Please login first

List of accepted submissions

Show results per page
Find papers
  • Open access
  • 66 Reads
Characterization of Mineral Interactions in Two Varieties of Lycopersicum esculentum L. Produced Organically and Enriched Naturally with Fe and Zn

Plants need certain micronutrients for normal and healthy growth, namely iron and zinc. However, Fe and Zn have low kinetic mobility in soils and in plants. In fact, in tomatoes plants, Fe showed low mobility in phloem and due to soil interactions, that can reduce Fe uptake, foliar spraying is one of the most effective strategies to deal with this soil-plant interaction. Nevertheless, foliar sprayings with Zn presented an increase in its content in the edible part of plants. In this context, nutrient interactions were monitored in two commercial varieties (“chucha” and “maçã”) of Lycopersicum esculentum L. after two foliar sprays with a mix of two products of Fe and Zn (treatment 1 and 2), following an organic production mode. In leaves of the two varieties, Zn showed a higher content in treatment 1. Yet, considering Fe, “maçã” variety also showed a higher content in treatment 1, unlike “chucha” variety, which presented a higher content in treatment 2. Regarding tomatoes of “maçã” variety, Zn showed an antagonistic trend with Ca, K and S. In conclusion, after two foliar sprays of Fe and Zn, in tomatoes, there was possible to identify a nutrient interaction between other minerals mainly in “maçã” variety, although both varieties were produced under the same soil conditions.

  • Open access
  • 81 Reads
Interactions between Zn Enrichment of Grapes cv. Syrah Fertilized with ZnO and Photoassimilates Mobilization

Micronutrients have an important role in crops, namely Zn, being responsible for several physiological pathways, improving crops quality and growth. Zinc role is related to enzymes activity, carbohydrate metabolism, photosynthesis, protein metabolism and maintenance of the integrity of biological membranes. Considering his importance and the deficiency observed worldwide, an itinerary of foliar spraying with zinc oxide (ZnO) in vines of cv. Syrah during the production cycle, was outlined at Biscaia field in Palmela, Portugal (38º 35’23.629’’N; 8º 51’ 46.208’’ W). The treatment applied has concentrations of 10% and 30% (150 and 450 g ha-1). At harvest, Zn concentration in grapes, reached a maximum increase of 55 % with the highest treatment concentration, face to control. Also, leaf gas exchange after foliar spraying, didn’t present toxic signs in both concentrations, even being observed a positive impact in Pn and iWUE, thus contributing to biomass levels. Moreover, remote detection through Unmanned Aerial Vehicles (UAV’s), allowed to obtain the morphology of the field, being observed a superficial drainage capacity of 65 % with water lines in the direction of NW-SE and SE sense, along the lines of the vines, also contributing to quality of the crops. This strategy of Zn enrichment, demonstrated to have potential benefits for crops, being additionally advantageous for consumption since this micronutrient has several important functions.

  • Open access
  • 58 Reads
Transcriptome Characterization of Different Tissues of Stone Pine (Pinus pinea L.): de novo Assembly

Stone pine (Pinus Pinea L.) is an emblematic tree currently distributed around the whole Mediterranean basin. The species is well known for the economics of its timber and its seeds, the pine nuts, which are commercialized in food industry. The Iberian Peninsula accounts for the 75% of the world stone pine distribution, being Portugal the second country with the largest area of stone pine, after Spain.

Despite its relevance, the genomic information available for the species is scarce due to the limited studies and data available. Until now no reference genome available. However, advances in sequencing technologies, such as RNAseq, have allowed the characterization of the transcriptome even for species with no reference genome available. The main purpose of this study was to characterize the stone pine transcriptome of seven tissues (needles, xylem, stem bark, terminal bud, first and second year pine cone and pine nuts) by performing a de novo transcriptome assembly. A transcriptome comprising 165,179 contigs with an accumulative size of 81,31 Mbps was generated. A total of 55,328 genes were predicted, which from 50,161 (90.66%) genes had at least one homologous hit against the SWISS-PROT and/or non-redundant NCBI databases. Additionally, InterPro signatures were assigned identifying protein domains and associating GO terms and KEGG pathways. Together, these results represent the first transcriptome characterization of multiple tissues of stone pine. The assembled and annotated sequences will be deposited in a public repository.

Further analysis are ongoing to identify differences in gene expression between tissues.

Acknowledgements: This work was co-financed by Program Alentejo 2020, through the European Fund for Regional Development under the scope SelectPinea- Development of genetic markers for relevant traits in stone pine (ALT20-03-0145-FEDER-000041). Authors also acknowledge FCT for Contrato – Programa to L. Marum (CEECINST/00131/2018) and FCT for UIDB/05183/2020

  • Open access
  • 16 Reads
Overexpression of Plant Specific Insert from Cardosin B (PSI B) in Arabidopsis Correlates with Cell Responses to Stresses

Under abiotic stress, several changes occur in plant cells both regarding their physiology and cellular and molecular mechanisms. These are reflected in cell division, growth and differentiation of new structures. Plants have developed sophisticated mechanisms to overcome stress conditions, specifically modifications in the production and trafficking of proteins, and remodelling of endomembranes. Cardosins A and B are aspartic proteinases present in the thistle flower that have emerged as model systems to study intracellular trafficking due to the presence of a 100 amino acid domain named Plant Specific Insert (PSI), that is able to mediate transport to the vacuole. It is known that stress situations can alter the targeting of proteins to the vacuole shifting their transport towards more unconventional, Golgi-independent, routes. Given that PSIs may mediate such routes, our goal was to evaluate if transgenic Arabidopsis plants overexpressing PSI B respond differently when subjected to different abiotic stresses (osmotic, oxidative, salt, and metal). We analyzed biometric parameters, the expression of PSIB by qRT-PCR and the localization of PSI B-mCherry, in seedlings grown under stress. The results obtained point to a differential expression of PSI B-mCherry depending on the type of stress. Confocal microscopy observations showed a higher accumulation of PSI B m-Cherry in vacuoles from plants under hydric stress and a decrease of cellular and cytoplasmatic movement in all stress situations. In summary, PSI B overexpression seems to be correlated with the stress response of plant cells, suggesting that it might mediate adaptation/defense mechanisms against adverse conditions.

  • Open access
  • 46 Reads
Study of Osmotic Behavior of Astasia longa and Dunaliella salina Cells as an Important Stage in Developing Their Cryopreservation Protocol

The study of osmotic parameters of cells is an important step in successful cryopreservation. The aim of this work was to study the osmotic reactions of cells of different taxonomic groups (euglenoid Astasia longa, microalga Dunaliella salina) in response to complementing with of promising cryoprotectants (Me2SO4, glycerol, ethanol) under normothermic conditions.

Addition of 1-10% Me2SO4 solutions to A. longa cells led to a change in cell shape, loss of plait and motility, reduction of the relative area of cells by 10-27%, which after washing is restored only partially. The 1% ethanol and 1-5% glycerol solutions did not affect the condition of A. longa cells. The 5-10% ethanol solutions decreased the cell area by 78.93-82.88%, the cells lost harnesses and mobility. A. longa was insensitive to 1-5% glycerol solutions; at 10% solution single cells lose flagella, cell area decreased by 70.8%. Rehydration occurred instantly.

Complementing with of 1-30% glycerol to the suspension of D. salina cells did not affect their condition. Exposure to 1-30% Me2SO4 did not significantly affect the relative area and did not lead to irreversible plasmolysis. Addition of 1-10% ethanol solutions did not lead to cell death, and the relative area decreased by 3-30%. Washing of all samples helped to restore the relative area and shape.

Thus, D. salina cells are osmotically tolerant to different concentrations of promising solutions of cryoprotectants. Whereas A. longa is more vulnerable to osmotic stress and can withstand only short-term exposure with 1-5% solutions of ethanol and glycerol.

  • Open access
  • 23 Reads
Effect of Origanum vulgare subsp hirtum essential oil on metabolite profile of Solanum tuberosum

Essential oils are intensively studied in recent years as promising bio-herbicides. A strong inhibitory activity on seed germination and phytotoxic effect on seedling growth have been reported for Origanum vulgare subsp hitum (Link) Ietswaart essential oil. It has also been found that the phytotoxic effect is weaker in the treatment of plants at a more advanced stage in their development. Thus, when treating potato plants with a height of 30-40 cm with aqueous solutions of essential oil, the effect comes down to the appearance of single spots on the leaves, which does not disturb the growth of the plants. In the present study, the metabolic profiles of healthy leaves of control potato plants and leaves with spots formed as a result of processing with aqueous solutions of Origanum vulgare subsp hirtum essential oil, were comparatively analyzed. The metabolite analysis was made by GC/MS. Potato plants were treated with concentrations of essential oil - 5 and 10 µl/mL. The leaves were collected 7 days after treatment. Metabolites representatives of basic groups of substances - amino acids, organic and phenolic acids, mono- and disaccharides were identified. In the damaged leaves, a higher content of monosaccharides - fructose and glucose, pyroglutamic acid and amino acids – proline, serine, aspartic acid, was found compared to control leaves. A less differences were found in terms of the accumulation of chlorogenic, ferulic, and quinic acids, sucrose. The results presented complement the knowledge of a plant reaction to abiotic stress.

  • Open access
  • 163 Reads
Environmental Correlates of Vegetation Distribution in Rajkandi Hill Reserve of Bangladesh

The present study aims to determine the relationship between plant species and environmental variables. The location of the study was the natural forests of Rajkandi Hill Reserve, Bangladesh. There were sampled in total 50 circular plots 13m radius for the collection of functional and vegetation data. Cluster analysis using PC-ORD, ver.6 has been used to determine the communities, and DCA and CCA analysis using CANOCO- 4.5 have been used to determine the species distribution pattern and relationship with environmental variables. In total 90 plant species belonging to 50 families were identified. Family Moreceae and Verbenaceae comprise higher species numbers in comparison to other families. By the Cluster analysis, three different communities were identified. Lippia alba-Clerodendrum viscosum community consists of the highest number sample plots (21), and 67 plant species belonging to 34 families which mostly occur in the valley land with moderately acidic soil. Amomum corynostachyum-Mallotus roxburghianus community represents the highest number of unique species in comparison to other communities has the strong preference for hill ridge site. DCA analysis clarified 18.4% of the variance in species data and CCA ordination clarified 67.2% of the variance of species-environmental relation and identified that Disturbance, soil P, and K are the significant variables that govern species compositional variation in the Rajkandi Hill Reserve. Rajkandi Hill Reserve forest has high structural complexity and shows a distribution pattern of plant communities. Each community indicates the habitat types and species-environmental variables relation which would be helpful for conservation purposes.

  • Open access
  • 65 Reads
Phenotypic Characterization of Lentil Genotypes for P Uptake and Utilization Efficiency at Seedling Stage

Phosphorus (P) is an essential, non-renewable nutrient for crop productivity worldwide. P is immobilized in the soil, which limits its uptake and utilization by the plants. Breeding for P uptake and utilization efficiency is the most sustainable strategy to employ available resources in the best possible way. The present study was carried out to identify P uptake and utilization efficient lines under low p condition at seedling stage in lentil. A set of diverse lentil genotypes (85) belonging to six different Lens species was screened under normal and low P condition in hydroponics under controlled environment. Significant reduction in root dry weight (RDW), shoot dry weight (SDW) and total dry weight (TDW) was evident under low P condition. TDW, SDW and RDW were significantly correlated to P uptake efficiency (PupE) and P utilization efficiency (PutiE) in lentil. PupE ranged from 19.50 to 266.49 mg plant-1 under low P and PutiE ranged from 30.53% to 97.50%. Based on TDW under low P, EC718309, EC718348, and EC718332 were found promising for PupE while PL06 and EC718332 exhibited better PutiE. EC718332 was observed as efficient and responsive genotype for both P uptake and utilization. These identified genotypes can be used as trait donor for breeding lentil varieties for low P environment.

  • Open access
  • 39 Reads
Exogenous Nitric Oxide Promotes Growth and Enhances Tolerance against Drought Stress in Banana

Drought stress is a major factor limiting crop yield. Nitric oxide (NO) is an important signal molecule that plays diverse roles in plant growth and defensive responses. However, little is known about the role of NO produced by plants under drought stress. In this study, we investigated the effects of sodium nitroprusside (SNP), an NO donor, on polyethylene glycol (PEG)-induced drought stress in bananas. PEG treatment alone or in combination with SNP and 2-(4-carboxyphenyl)-4,4,4,5,5,-tetra-methyllimidazoline-1-oxyl-3-oxide (cPTIO; an NO scavenger) was evaluated. PEG treatment significantly reduced plant growth. However, the application of SNP significantly alleviated the inhibiting effect of the drought stress in a dose-dependent manner. In contrast, the cPTIO at a concentration equimolar to the SNP reversed the effect, suggesting that the promotive effects may be due to NO itself. We then applied a gel-based proteomic approach to investigate the drought responses of bananas to define the role of NO. Ten proteins from 26 protein spots were identified using LC-MS/MS analysis. The majority of these proteins were stress-response and carbohydrate and energy metabolism-related proteins. These findings suggest that exogenously applied NO can appreciably improve drought tolerance in bananas, affirming its role in this stress-survival mechanism.

  • Open access
  • 58 Reads
Nutrient Passage in Different Grafted Lemon Trees

Spain is one of the most important productor of lemon fruits in the world. Also, about 80 % of the Spanish production of lemons is located in the arid southeast, where the fertirrigation is important to ensure the highest productivity. The aim of the present study was to determine the content of nutrients present in two different grafted lemon tree (Citrus x limon) of the Verna variety, located in a drip irrigation farm in Librilla (Region of Murcia, Spain). The first one grafted in a Sweet orange (Citrus x sinensis) rootstock, and the second one in a Bitter orange (Citrus x aurantium). Both in a 40 year old trees grown in a conventional agricultural practices. The Bitter orange rootstock (Citrus x aurantium) favoured the appearance of the "Miriñaque" or protuberance of the trunk at the union of the graft. While in Sweet orange rootstock (Citrus x sinensis) did not appeared. For the analysis, fresh samples of old leaf, young leaf and root were collected from 5 different trees for each rootstock. Once processed after having been weighed, dried and ground, they were analysed by inductively coupled plasma (ICP) analysis (Optima 3000, PerkinElmer). The result showed that the growth was higher in the aereal biomass was higher in Verna grafted on Sweet orange rootstock. The root samples of the lemon tree with Bitter orange rootstock contained a higher amount of Fe, Mn and Zn than the samples of the lemon tree Sweet orange rootstock. The rest of the nutrients did not show significant differences. The new and old leaves of Verna on Sweet orange rootstock showed higher amount of Fe, Mn and Zn than the new and old leaves of Verna on Bitter orange rootstock. Also, the rest of the nutrients did not showed significant differences. The study revealed that this protuberance in the trunk prevents the passage of these elements from the root to the aerial part of the trunk. This is probably related to the cell to cell passage.