the appearance of visual symptoms appeared, which could be used as an easily measurable markers of the infection.