Vegetative Cycle Research Articles

UHPLC-HRMS profile and accumulation of argentatins in stems of 27 accessions of guayule (Parthenium argentatum A. Gray) and its hybrids along the growth cycle

The argentatins are the most abundant compounds in guayule resin with promising potential for the biopharmaceutical industry. However, their accumulation along the vegetative cycle of the plant and their quantification in different guayule accessions has not been assessed. The present study established the profile of 16 known compounds of the argentatin family in 27 guayule and guayule interspecific accessions using UHPLC-Q-Orbitrap-HRMS. In addition, the structure of five unreported argentatins was tentatively identified. All compounds were present in all accessions (27) and samples (135) analyzed, although in varying amounts. Those compounds found in the highest proportion were argentatins A, B, C, G, isoargentatin A, 16-dehydroargentatin C and quisquagenin. The mass spectra of the compounds were more complex than expected, revealing the lability of the compounds and a high probability to partially degrade during analysis, even at the mildest ionization energies. Based on available standards, argentatins A and B and isoargentatins A and B were quantified in 27 accessions and five samplings along the growing season. The total abundance of the four compounds was 13.4–39.6% of the guayule resin in stems depending on the accession. The profiles of accumulation were related to the genetic origin, with the summer and spring periods producing the greatest yield of argentatins. Pure guayule accessions generally produced more argentatins than hybrids, although the most productive for argentatins and isoargentatins A and B was the non-mariola hybrid AZ-3. • Twenty-one argentatins and related compounds were found in 27 guayule accessions. • Major compounds were argentatins A, B, C, G, isoargentatin A and 16-dehydroargentatin C. • The argentatins profile of accumulation was related to the genetic origin. • Pure guayule accessions produced more argentatins than hybrids. • Four compounds’ account for 13.4–39.6% of the resin depending on the accession.

Spatial-Temporal Relationship Analysis of Vegetation Phenology and Meteorological Parameters in an Agro-Pasture Ecotone in China

Vegetation phenology is a sensitive indicator of climate change, and can help understand the response of vegetation cycles to climate, which is important for understanding the impact of global climate change on terrestrial ecosystems. In this study, based on the enhanced vegetation index (EVI) time-series data, derived from the moderate-resolution imaging spectroradiometer (MODIS) data, the climate parameters were extracted using the Savitzky–Golay (S–G) filtering method to explore the spatial and temporal variation characteristics of the vegetation phenology in an agro-pasture ecotone in China, from 2000 to 2020. In addition, the response characteristics of the vegetation phenology to the climate elements (temperature and precipitation) were also analyzed. The results showed the following: (1) The start of the growing season (SOS) was widely advanced, and that was caused by climate change. The end of the growing season (EOS) was delayed, and the length of the growing season (LOS) was gradually extended with a large interannual fluctuation in the SOS and the LOS in the region; (2) the SOS showed significant negative correlations with the air temperature and precipitation. Precipitation was mainly positively correlated with the EOS, but there was no significant difference in the correlation between temperature and the EOS. In general, pre-season precipitation is the main driver of the vegetation phenology, while the influence of temperature on the phenology is less obvious; (3) in the semi-arid area and arid area, the phenology was mainly influenced by precipitation. The response of the vegetation phenology to the temperatures in different temperature zones was found to be regular, showing high spatial differences. In general, the higher the cumulus temperature, the lower the negative effect of the temperature on both the SOS and EOS. These results may provide new reference to study the non-systematic changes of the vegetation phenology in response to climate change.

A divide-and-conquer approach for genomic prediction in rubber tree using machine learning

Rubber tree (Hevea brasiliensis) is the main feedstock for commercial rubber; however, its long vegetative cycle has hindered the development of more productive varieties via breeding programs. With the availability of H. brasiliensis genomic data, several linkage maps with associated quantitative trait loci have been constructed and suggested as a tool for marker-assisted selection. Nonetheless, novel genomic strategies are still needed, and genomic selection (GS) may facilitate rubber tree breeding programs aimed at reducing the required cycles for performance assessment. Even though such a methodology has already been shown to be a promising tool for rubber tree breeding, increased model predictive capabilities and practical application are still needed. Here, we developed a novel machine learning-based approach for predicting rubber tree stem circumference based on molecular markers. Through a divide-and-conquer strategy, we propose a neural network prediction system with two stages: (1) subpopulation prediction and (2) phenotype estimation. This approach yielded higher accuracies than traditional statistical models in a single-environment scenario. By delivering large accuracy improvements, our methodology represents a powerful tool for use in Hevea GS strategies. Therefore, the incorporation of machine learning techniques into rubber tree GS represents an opportunity to build more robust models and optimize Hevea breeding programs.

Bamboo and rattan: Nature-based solutions for sustainable development

Bamboo and rattan: Nature-based solutions for sustainable development

Potato Aeroponics: Effects of Cultivar and Plant Origin on Minituber Production

Aeroponics is a modern and soilless technology that is used for the efficient production of pre-basic seed potatoes, namely minitubers. This study aimed to evaluate the effects of the cultivar and type of planting material on the production of minitubers in the aeroponic facility in Guča, Serbia, at short, 7-day harvest intervals. Although aeroponic cultivation prolonged the vegetative cycle in all five investigated cultivars, the dynamics of minituber formation varied between genotypes. Two early maturing cultivars, Cleopatra and Sinora, quickly completed the vegetative cycle and formed a small number of minitubers, while the medium-late to late cultivars, Kennebec and Agria, steadily tuberized during the entire cultivation period in the aeroponic facility. The type of planting material affected the dynamics of minituber formation in three investigated cultivars. Sinora, Cleopatra, and Désirée’s plants of in vitro origin reached the final number of minitubers and the vines started senescing much earlier than plants of minituber origin. Kennebec and Agria plants of in vitro origin produced the largest number of minitubers (53.8–54.5) and showed the highest yield (9.8–10.5 kg m−2) during the cultivation period, while the heaviest minitubers were formed by Sinora plants of minituber origin (15.48 g). In addition, the temperature during pre-harvest periods significantly affected the number of tubers at harvests in Kennebec and Agria, and minituber mass in Désirée.

Genome-wide identification and analysis of the cytokinin oxidase/dehydrogenase (ckx) gene family in finger millet (Eleusine coracana).

Cytokinin dehydrogenase/oxidase (CKX) enzymes play a key role in regulating cytokinin (CK) levels in plants by degrading the excess of this phytohormone. CKX genes have proven an attractive target for genetic engineering, as their silencing boosts cytokinin accumulation in various tissues, thereby contributing to a rapid increase in biomass and overall plant productivity. We previously reported a similar effect in finger millet (Eleusine coracana) somaclonal lines, caused by downregulation of EcCKX1 and EcCKX2. However, the CKX gene family has numerous representatives, especially in allopolyploid crop species, such as E. coracana. To date, the entire CKX gene family of E. coracana and its related species has not been characterized. We offer here, for the first time, a comprehensive genome-wide identification and analysis of a panel of CKX genes in finger millet. The functional genes identified in the E. coracana genome are compared with the previously-identified genes, EcCKX1 and EcCKX2. Exon-intron structural analysis and motif analysis of FAD- and CK-binding domains are performed. The phylogeny of the EcCKX genes suggests that CKX genes are divided into several distinct groups, corresponding to certain isotypes. Finally, the phenotypic effect of EcCKX1 and EcCKX2 in partially silencing the SE7 somaclonal line is investigated, showing that lines deficient in CKX-expression demonstrate increased grain yield and greater bushiness, enhanced biomass accumulation, and a shorter vegetation cycle.

Effect of Deficit Irrigation on Yield Components and Chemical Composition of Albariño Grapes Grown in Galicia, NW Spain

In the context of climate change, water management is crucial for controlling the reproductive growth and quality of grapes. In this study, we aim to determine the effects of different water regimes on the yield components and chemical composition of grape Vitis vinifera Albariño grown in Galicia. Four treatments were tested in the trial: rainfed (T0), irrigated at 30% of ETo from veraison to harvest (T1), from pea-size to harvest (T2), and throughout the whole vegetative cycle (T6). To analyse the effects of irrigation, measures of stem water potential (Ψstem) were obtained fortnightly, from flowering to harvest. During the harvest, the average weight per bunch and the number of bunch and yield per vine were determined. In addition, the Ravaz index was also calculated. The grapes from each experimental treatment were subjected to chemical (OIV methods) and volatile composition (GC-MS) analyses. The results indicated a greater yield in the T0 group. The lowest yield was observed for T2 over the three years of the study. The results also showed a stronger influence of year than treatment on Albariño must include chemical composition parameters. Treatment affected malic acid, total acidity, free amino acids (FAN), and assimilable yeast nitrogen (YAN); meanwhile, of the volatile chemical groups analysed, esters, acetates, and volatile acids were affected by the treatment, while the season affected all chemical families of volatile compounds, with the exception of C6 compounds. The interaction effect of Tr × Y was observed on esters, acetates, and total volatile concentration. In the contrast analysis (p < 0.05), we observed increases in alcohols and terpenes in T6 vs. T2; however, esters and acetates were increased under rainfed treatment (T0) vs. T6.

Effect of Sheep Grazing, Stocking Rates and Dolomitic Limestone Application on the Floristic Composition of a Permanent Dryland Pasture, in the Montado Agroforestry System of Southern Portugal.

Simple SummaryThe Montado is a characteristic ecosystem of the Mediterranean region, where agricultural activities, animal production and forestry coexist alongside tourism, hunting and leisure activities. Animal grazing is fundamental for the conservation of the Montado, and it is imperative to clearly understand its interactions with the pasture floristic composition (PFC) of the Montado. The objective of this study was to evaluate the effect of sheep grazing, stocking rates and dolomitic limestone application on the floristic composition of permanent dryland pastures, in the Montado agroforestry system of Southern Portugal. The type of grazing influences the PFC, which may be positively or negatively impacted, depending on the adopted system. Deferred grazing seems to benefit the disappearance of undesirable plants and the appearance of desired plants. The results of this study allow for more informed management decisions and a potential increase in animal production but also improve the knowledge of conservation strategies in the Montado.The Montado is a complex agroforestry–pastoral ecosystem due to the interactions between soil–pasture–trees–animals and climate. The typical Montado soil has an acidic pH and manganese toxicity, which affect the pasture’s productivity and pasture floristic composition (PFC). The PFC, on the other hand, can also be influenced by the type and intensity of grazing, which can lead to significant decreases in the amount of biomass produced and the biodiversity of species in the pasture. The objective of this study was to evaluate the effect of grazing type, by sheep, and different stocking rates on the PFC throughout the vegetative pasture cycle in areas with and without dolomitic limestone application. Thus, four treatments (P1UC to P4TC) were constituted: P1UC—without limestone application (U) and continuous grazing (CG); P2UD—U and deferred grazing (DG); P3TD—with the application of limestone (T) and DG; P4TC—T and CG. In DG plots, the placement and removal of the animals were carried out as a function of the average height of the pasture (placement—10 cm; removal—3 to 5 cm). The PFC was characterized in winter, at the peak of spring and in late spring. The PFC data were subjected to a multilevel pattern analysis (ISA). The combination of rainfall and temperature influenced the pasture growth rates and consequently the height of the pasture at different times of the year. Therefore, with the different growth rates of the pasture throughout the year, the sheep remain for different periods of time in the deferred grazing treatments. In the four treatments, 103 plant species were identified. The most representative botanical families in the four treatments were Asteraceae, Fabaceae and Poaceae. ISA identified 14 bioindicator species: eight for the winter period, three for the late spring vegetative period and three for the TC treatment.

Spatio-temporally varying Strickler coefficient: A calibration approach applied to a Danish river using in-situ water surface elevation and UAS altimetry

Hydraulic roughness (e.g., expressed in terms of Manning’s or Strickler’s coefficient) is an essential input to numerical hydrodynamic models. One way to estimate roughness parameters is by hydraulic inversion, using observed water surface elevation (WSE) collected from gauging stations, satellite platforms, or Unmanned Aerial System (UAS) altimeters. Specifically, UAS altimetry provides close to instantaneous observations of longitudinal profiles and seasonal variations of WSE for various river types, which are helpful for calibrating roughness parameters. However, it is computationally expensive to run high-resolution hydrodynamic models thousands to millions of times as required for the global optimization of distributed parameter sets (e.g., spatio-temporally varying river roughness).This study presents an efficient calibration approach for hydrodynamic models using a simplified steady-state hydraulic solver, UAS altimetry datasets, and in-situ observations. The calibration approach minimized the weighted sum of a misfit term, spatial smoothness penalty, and an a-priori sinusoidal temporal variation constraint. The approach was first demonstrated for several synthetic calibration experiments, and the results indicated that the global search algorithm accurately recovered the variations of Strickler coefficient (Ks) for short river reaches in temporal (due to the seasonal growth cycle of the aquatic vegetation) and spatial (e.g., due to spatially variable density of submerged vegetation) scales. Subsequently, the calibration approach was demonstrated for a real WSE dataset collected at a Danish test site (Vejle Å). In this river, friction is dominated by submerged vegetation growing in the stream and shows strong seasonal and longitudinal variations due to the plant growth cycle and variable vegetation density and species composition. Results indicated that spatio-temporal variation of Ks was required to fit in-situ observations and UAS altimetry accurately. This study illustrates how UAS altimetry and hydrodynamic modeling can be combined to achieve an improved understanding and better parameterization of small and medium-sized rivers, where river channel conveyance is controlled by vegetation growth and other spatio-temporally variable factors.

Effect of Parental Components and Pollination Frequency on the Setting and Germination of Chrysanthemum Seeds

The chrysanthemum is one of the most economically important ornamental plants in the Asteraceae family. Unfortunately, the efficacy of breeding through the traditional crossing in this species is highly limited due to inefficient seed setting. Therefore, this study aimed to investigate the effect of parental components and crossing frequency on the set and germination of chrysanthemum seeds. For this purpose, seven chrysanthemum cultivars were used as parental components in 10 crossing combinations. The crossing was performed either once or twice a week, for three successive weeks, starting from November. Next, the obtained chrysanthemum seeds were collected, sown in pots in a greenhouse, and seedling growth was observed. The efficacy of the seed set, germination rate, and plant development was evaluated. The plants of the F1 generation were brought to flowering and evaluated phenotypically in the three successive vegetative propagation cycles. Both the arrangement of parental components and pollination frequency affected the production of seeds. More seeds were obtained if pollination was performed twice a week and if the ‘Wda’ cultivar was used as the maternal component. Approximately 50–100% of the seeds were able to germinate in the greenhouse, depending on the parental components, which also affected the developmental pace of the seedlings. Nearly all of the seedlings (80–100%) developed into properly growing plants. Out of 10 parental combinations tested, 7 produced the F1 offspring. The obtained plants varied in the shape, size, and color of their flowers. A total of eight new phenotypes were found, among which six new cultivars granted plant breeders’ rights, so far. The present research expands knowledge on how effective crossing should be performed.

Ecological groups and isotopic niches of earthworms

Earthworms are generally categorized into three ecological groups. This categorization and its two refined versions have been widely used in studies focusing on earthworm community structure and biological invasions, as well as the effects of earthworms on vegetation, soil properties, carbon and nitrogen cycling, and ecosystem functions. We revisited this categorization system by analyzing the stable isotopes of carbon and nitrogen (13C and 15N) from 10 earthworm species commonly found in arable fields and deciduous forests in temperate North America. We showed that up to nine isotopic niches utilized by earthworms can be distinguished in the two-dimensional space delimited by δ13C and δ15N. Rather than forming distinct categories, isotopic niches of different ecological groups form a continuum, ranging from species feeding on leaf litter to those feeding on highly processed soil organic matter. Along this continuum, the three “traditional” groups are recognizable, and species of the same ecological group can exhibit considerable isotopic niche differentiation and resource partitioning. These results, together with field observations on native Lumbricidae in Europe, suggest that, despite their convenience, there are limitations to the commonly used ecological categories. We propose to incorporate stable isotopes as functional traits in studying earthworm ecology and the linkage between earthworm communities and ecosystem functions. Moreover, to fill existing knowledge gaps, the isotopic approach needs to be further expanded to native earthworm communities around the world, particularly outside Western Europe and North America, and to earthworm families and major taxonomic groups other than Lumbricidae, such as Glossoscolecidae, Acanthodrilidae, and Megascolecidae.

Onion downy mildew severity in no-tillage irrigation under nutrient budgeting and population densities

We analyzed the relationship between nutrient (N and K) parceling and population density on the severity of onion downy mildew under no-tillage fertigation cultivation in the conditions of Alto Vale do Itajaí (Barzil). For this purpose, field trials were conducted in the years 2017, 2018 and 2019, in Ituporanga (Barzil). The treatments corresponded to four population densities (300, 400, 500 and 600 mil plants ha-1) subjected to applications of nitrogen (150 kg N ha-1) and potassium (127.5 kg K2O ha-1) distributed throughout the vegetative cycle of the crop via fertigation on a weekly, biweekly and monthly basis, based on the absorption curve of these nutrients for the cultivar Empasc 352-Bola Precoce. In fertigated no-tillage systems, nutrient (N and K) tranches do not influence the severity of downy mildew. The severity of downy mildew increases linearly with increasing population density, especially from 500 mil plants per ha-1.

Fusion of Different Image Sources for Improved Monitoring of Agricultural Plots.

In the Valencian Community, the applications of precision agriculture in multiannual woody crops with high added value (fruit trees, olive trees, almond trees, vineyards, etc.) are of priority interest. In these plots, canopies do not fully cover the soil and the planting frames are incompatible with the Resolution of Sentinel 2. The present work proposes a procedure for the fusion of images with different temporal and spatial resolutions and with different degrees of spectral quality. It uses images from the Sentinel 2 mission (low resolution, high spectral quality, high temporal resolution), orthophotos (high resolution, low temporal resolution) and images obtained with drones (very high spatial resolution, low temporal resolution). The procedure is applied to generate time series of synthetic RGI images (red, green, infrared) with the same high resolution of orthophotos and drone images, in which gray levels are reassigned from the combination of their own RGI bands and the values of the B3, B4 and B8 bands of Sentinel 2. Two practical examples of application are also described. The first shows the NDVI images that can be generated after the process of merging two RGI Sentinel 2 images obtained on two specific dates. It is observed how, after the merging, different NDVI values can be assigned to the soil and vegetation, which allows them to be distinguished (contrary to the original Sentinel 2 images). The second example shows how graphs can be generated to describe the evolution throughout the vegetative cycle of the estimated values of three spectral indices (NDVI, GNDVI, GCI) on a point in the image corresponding to soil and on another assigned to vegetation. The robustness of the proposed algorithm has been validated by using image similarity metrics.

Effects of precipitation seasonality, irrigation, vegetation cycle and soil type on enhanced weathering – modeling of cropland case studies across four sites

Abstract. Enhanced weathering (EW) is a promising strategy for carbon sequestration, but several open questions remain regarding the actual rates of dissolution in conditions of natural hydroclimatic variability in comparison to laboratory experiments. In this context, models play a pivotal role, as they allow exploring and predicting EW dynamics under different environmental conditions. Here a comprehensive hydro-biogeochemical model has been applied to four cropland case studies (i.e., Sicily and the Padan plain in Italy and California and Iowa in the USA) characterized by different rainfall seasonality, vegetation (i.e., wheat for Sicily and California and corn for the Padan plain and Iowa), and soil type to explore their influence on dissolution rates. The results reveal that rainfall seasonality and irrigation when applied are crucial in determining EW and carbon sequestration dynamics, given their effect on hydrological fluxes, soil pH and weathering rate. The carbon sequestration rate was found to be strongly affected also by the background weathering flux, which is one of the main factors controlling soil pH before the olivine amendment. Regarding the US case studies, Iowa sequesters the greatest amount of CO2 if compared to California (4.20 and 2.21 kg ha−1 yr−1, respectively), and the same happens for Sicily with respect to the Padan plain (0.62 and 0.39 kg ha−1 yr−1, respectively). These low carbon sequestration values suggest that an in-depth analysis at the global scale is required to assess EW efficacy for carbon sequestration.

Evaluation of irrigation frequency on pineapple plants grown in greenhouse conditions

• Seasons affect the values of all the indicators (LCI, NDVI, SDD, RWC). • The sensitivity of the non-destructive indicator is higher than the destructive. • High and medium irrigation frequency show higher conversion of water into biomass. • High frequency shows higher crop water productivity at the end of vegetative cycle. The objectives of this work are to evaluate the water status and growth variables of pineapple plants under different frequencies of irrigation to optimize the water productivity irrigation in greenhouse conditions in the subtropics. The experiment was conducted during the vegetative cycle for nine months, comparing three frequencies of irrigation: irrigation every three days (High frequency-T1), every seven days (Medium frequency-T2), and every 15 days (Low frequency-T3). The water status was measured using destructive indicators: Relative Water Content (RWC) and non-destructive indicators: Normalized Difference Vegetation Index (NDVI), Stress Degree Day (SDD), and Leaf Chlorophyll Index (LCI). Water productivity indicators (Irrigated water productivity, crop water productivity) and growth variables (plant height, maximum diameter, plant biomass, assimilate partitioning) were also measured. The environmental conditions monitored were temperature, humidity, and incident radiation. The soil moisture depletion and daily depletion rate were also registered and calculated. Destructive indicators of water status did not detect differences between irrigation treatments in this study, while non-destructive indicators statistically differentiated T1 from T3. T2 was the most appropriate irrigation treatment during the cold season. These results suggest that in greenhouse conditions in subtropical environments, a combination of high frequencies in warm seasons and medium frequencies in cold seasons would adjust irrigation management according to the pineapple crop needs, optimizing irrigation water productivity.

Efficiency of foliar fertilization for the improvement of pomological parameters, mineral composition, carbohydrates status and polyphenols components in olive fruit cultivar Chemlali

Foliar fertilization in rain-fed olive orchards is used nowadays in order to improve the yields for the olive oil industry. The present work aimed to study the effect of foliar fertilization on the quality parameters of olive fruits. Three foliar fertilizers and biostimulants were applied on Chemlali olive cultivar, cultivated under rain-fed conditions in the center of Tunisia, at different stages from the vegetative cycle during two successive years. Six treatments formed the fertilization program: F1 (rich in nitrogen), F2 (rich in boron), F4 (a biostimulant rich in calcium), F3 (supplying an addition of F1 and F2), F5 (supplying an addition of F1, F2 and F4) and a control (without foliar fertilization). At the end of the experiment during the year 2015, fruits were harvested, freeze-dried and the characteristics of drupes and chemical composition of the fruits were evaluated: mineral composition, carbohydrates profile and individual polyphenols. Results showed that some treatments especially rich in Ca improved the fruit size. Foliar fertilization induced differences in the mineral content of fruits. Regarding carbohydrates, glucose was the main sugar present in the fruits and varied between 8.8 μg/mg dry weight (d.w) and 36.43 μg/mg (d.w.). Changes were clearly observed in the pool of the phenolic fraction. The combined treatment F5 showed the highest concentrations in oleuropein and hydroxytyrosol and were equal to 742.6 and 112.94 μg/g of fresh weight respectively. This work is of great interest because it showed the role of nutrients supply in improving the quality of olive fruits.

CAUSAS Y CONSECUENCIAS DE LA VARIACIÓN DEL CONTENIDO DE ADN EN ZEA

Cytogenetic evidence indicates that Zea, which comprises maize (Z. mays ssp. mays) and its wild relatives, is an allopolyploid genus. Our research group has carried out numerous cytogenetic studies on Zea species, mainly focused on native Argentinian and Bolivian maize landraces. We found a wide inter- and intraspecific genome size variation in the genus, with mean 2C-values ranging between 4.20 and 11.36 pg. For the maize landraces studied here, it varied between 4.20 and 6.75 pg. The objectives of this work are to analyze the causes of genome size variation and to discuss their adaptive value in Zea. This variation is mainly attributed to differences in the heterochromatin located in the knobs and to the amount of interspersed DNA from retrotransposons. Polymorphisms in presence or absence of B-chromosomes (Bs) and the population frequency of Bs are also a source of genome size variation, with doses ranging between one and eight in the landraces analyzed here. Correlation analysis revealed that the percentage of heterochromatin is positively correlated with genome size. In addition, populations cultivated at higher altitudes, which are known to be precocious, have smaller genome sizes than do those growing at lower altitudes. This information, together with the positive correlation observed between the length of the vegetative cycle and the percentage of heterochromatin, led us to propose that it has an adaptive role. On the other hand, the negative relationship found between Bs and heterochromatic knobs allowed us to propose the existence of an intragenomic conflict between these elements. We hypothesize that an optimal nucleotype may have resulted from such intranuclear conflict, where genome adjustments led to a suitable length of the vegetative cycle for maize landraces growing across altitudinal clines. Key words: B chromosomes, heterochromatin, intragenomic conflict, knobs, maize landraces

A combined in vitro–in silico approach for the discovery of novel endogenous enzymatic and ctDNA sequence of bioactive molecules from aerial and root parts of Centaurea sulphurea as antioxidant’s agents

The excess free radicals not neutralized by the antioxidant defenses damage the essential macromolecules of our cells, causing abnormalities in the expression of genes and membrane receptors, cell proliferation or death, immune disorders, mutagenesis, deposits of proteins or lipofuschin in tissues. The first objective of this study was to elucidate the composition of the essential oil of the aerial and root part of Centaurea sulphurea during beginning of the vegetative cycle (March), beginning of the flowering stage (April) and full bloom (May/June) using GC/FID and GC/MS. The second aim was to describe the antioxidant activity using three methods (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP), β-carotene bleaching assay) and bioinformatical study of ctDNA sequence and three endogenous enzymes inhibition. The essential oils obtained from the root during the full bloom period consisted mainly of caryophyllene oxide, aplotaxene and (Z)-phytol. While, the aerial parts were dominated by caryophyllene oxide, verridiflorol and humulene epoxide II. The results showed that essential oil presented an excellent antioxidant activity with IC50 values of 2.06 g/L and 1.29 g/L, for aerial and root parts, compared to butylated hydroxyltoluene (BHT) and Ethylenediaminetetraacetic acid (EDTA) controls and the nicotinamide adenine dinucleotide phosphate (NADPH) co-crystallized inhibitor. The results of the molecular docking revealed that (Z)-phytol (Ligand 39) has an affinity to interact with ctDNA sequence, and three targets Endogenous enzymes. The molecular dynamics study was conducted for the best inhibitors (Z)-phytol. A few key residues were identified at the binding site of receptors. The in-silico assessment of the ADME properties and BOILED-Egg plot reveals that compound (Z)-phytol (L39) is permeable to the blood brain barrier and have high lipophilicity and high coefficient of skin permeability in the intestines with good bioavailability. The ADMET analysis also showed that this oxygenated diterpene is safer to replace the synthetic drugs with side effects. Further testing is needed to assess its effectiveness in reducing oxidative stress for use in the pharmaceutical industry. Communicated by Ramaswamy H. Sarma

Quantifying and Reducing Uncertainty in Global Carbon Cycle Predictions: Lessons and Perspectives From 15 Years of Data Assimilation Studies With the ORCHIDEE Terrestrial Biosphere Model

AbstractPredicting terrestrial carbon, C, budgets and carbon‐climate feedbacks strongly relies on our ability to accurately model interactions between vegetation, C and water cycles, and the atmosphere. However, C fluxes simulated by global, process‐based terrestrial biosphere models (TBMs) remain subject to large uncertainties, partly due to unknown or poorly calibrated parameters. This is because TBMs have not routinely been confronted against C cycle related datasets within a statistical data assimilation (DA) system. In this review, we present 15 years' development of a C cycle DA system for optimizing C cycle parameters of the ORCHIDEE TBM. We analyze the impact of assimilating multiple different C cycle related datasets on regional to global‐scale gross and net CO2 fluxes. We find that assimilating atmospheric CO2 data is crucial for improving (increasing) ORCHIDEE predictions of the terrestrial land C sink. The improvement is predominantly due to the global‐scale constraint these data provide for optimizing initial soil C stocks, which are likely in error due to inaccurate assumptions about steady state spin‐up and incomplete knowledge of land use change histories. When comparing the data‐constrained ORCHIDEE land C sink estimates to the CAMS atmospheric inversion, we show that while the two approaches agree on the global C sink magnitude, they continue to differ in how the global C sink is partitioned between the northern hemisphere and tropics. We also discuss technical challenges faced in our C cycle DA studies, in particular the difficulty in characterizing the error covariance matrix due to unknown observation biases and/or model‐data inconsistencies. We offer our perspectives on how to tackle these challenges that we hope can serve as a roadmap for other TBM groups wishing to develop C cycle DA systems.

Effects of gamma irradiation on morphology and protein differential in M1V1 population of Vanilla planifolia Andrews

Purpose Lower doses (1–10 Krad) of gamma-rays (γ) are frequently used in obtaining useful mutants in diverse plant species, whereas no report on gamma (γ) irradiation being used to develop new varieties of vanilla from vanilla cuttings. This study assessed the potential of lower doses of gamma-rays for vanilla mutation breeding. Materials and methods We compared the morphological differences between vanilla plants irradiated at different lower doses of gamma radiation (10, 30, 40, and 50 Gy). We quantified protein and compared variation from the extracted protein of vanilla shoots regenerated between treatments. Results and conclusions After 44 weeks, the results showed that the growth of M1V1 (mutation 1 in vegetative cycle 1) plants at 0 Gy (control) is highest compared with other doses of gamma radiation in terms of plant height and the number of shoots. However, the highest measurement for root length is at 10 Gy. The slowest growth rate was obtained from 40 to 50 Gy. Based on the unique band of protein that appears on the SDS-PAGE gel, 10 Gy has three unique bands at loci 0.105 RF, two bands lie at loci between 0.164 RF and 0.234 RF. While 30 Gy is absent two unique bands at loci 0.234 RF compared to 0 Gy. Thus, the dose of gamma rays at 10 Gy gave the highest number of protein fragments, which detected polymorphisms between the control (0 Gy) and the plants treated. To our knowledge, this is the first report of the protein variation in M1V1 of irradiated vanilla plants.