RESUMEN
We address the targeted destruction of Karenia brevis using the algaecide calcium peroxide, in tandem with the flocculation and sinking of the species. The specific aspect of the approach is the incorporation of the algaecide within the floc to rapidly kill K. brevis, thus minimizing escape of cells from the floc and reentry to the water column. CaO2 gradually produces H2O2, which diffuses through cell membranes and induces oxidative stress, leading to cell death via excessive reactive oxygen species (ROS) formation. The effect of varying doses of calcium peroxide on K. brevis cells was measured with pulse amplitude modulated fluorometry and indicated that doses as low as 30 mg/L when integrated into flocs are effective in suppressing photosynthesis. Cell viability assays also indicate that such low levels are sufficient to cause cell death in a 3-6 hour time period. Thus, the proposed technology involving the incorporation of calcium peroxide in a cationic flocculating agent (polyaluminum chloride, PAC) leads to an inexpensive and scalable technology to mitigate harmful algal blooms of K. brevis.
Asunto(s)
Dinoflagelados , Peróxidos , Dinoflagelados/fisiología , Dinoflagelados/efectos de los fármacos , Floculación , Floraciones de Algas Nocivas , Hidróxido de Aluminio/farmacología , Hidróxido de Aluminio/química , Óxidos/farmacología , Peróxido de Hidrógeno , Especies Reactivas de Oxígeno/metabolismo , Fotosíntesis/efectos de los fármacosRESUMEN
Knowledge is scarce to what extent environmental drivers and native symbiotic fungi in soil induce abrupt (short-term), systemic (multiple traits), or specific (a subset of traits) shifts in C3 plants' ecophysiological/mycorrhizal responses. We cultivated an emblematic native C3 species (Capsicum annuum var. glabriusculum, "Chiltepín") to look at how the extreme heat of the Sonoran desert, sunlight regimes (low = 2, intermediate = 15, high = 46 mol m2 d-1) and density of native arbuscular mycorrhizal fungi in soil (low AMF = 1% v/v, high AMF = 100% v/v), drive shifts on mycorrhizal responses through multiple functional traits (106 traits). The warming thresholds were relentlessly harsh even under intensive shade (e.g. superheat maximum thresholds reached ranged between 47-63°C), and several pivotal traits were synergistically driven by AMF (e.g. photosynthetic capacity, biomass gain/allometry, and mycorrhizal colonization traits); whereas concurrently, sunlight regimes promoted most (76%) alterations in functional acclimation traits in the short-term and opposite directions (e.g. survival, phenology, photosynthetic, carbon/nitrogen economy). Multidimensional reduction analysis suggests that the AMF promotes a synergistic impact on plants' phenotypic integration and functional plasticity in response to sunlight regimes; however, complex relationships among traits suggest that phenotypic variation determines the robustness degree of ecophysiological/mycorrhizal phenotypes between/within environments. Photosynthetic canopy surface expansion, Rubisco activity, photosynthetic nitrogen allocation, carbon gain, and differential colonization traits could be central to plants' overall ecophysiological/mycorrhizal fitness strengthening. In conclusion, we found evidence that a strong combined effect among environmental factors in which AMF are key effectors could drive important trade-offs on plants' ecophysiological/mycorrhizal fitness in the short term.
Asunto(s)
Clima Desértico , Micorrizas , Fenotipo , Micorrizas/fisiología , Capsicum/microbiología , Capsicum/fisiología , Capsicum/efectos de la radiación , Fotosíntesis/fisiología , Simbiosis/fisiología , Luz Solar , BiomasaRESUMEN
Graphene oxide (GO) is a novel nanomaterial being applied in different fields, but was less used as foliar fertilizer in agriculture. We conducted a pot experiment to analyze the effects of foliar spraying GO from 0 (control), 50 (T1), 100 (T2), 150 (T3) and 200 mg·L-1 (T4) on the morphogenesis and carbon and nitrogen metabolism of kidney bean plants during the initiation of flowering to clarify the physiological effects of foliar spraying GO. The results showed that dry matter accumulation, the content of photosynthetic pigments, soluble sugars of T1 to T4 treatments, were significantly increased by 40.7%-43.4%, 10.4%-80.7%, 6.4%-9.1% in kidney bean plants compared with CK treatment, respectively. T3 treatment performed the best. Meanwhile, the activities of sucrose phosphate synthase, acid converting enzyme and neutral converting enzyme of T3 and T4 treatments were increased by 25.7%-45.5%, 17.4%-28.6%, and 14.7%-20.1%, and the activities of nitrate reductase, glutamine synthetase, and glutamate synthetase of T2 and T3 treatments were increased by 8.1%-15.2%, 11.5%-25.0%, and 89.7%-93.1%, respectively. In conclusion, foliar spraying of appropriate GO in early flowering stage of kidney bean could increase the content of photosynthetic pigments, improve the level of photosynthetic carbon and nitrogen metabolism, and increase dry matter accumulation. T3 treatment (150 mg·L-1) was the most effective in this study.
Asunto(s)
Carbono , Flores , Grafito , Nitrógeno , Phaseolus , Nitrógeno/metabolismo , Grafito/metabolismo , Carbono/metabolismo , Phaseolus/crecimiento & desarrollo , Phaseolus/metabolismo , Phaseolus/efectos de los fármacos , Flores/metabolismo , Flores/crecimiento & desarrollo , Flores/efectos de los fármacos , Fertilizantes , Fotosíntesis/efectos de los fármacosRESUMEN
The shortage of water resources and the irrational application of nitrogen fertilizer restrict the synergistic enhancement of yield and water- and fertilizer-use efficiencies of wheat in the Huang-Huai-Hai region. In this study, we conducted an experiment following two-factor split zone design with three irrigation levels and four nitrogen application rates. The relative water content of the 0-40 cm soil layer was supplemented to 65% (W1), 75% (W2), and 85% (W3) of field water capacity at the jointing and anthesis stages of wheat. The rates of nitrogen application were 0 (N0), 150 (N1), 180 (N2), and 210 (N3) kg·hm-2. We analyzed the effects of these different managements on post-anthesis photosynthetic matter production, yield, and water- and nitrogen-use efficiencies. The results showed that yield first increased with increases in the levels of irrigation and nitrogen application, peaking under the W2N2 treatment (9103.53 kg·hm-2). However, further increases in water and nitrogen input did not have further enhancement of wheat yield. Under the same nitrogen application condition, compared with W1 treatment, the canopy light interception rate, chlorophyll relative content and actual photochemical efficiency after anthesis increased by 4.5%-6.0%, 19.7%-28.2%, and 7.5%-9.8% in response to the W2 treatment, respectively, without any difference between the W2 and W3 irrigation levels. At the same irrigation level, post-anthesis dry matter accumulation in repose to the N2 treatment increased by 80.1%-88.9% and 16.7%-22.2% compared with N0 and N1 treatments, respectively, without significant difference between the N2 and N3 treatments. Both the irrigation water-use efficiency (IWUE) and the nitrogen partial factor productivity declined with increases in the levels of irrigation and nitrogen application. Under the W1, W2, and W3 treatments, the values obtained for IWUE were 16.23, 11.01, and 7.91 kg·hm-2·m-3, respectively, whereas in response to the N1, N2, and N3 treatments, N partial factor productivity was 50.8%, 48.4%, and 42.5%, respectively. In all, based on soil moisture measurements and assessments of wheat yield and water- and nitrogen-use efficiencies, the optimal water and nitrogen management strategy for enhancing wheat yield in the Huang-Huai-Hai region is supplementation of water content of 0-40 cm soil layer at the jointing and anthesis stages to 75% field capacity combined with the application of 180 kg·hm-2 nitrogen (W2N2). This approach could achieve high yield and efficiency and promote conservation of water and fertilizer.
Asunto(s)
Riego Agrícola , Fertilizantes , Nitrógeno , Fotosíntesis , Triticum , Agua , Triticum/crecimiento & desarrollo , Triticum/metabolismo , Nitrógeno/metabolismo , Agua/metabolismo , Riego Agrícola/métodos , China , BiomasaRESUMEN
A comprehensive understanding of the evolution of soybean climate potential productivity and its response to climate change in Heilongjiang Province can offer reference and basis for further tapping soybean production potential and realizing stable and high yield of soybean in the frigid region. Based on meteorological data from 80 meteorological stations in Heilongjiang Province from 1961 to 2020, we estimated photosynthesis, light temperature, and climate potential productivity of soybean by the stepwise correction method, examined the spatiotemporal variations by spatial interpolation and statistical analysis methods, and analyzed the impact of changes in climate factors such as radiation, temperature, and precipitation on climate potential productivity. The results showed that during the study period, the average values of photosynthesis potential productivity (YQ), light-temperature potential productivity (YT), and climate potential productivity (YW) of soybean in Heilongjiang Province were 7533, 6444, and 3515 kg·hm-2, respectively. The temporal changes of those variables showed significant increasing trends, with increases of 125.9, 182.9, and 116.1 kg·hm-2·(10 a)-1, respectively. For the spatial distribution, YQ, YT, YW were characterized by high values in plains and lower in the mountains, and gradually decreased from southwest to northeast. Compared with that during 1961-1990, the high value zone of YW in period 1991-2020 expanded by 7.1%, and the low value zone decreased by 5.1%. YW showed a significant response to climate change. The potential temperature growth period was extended due to climate warming. The continuous increase in thermal resources, combined with relatively sufficient precipitation, effectively alleviated the negative impact of the decline in light resources on soybean production in Heilongjiang Province. The projected "warm and humid" climate would comprehensively boost climate potential productivity of soybean in Heilongjiang Province.
Asunto(s)
Cambio Climático , Glycine max , Glycine max/crecimiento & desarrollo , China , Fotosíntesis , Biomasa , Ecosistema , TemperaturaRESUMEN
Traditional pastures in temperate regions face limitations such as reduced growth and nutritional quality during the summer season. Plantain (P. lanceolata L.) offers advantages like increased yield and decreased nitrogen losses from grazing ruminants. Effective grazing management is essential for pasture health, and defoliation frequency and intensity play a pivotal role. This study aimed to evaluate plantain's regrowth, yield, and morpho-physiological and chemical responses under different defoliation frequencies and intensities, with the goal of enhancing its management in pastures. The study was conducted in pots within a controlled-environment growth chamber, examining the impact of three defoliation frequencies (based on extended leaf length: 15, 25 and 35 cm) and two defoliation intensities (5 and 8 cm of residual heights) with four replicates (24 pots as experimental units). The variables of interest were morphological characteristics, dry matter (DM) accumulation, herbage chemical composition, growth rate traits, and photosynthetic parameters. Defoliation frequency affected plantain's growth and nutritional composition. More frequent cuts (15 cm) resulted in lower DM yield per cut and lower stem content, while less frequent cuts (35 cm) produced higher values. Defoliation intensity influenced the proportion of leaves and stems in the total DM, with 5 cm cuts favoring leaves. Nutrient content was also affected by defoliation frequency, with less frequent cuts (35 cm) showing lower crude protein concentration and metabolizable energy content but higher neutral detergent fiber and water-soluble carbohydrate concentration. Plantain's growth rate variables were mainly influenced by defoliation frequency, with less frequent cuts promoting faster leaf appearance and growth of new leaves. The basal fluorescence variables and chlorophyll content were affected by cutting frequency, being highest when cut less frequently (35 cm), while no differences were found in the actual quantum efficiency among different defoliation frequencies and intensities. The fraction of light dedicated to non-photochemical quenching was highest when cut less frequently and more intensively. Overall, defoliation at 25 cm of extended leaf length balanced plantain forage quality and regrowth capacity.
Asunto(s)
Hojas de la Planta , Plantago , Plantago/crecimiento & desarrollo , Plantago/fisiología , Plantago/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/metabolismo , Fotosíntesis , Estaciones del AñoRESUMEN
Canopy leaf abundance of Amazon rainforests increases in the dry season but decreases in the wet season, contrary to earlier expectations of water stress adversely affecting plant functions. Drivers of this seasonality, particularly the role of water availability, remain debated. We introduce satellite-based ecophysiological indicators to demonstrate that Amazon rainforests are constrained by water during dry seasons despite light-driven canopy greening. Evidence includes a shifted partitioning of photosynthetically active radiation toward more isoprene emissions and synchronized declines in leaf and xylem water potentials. In addition, we find that convective storms attenuate light-driven ecosystem greening in the late dry season and then reverse to net leaf loss in the wet season, improving rainforest leaf area predictability by 24 to 31%. These findings highlight the susceptibility of Amazon rainforests to increasing risks of drought and windthrow disturbances under warming.
Asunto(s)
Sequías , Bosque Lluvioso , Estaciones del Año , Agua , Agua/metabolismo , Hojas de la Planta , Fotosíntesis , Árboles , Ecosistema , LluviaRESUMEN
Potatoes (Solanum tuberosum L.) are a significant food crop cultivated around the world. Caffeic acid (CA) can enhance plant growth by promoting antioxidant activity and stimulating root development, contributing to overall plant health and vigor. Cobalt sulfate (CoSO4) boosts plant growth by promoting nitrogen (N) fixation, healthier root development, and chlorophyll synthesis, enhancing photosynthesis and overall plant health. Nanoparticle-coated urea (NPCU) improves nutrient uptake, promoting plant growth efficiency and reducing environmental impact. This study investigates the effects of combining CA, CoSO4, and NPCU as amendments on potatoes with and without NPCU. Four treatments, control, 20 µM CA, 0.15 mg/L CoSO4, and 20 µM CA + 0.15 mg/L CoSO4 with and without NPCU, were applied in four replications using a completely randomized design. Results demonstrate that the combination of CA + CoSO4 with NPCU led to an increase in potato stem length (~ 6%), shoot dry weight (~ 15%), root dry weight (~ 9%), and leaf dry weight (~ 49%) compared to the control in nutrient stress. There was a significant rise in chlorophyll a (~ 27%), chlorophyll b (~ 37%), and total chlorophyll (~ 28%) over the control under nutrient stress also showed the potential of CA + CoSO4 with NPCU. In conclusion, the findings suggest that applying CA + CoSO4 with NPCU is a strategy for alleviating potato nutrient stress.
Asunto(s)
Ácidos Cafeicos , Nanopartículas , Solanum tuberosum , Urea , Solanum tuberosum/efectos de los fármacos , Solanum tuberosum/crecimiento & desarrollo , Ácidos Cafeicos/farmacología , Ácidos Cafeicos/química , Urea/farmacología , Nanopartículas/química , Cobalto/farmacología , Cobalto/química , Fotosíntesis/efectos de los fármacos , Clorofila/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Hojas de la Planta/efectos de los fármacosRESUMEN
Climate change-induced drought stress decreases crop productivity, but the application of ß-sitosterol (BS) and biochar (BC) boosts crop growth and yield. A pot experiment was conducted to examine the effects of the alone and combined application of BS and BC on the growth and yield of Phaseolus vulgaris under drought stress. The synergistic application of BS and BC increased plant height (46.9cm), shoot dry weight (6.9g/pot), and root dry weight (2.5g/pot) of P. vulgaris plants under drought stress. The trend of applied treatments for photosynthetic rate remained as BC (15%)Asunto(s)
Carbón Orgánico
, Sequías
, Phaseolus
, Sitoesteroles
, Sitoesteroles/farmacología
, Phaseolus/efectos de los fármacos
, Phaseolus/fisiología
, Phaseolus/crecimiento & desarrollo
, Carbón Orgánico/farmacología
, Valor Nutritivo
, Estrés Fisiológico/efectos de los fármacos
, Fotosíntesis/efectos de los fármacos
, Peróxido de Hidrógeno/metabolismo
, Malondialdehído/metabolismo
, Resistencia a la Sequía
RESUMEN
Background: Gongolaria barbata is a canopy-forming brown macroalga that thrives in the intertidal and subtidal habitats of the warm-temperate Mediterranean Sea, which is particularly exposed to environmental changes due to its peculiar geographical location and exposure to both global and local stressors. Testing whether this species is featured by specific functional, eco-physiological and biochemical traits allowing an efficient use of habitat resources and adaptation to environmental stress, and whether this potential might change with population growth, is essential for predicting the performance of the algae under different environmental abiotic variables (e.g., temperature, nutrient availability, light) and biotic interactions (such as grazing). Methods: Young (juveniles) and adult thalli of G. barbata were sampled in the winter season from the Venice Lagoon, Italy, featured by high environmental changes (temperature, salinity) and analyzed for thallus dry matter content (TDMC), photosynthetic activity, photosynthetic pigment and protein content, and antioxidant capacity to assess if thallus age may be considered a significant driver in determining the ecological responses of this species to environmental changes. Results: Our results showed that TDMC was higher in adults than juveniles. At the functional level, rapid light curves indicated an elevated photosynthetic efficiency in juveniles compared to adults highlighted by the higher quantum yield of PSII electron transport, electron transport rate, and Rubisco content observed in juveniles. On the contrary, adults exhibited a higher non-photochemical quenching and total pigment concentration. No difference in maximum PSII photochemical efficiency and D1 protein content between the two thalli groups was found. Along with better photosynthesis, juveniles also displayed a higher amount of total polyphenols, flavonoids, and tannins, and a stronger antioxidant capacity compared to adults. Conclusions: Our findings revealed significant differences in the eco-physiological characteristics of G. barbata at different growth stages. It was observed that young thalli, allocate more energy to photosynthesis and chemical defenses by increasing the production of antioxidant compounds, such as polyphenols, flavonoids, and tannins. With growth, thalli likely adopt a more conservative strategy, reducing photosynthesis and promoting structural biomass accumulation to mitigate the potential risks associated with prolonged exposure to environmental stressors, such as the wavy way. Although our study focused on a single phase of G. barbata life cycle under winter settings, it offers preliminary insights into this species eco-physiological traits and auto-ecology. Future research could explore the potential implications of these findings, evaluating the species' resilience to environmental changes at the population level.
Asunto(s)
Phaeophyceae , Fotosíntesis , Phaeophyceae/fisiología , Phaeophyceae/metabolismo , Fotosíntesis/fisiología , Ecosistema , Estaciones del Año , Italia , Mar Mediterráneo , Temperatura , Antioxidantes/metabolismo , Algas Marinas/metabolismo , Algas Marinas/fisiología , Algas Marinas/crecimiento & desarrolloRESUMEN
A fundamental assumption in plant science posits that leaf air spaces remain vapor saturated, leading to the predominant view that stomata alone control leaf water loss. This concept has been pivotal in photosynthesis and water-use efficiency research. However, recent evidence has refuted this longstanding assumption by providing evidence of unsaturation in the leaf air space of C3 plants under relatively mild vapor pressure deficit (VPD) stress. This phenomenon represents a nonstomatal mechanism restricting water loss from the mesophyll. The potential ubiquity and physiological implications of this phenomenon, its driving mechanisms in different plant species and habitats, and its interaction with other ecological adaptations have. In this context, C4 plants spark particular interest for their importance as crops, bundle sheath cells' unique anatomical characteristics and specialized functions, and notably higher water-use efficiency relative to C3 plants. Here, we confirm reduced relative humidities in the substomatal cavity of the C4 plants maize, sorghum, and proso millet down to 80% under mild VPD stress. We demonstrate the critical role of nonstomatal control in these plants, indicating that the role of the CO2 concentration mechanism in CO2 management at a high VPD may have been overestimated. Our findings offer a mechanistic reconciliation between discrepancies in CO2 and VPD responses reported in C4 species. They also reveal that nonstomatal control is integral to maintaining an advantageous microclimate of relatively higher CO2 concentrations in the mesophyll air space of C4 plants for carbon fixation, proving vital when these plants face VPD stress.
Asunto(s)
Células del Mesófilo , Fotosíntesis , Presión de Vapor , Zea mays , Células del Mesófilo/metabolismo , Zea mays/fisiología , Zea mays/metabolismo , Fotosíntesis/fisiología , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Agua/metabolismo , Estrés Fisiológico/fisiología , Dióxido de Carbono/metabolismo , Sorghum/metabolismo , Sorghum/fisiología , Estomas de Plantas/fisiología , Estomas de Plantas/metabolismoRESUMEN
Our study attempts to address the following questions: among numerous photosynthetic modules, which parameters notably influence the rapid chlorophyll fluorescence (ChlF) rise, the so-called O-J-I-P transient, in conjunction with the P515 signal, as these two records are easily obtained and widely used in photosynthesis research, and how are these parameters ranked in terms of their importance? These questions might be difficult to answer solely through experimental assays. Therefore, we employed an established photosynthesis model. Firstly, we utilized the model to simulate the measured rapid ChlF rise and P515 kinetics simultaneously. Secondly, we employed the sensitivity analysis (SA) tool by randomly altering model parameters to observe their effects on model output variables. Thirdly, we systematically identified significant parameters for both or one of the kinetics across various scenarios. A novel aspect of our study is the application of the Morris method, a global SA tool, to simultaneously assess the significance of model parameters in shaping both or one of the kinetics. The Morris SA technique enables the quantification of how much a specific parameter affects O-J-I-P transient during particular time intervals (e.g., J, I, and P steps). This allowed us to theoretically analyze which step is more significantly influenced by the parameter. In summary, our study contributes to the field by providing a comprehensive analysis of photosynthesis kinetics and emphasizing the importance of parameter selection in modelling this process. These findings can inform future research efforts aimed at improving photosynthesis models and advancing our understanding of photosynthetic processes.
Asunto(s)
Clorofila A , Fotosíntesis , Tilacoides , Cinética , Fluorescencia , Clorofila A/metabolismo , Fotosíntesis/fisiología , Tilacoides/metabolismo , Clorofila/metabolismo , Modelos BiológicosRESUMEN
Water-saving and drought-resistant rice (WDR) coupled with alternate wetting and drying irrigation (AWDI) possesses a high photosynthetic potential due to higher mesophyll conductance (gm) under drought conditions. However, the physiological and structural contributions to the gm of leaves and their mechanisms in WDR under AWDI are still unclear. In this study, WDR (Hanyou 73) and drought-sensitive rice (Huiliangyou 898) were selected as materials. Three irrigation patterns were established from transplanting to the heading stage, including conventional flooding irrigation (W1), moderate AWDI (W2), and severe AWDI (W3). A severe drought with a soil water potential of -50 kPa was applied for a week at the heading stage across all treatments and cultivars. The results revealed that severe drought reduced gas exchange parameters and gm but enhanced antioxidant enzyme activities and malondialdehyde content in the three treatments and both cultivars. The maximal photosynthetic rate (Amax) of HY73 in the W2 treatment was greater than that in the other combinations of cultivars and irrigation patterns. The contribution of leaf structure (54%) to gm (gm-S, structural gm) was higher than that of leaf physiology (46%) to gm (gm-P, physiological gm) in the W2 treatment of Hanyou 73. Additionally, gm-S was significantly and linearly positively correlated with gm under severe drought. Moreover, both the initial and apparent quantum efficiencies were significantly and positively with gm in rice plants (p < 0.05). These results suggest that the improvements in photosynthesis and yield in the WDR combined with moderate AWDI can mainly be attributed to the enhancement of gm-S under severe drought conditions. Quantum efficiency may be a potential factor in regulating photosynthesis by cooperating with the gm of rice plants under severe drought conditions.
Asunto(s)
Riego Agrícola , Sequías , Células del Mesófilo , Oryza , Fotosíntesis , Hojas de la Planta , Agua , Oryza/fisiología , Agua/metabolismo , Riego Agrícola/métodos , Fotosíntesis/fisiología , Células del Mesófilo/fisiología , Hojas de la Planta/fisiología , Transpiración de Plantas/fisiología , Desecación/métodosRESUMEN
Biofuel can be generated by different organisms using various substrates. The green alga Chlorococcum humicola OQ934050 exhibited the capability to photosynthesize carbonate carbon, maybe via the activity of carbonic anhydrase enzymes. The optimum treatment is C:N ratio of 1:1 (0.2 mmoles sodium carbonate and 0.2 mmoles sodium nitrate) as it induced the highest dry mass (more than 0.5 mg.mL-1). At this combination, biomass were about 0.2 mg/mL-1 carbohydrates, 0.085 mg/mL-1 proteins, and 0.16 mg/mL-1 oil of this dry weight. The C/N ratios of 1:1 or 10:1 induced up to 30% of the Chlorococcum humicola dry mass as oils. Growth and dry matter content were hindered at 50:1 C/N and oil content was reduced as a result. The fatty acid profile was strongly altered by the applied C.N ratios. The defatted leftovers of the grown alga, after oil extraction, were fermented by a newly isolated heterotrophic bacterium, identified as Bacillus coagulans OQ053202, to evolve hydrogen content as gas. The highest cumulative hydrogen production and reducing sugar (70 ml H2/g biomass and 0.128 mg/ml; respectively) were found at the C/N ratio of 10:1 with the highest hydrogen evolution efficiency (HEE) of 22.8 ml H2/ mg reducing sugar. The optimum treatment applied to the Chlorococcum humicola is C:N ratio of 1:1 for the highest dry mass, up to 30% dry mass as oils. Some fatty acids were induced while others disappeared, depending on the C/N ratios. The highest cumulative hydrogen production and reducing sugar were found at the C/N ratio of 10:1.
Asunto(s)
Bacillus , Biocombustibles , Biomasa , Carbonatos , Hidrógeno , Nitratos , Hidrógeno/metabolismo , Bacillus/metabolismo , Nitratos/metabolismo , Carbonatos/metabolismo , Fermentación , Chlorophyta/metabolismo , Chlorophyta/crecimiento & desarrollo , Fotosíntesis , Ácidos Grasos/metabolismoRESUMEN
INTRODUCTION: The effects of salinity memory and its interaction with genetic diversity for drought tolerance and pollination system in terms of morphological, physiological, root characteristics and spectral reflectance indices (SRIs) in tall fescue is still unknown. METHODS: Four tall fescue genotypes (two drought-sensitive and two drought-tolerant) were manually controlled to produce four selfed (S1) and four open-pollinated (OP) progeny genotypes (finally eight progeny genotypes). Then all genotypes were assessed for two years in greenhouse under five salinity treatments including control treatment (C), twice salinity stress treatment (primary mild salinity stress in two different stages and secondary at the end stage) (S1t1S2 and S1t2S2), once severe salinity stress treatment (secondary only, S2), and foliar spray of salicylic acid (SA) simultaneously with secondary salinity stress (H2S2). RESULTS: Results indicated that obligate selfing (S1) caused to inbreeding depression in RWC, plant growth, catalase activity, root length and the ratio of root/shoot (R/S). Once salinity stress treatment (S2) led to depression in most measured traits, while pre-exposure to salinity (salinity memory) (S1t1S2 and S1t2S2) improved photosynthetic pigments, proline, antioxidant enzymes and R/S. CONCLUSION: Salinity memory was more pronounced in drought-sensitive genotypes, while it was more evident in OP than S1 population. Foliar spray of salicylic acid (SA) was almost equally effective in reducing the effects of salinity stress in both populations. The efficacy of application was more pronounced in tolerant genotypes compared to sensitive ones. The possibility of modeling correlated spectral reflectance indices (SRIs) for prediction of different morphological, physiological and root characteristics will be discussed.
Asunto(s)
Festuca , Variación Genética , Polinización , Estrés Salino , Festuca/genética , Festuca/fisiología , Genotipo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/efectos de los fármacos , Sequías , Fotosíntesis/efectos de los fármacos , Salinidad , Estrés FisiológicoRESUMEN
Biogenic secondary organic aerosols (SOAs) can be formed from the oxidation of plant volatiles in the atmosphere. Herbivore-induced plant volatiles (HIPVs) can elicit plant defenses, but whether such ecological functions persist after they form SOAs was previously unknown. Here we show that Scots pine seedlings damaged by large pine weevils feeding on their roots release HIPVs that trigger defenses in neighboring conspecific plants. The biological activity persisted after HIPVs had been oxidized to form SOAs, which was indicated by receivers displaying enhanced photosynthesis, primed volatile defenses, and reduced weevil damage. The elemental composition and quantity of SOAs likely determines their biological functions. This work demonstrates that plant-derived SOAs can mediate interactions between plants, highlighting their ecological significance in ecosystems.
Asunto(s)
Aerosoles , Herbivoria , Raíces de Plantas , Compuestos Orgánicos Volátiles , Gorgojos , Animales , Compuestos Orgánicos Volátiles/metabolismo , Gorgojos/fisiología , Raíces de Plantas/metabolismo , Pinus sylvestris/metabolismo , Plantones/metabolismo , Oxidación-Reducción , Fotosíntesis , Defensa de la Planta contra la HerbivoriaRESUMEN
Synechococcus elongatus is an important cyanobacterium that serves as a versatile and robust model for studying circadian biology and photosynthetic metabolism. Its transcriptional regulatory network (TRN) is of fundamental interest, as it orchestrates the cell's adaptation to the environment, including its response to sunlight. Despite the previous characterization of constituent parts of the S. elongatus TRN, a comprehensive layout of its topology remains to be established. Here, we decomposed a compendium of 300 high-quality RNA sequencing datasets of the model strain PCC 7942 using independent component analysis. We obtained 57 independently modulated gene sets, or iModulons, that explain 67% of the variance in the transcriptional response and 1) accurately reflect the activity of known transcriptional regulations, 2) capture functional components of photosynthesis, 3) provide hypotheses for regulon structures and functional annotations of poorly characterized genes, and 4) describe the transcriptional shifts under dynamic light conditions. This transcriptome-wide analysis of S. elongatus provides a quantitative reconstruction of the TRN and presents a knowledge base that can guide future investigations. Our systems-level analysis also provides a global TRN structure for S. elongatus PCC 7942.
Asunto(s)
Ritmo Circadiano , Regulación Bacteriana de la Expresión Génica , Redes Reguladoras de Genes , Aprendizaje Automático , Synechococcus , Synechococcus/genética , Synechococcus/metabolismo , Ritmo Circadiano/genética , Ritmo Circadiano/fisiología , Fotosíntesis/genética , Transcriptoma , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismoRESUMEN
Wheat is an important staple crop not only in Pakistan but all over the globe. Although the area dedicated to wheat cultivation expands annually, the quantity of wheat harvested is declining due to various biotic and abiotic factors. Global wheat production and output have suffered as a result of the drought, which is largely driven by a lack of water and environmental factors. Organic fertilizers have been shown to reduce the severity of drought. The current research was conducted in semi-arid climates to mitigate the negative effects of drought on wheat during its critical tillering (DTS), flowering (DFS), and grain filling (DGFS) stages through the application of three different abscisic acid treatments: ABA0 (0 mgL-1) control, ABA1 (100 mgL-1) and ABA2 (200 mgL-1). Wheat growth and yield characteristics were severely harmed by drought stress across all critical development stages, with the DGFS stage being particularly vulnerable and leading to a considerable loss in yield. Plant height was increased by 24.25%, the number of fertile tillers by 25.66%, spike length by 17.24%, the number of spikelets per spike by 16.68%, grain count per spike by 11.98%, thousand-grain weight by 14.34%, grain yield by 26.93% and biological yield by 14.55% when abscisic acid (ABA) was applied instead of the control treatment. Moreover, ABA2 increased the more physiological indices (water use efficiency (36.12%), stomatal conductance (44.23%), chlorophyll a (24.5%), chlorophyll b (29.8%), transpiration rate (23.03%), photosynthetic rate (24.84%), electrolyte leakage (- 38.76%) hydrogen peroxide (- 18.09%) superoxide dismutase (15.3%), catalase (20.8%), peroxidase (- 18.09%), and malondialdehyde (- 13.7%)) of drought-stressed wheat as compared to other treatments. In the case of N, P, and K contents in grain were maximally improved with the application of ABA2. Through the use of principal component analysis, we were able to correlate our results across scales and provide an explanation for the observed effects of ABA on wheat growth and production under arid conditions. Overall, ABA application at a rate of 200 mgL-1 is an effective technique to boost wheat grain output by mitigating the negative effects of drought stress.
Asunto(s)
Ácido Abscísico , Sequías , Triticum , Ácido Abscísico/metabolismo , Triticum/crecimiento & desarrollo , Triticum/efectos de los fármacos , Triticum/metabolismo , Triticum/fisiología , Clorofila/metabolismo , Estrés Fisiológico , Fotosíntesis/efectos de los fármacos , Reguladores del Crecimiento de las Plantas/metabolismo , Reguladores del Crecimiento de las Plantas/farmacologíaRESUMEN
To analyse the effect of nutrient management on the growth, physiology, energy utilization, production and quality of black gram, a field trial on black gram was conducted at eastern Indian Gangetic alluvium during the autumn of 2020 and 2021. Treatments were two soil applications of cobalt (Co) and foliar spray of potassium (K) and boron (B) in five combinations. All treatments were arranged in a split-plot design and repeated three times. Two soil applications of cobalt (Co) were assigned in the main plots and foliar spray of potassium (K) and boron (B) in five combinations were assigned in sub-plots. Applications of Co in soil and foliar K+B facilitated significantly higher (p≤0.05) values for aerial dry matter (ADM), leaf area index (LAI), nodules per plant, total chlorophyll, net photosynthetic rate and nitrate reductase content in both 2020 and 2021, with a greater realization of photosynthetically active radiation interception, and use efficiency (IPAR and PARUE respectively), seed yield, seed nutrients and protein contents. Differences in LAI exhibited positive and linear correlation with IPAR explaining more than 60% variations in different growth stages. The innovative combination of soil Co (beneficial nutrient) application at 4 kg ha-1 combined with foliar 1.25% K (macronutrient) + 0.2% B (micronutrient) spray is a potential agronomic management schedule for the farmers to sustain optimum production of autumn black gram through substantial upgradation of growth, physiology, energy utilization, production and quality in Indian subtropics.
Asunto(s)
Fotosíntesis , Potasio , Estaciones del Año , Suelo , Vigna , Potasio/metabolismo , Potasio/análisis , Vigna/crecimiento & desarrollo , Vigna/metabolismo , Suelo/química , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Boro/metabolismo , Cobalto , Nutrientes/metabolismo , Clorofila/metabolismo , Fertilizantes , India , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Semillas/efectos de la radiaciónRESUMEN
Photosynthesis is one of the most important biological processes on Earth, providing the main source of bioavailable energy, carbon, and oxygen via the use of sunlight. Despite this importance, the minimum light level sustaining photosynthesis and net growth of primary producers in the global ocean is still unknown. Here, we present measurements from the MOSAiC field campaign in the central Arctic Ocean that reveal the resumption of photosynthetic growth and algal biomass buildup under the ice pack at a daily average irradiance of not more than 0.04 ± 0.02 µmol photons m-2 s-1 in late March. This is at least one order of magnitude lower than previous estimates (0.3-5 µmol photons m-2 s-1) and near the theoretical minimum light requirement of photosynthesis (0.01 µmol photons m-2 s-1). Our findings are based on measurements of the temporal development of the under-ice light field and concurrent measurements of both chlorophyll a concentrations and potential net primary production underneath the sea ice at 86 °N. Such low light requirements suggest that euphotic zones where photosynthesis can occur in the world's oceans may extend further in depth and time, with major implications for global productivity estimates.