Please login first

List of accepted submissions

 
 
Show results per page
Find papers
 
  • Open access
  • 19 Reads
How to Improve Already Improved Cowpea—Terminal Drought

Cowpea (Vigna unguiculata) is a heat and drought resistant legume which thrives in poor and marginal soils, also due to its symbiosis with nitrogen fixing bacteria. Its high protein content suggests this crop fits perfectly with the three dimensions of sustainable development; social, economic and environmental issues. Extensive use of commercial varieties causes genetic variability loss, compromising breeding efforts in a context of climate changes. To contribute to the evaluation of Portuguese cowpea germplasm, several landraces were compared with a commercial variety (CV) in terms of productivity and physiological responses to drought. Potted plants were grown in a semi-controlled environment and well irrigated during the vegetative growth. Water stress was induced during the reproductive phase in half of the plants. Physiological measurements were conducted during stress. At the end of the cycle pods and seeds were counted and weighted. Despite a clear effect of stress in photosynthesis, there were no differences between the CV and landraces. However, under drought higher relative chlorophyll content (SPAD), was kept for a longer time in CV. Both the CV and landraces showed a marked decrease in productivity (60 - 70%) under stress. The induced drought had no impact on grains weight. As expected, the CV produced bigger and heavier seeds, eventually more appealing to consumers. Results suggest that CV and the studied landraces present a similar behaviour, reflecting the species adaptation to Mediterranean climate. Molecular characterization of genetic diversity is on course using microsatellites.

  • Open access
  • 16 Reads
Getting into Structure-Activity Relationships of Ecdysteroids for Plant Protection Strategies against Insect Pests

The evolution of the organisms is the result of a complex and changing interaction (geno and pheno) with environment, on the basis of powerful and extraordinary efficient chemical machinery. During the development’s process three fundamental points define, evolutively, the success of it 1.the cell-internal control mechanisms, 2.external control of the cell, and 3. links between the environment and genes. The transformations of insects and typical invertebrates during the larval states (metamorphosis) in their life’s cycle is an example of the chemical signals system and mentioned above point 1. The ecdysone, the so-called “moulting and metamorphosis” hormone, following the classic steroids action mechanism, is produced by the prothoracic glands, after activation induced by neuropeptides. This compound ( and its derivatives) controls the morphogenesis and metamorphosis. In biological systems where target-chemical compound interactions define the cell internal control, the chemical reactivity as a quantitative term, depends of optimum geometric, electronic and chemical properties. Ecdysteroid activity of several naturally occurring and synthetic steroidal derivatives, starting from ecdysone and diosgenine, have been studied in the past 20 years and some interesting results have been achieved. This communication intends: 1- Quantitative determining which are the key points of the ecdysone molecule and analogues that trigger the action of the biological machinery, starting from the structure-activity relationship and the analysis of electronic properties, using a very simple protocol, and, 2-Propitiating a mathematical-statistic tool that allows to discriminate most active molecules from the less active ones, optimizing the synthesis of steroidal analogs with define ecdysteroid action, useful for applying in field conditions for controlling insect pests which affect the crop yields.

  • Open access
  • 10 Reads
Analysis of Plant-Insect Pollination Network—A Case Study on the Exotic Plants as Nectar Resource of Butterflies across Darjeeling District of West Bengal, India

In ecology, a bipartite network involving higher and lower tropic level components are a reflection of community interaction. Interesting studies on the pollinator-nectar plant relationship enlightens their role in the conservation and valuation of the environment. Additionally the contribution of exotic plants as nectar resource of pollinators could prove beneficial for studies on community structure and function. The present investigation on butterflies-exotic nectar plant community across Darjeeling district of West Bengal, India is of paramount importance in generating awareness for protection of such plant communities. Analysis of such bipartite network characterizing butterfly-plant community could help in elaborating the different aspects of species assemblage and interaction. Different indices (based on unweighed links and weighed links) were used for exploration of such network, A total of 28 exotic plant species served as nectaring resource for 44 butterfly species. Some ecologically significant descriptors of this network included network dimension (no. of species in higher trophic level: 44; no. of species in lower trophic level: 28), links per species (1.042),connectance (0.061) and network asymmetry (-0.222). Other indices based on weighed links included generality (3.608), vulnerability (3.166) and Shannon’s evenness of network interaction (0.4407). Thus the above predictions provide a probable clue to the involvement of exotic plant species to the maintenance of community structure. Significantly, exotic plants serve as key service providers to a community’s pollinator assemblages thereby attempting to fill an otherwise “empty coevolutionary niche”.

r

  • Open access
  • 55 Reads
Biostimulant Effect of Selected Eukaryotic Microalgae on Solanum lycopersicum L.
,

Microalgae have been found to positively influence plant growth. The objective of this study was to investigate the growth-promoting effects of two selected strains of eukaryotic green microalgae. The biostimulating effects of Chlorella (MACC-360) and the benchmark Chlamydomonas reinhardtii (cc124) species were investigated on Solanum lycopersicum L. model plant grown under controlled greenhouse conditions. We analyzed the physiological responses of S. lycopersicum (Vilma variety) to algal biomass addition. The plants were cultivated in pots containing a mixture of vermiculite and soil layered with clay at the bottom. The application of algae whole-cell suspensions using the soil drench method as well as foliar application of algae extract prepared by destruction and homogenization of microalgae cells in liquid nitrogen significantly affected the time and extent of flowering, the pigment content (chlorophylls and carotenoids), fruit number, fruit weight, fruit diameter. Algae treatment also increased total yields but not significantly. The biostimulant effect of microalgae on plants proved to be strain-specific. Chlorella strain promoted flowering which culminated in higher yields and earlier maturity than control. On the contrary, the Chlamydomonas strain increased fruit diameter but reduced fruit number per plant, relative to the control.

  • Open access
  • 33 Reads
Natural Enrichment of Solanum tuberosum L. with Calcium—Monitorization of Mineral Interactions in Plant Tissues

Calcium is an essential nutrient for plants, being required for several structural roles (such as in the membranes and in the cell wall). Although most of the Ca is obtained via the xylem (taken up by roots from the soil), in potatoes the accumulation of minerals is mainly obtained via the phloem. So, it’s crucial to understand the mechanisms of Ca and its interaction with other minerals in plant tissues of tubers. In this context, this study aimed to monitor the mineral interactions in tubers and leaves of Solanum tuberosum L. after two foliar sprays with solutions of calcium chloride (1,3,6 and 12 kg.ha-1) and calcium nitrate (0.5,1,2 and 4 kg.ha-1), in order to improve naturally the Ca content. It was found different increases of Ca in the two fertilizers, with a higher content in the leaves with calcium nitrate 2 kg.ha-1 and in the tubers with calcium chloride 12 kg.ha-1. Moreover, Ca accumulation showed a synergetic interaction with Mg in leaves, and with P, K and S in tubers. It was concluded that in the middle of Ca enrichment process in tubers plants there was a heterogeneous interaction between other minerals both in tubers and in leaves.

  • Open access
  • 12 Reads
Never-Ending Battle between Defense Metabolites of Indian Oilseed Mustard and the Necrotrophic Fungal Pathogen
, ,

Oilseed Brassicas stand first in the edible oil production of India1 however, are under constant threats from environmental challenges like the white mold disease caused by the necrotrophic phytopathogen Sclerotinia sclerotiorum2. Indeed, in case of oilseed mustard Brassica juncea, a dominant oilseed crop of the Indian subcontinent, white mold has become a major limiting factor both during pre and the post-harvest stages with >92% yield losses reported3. Brassica species produce a group of unique defense metabolites called glucosinolates, which along with their hydrolysis products are reported for toxicity against Sclerotinia both under in-vitro and in-vivo conditions4,5. Nevertheless, pathogens like Sclerotinia, are able to infect, colonize and cause significant yield losses on glucosinolate producing plants. In this context, we initially assessed the disease dynamics of S. sclerotiorum-B. juncea pathosystem at different time points and analyzed changes in the in-planta levels of different glucosinolates (C3, C4 and C5 fractions) during Sclerotinia infection. Our results suggest that, Sclerotinia infection activates the glucosinolate-myrosinase system by modulating changes in total and component glucosinolates of B. juncea plants throughout the time course of infection. We also assessed the toxicity of allyl-ITC (degradation product of sinigrin, an abundant glucosinolate in B. juncea cultivars) on the growth of Sclerotinia in-vitro and observed that this C3-aliphatic glucosinolate derived product, has proven to be one of the most toxic to Sclerotinia. In addition, we performed HPLC analysis to determine the glucosinolate content and types across 250 diverse germplasm accessions of B. juncea that span a range of variation in the glucosinolate metabolite trait, which shall be useful for identification of resistance to Sclerotinia in the mustard crop. Overall, this research work will be useful to understand the disease mechanism and enable selective manipulation of defense metabolites to prevent white mold disease losses in polyploid crop species.

REFERENCES:

  1. Jat, R.S., Singh, V.V., Sharma, P. and Rai, P.K., 2019. Oilseed Brassica in India: Demand, supply, policy perspective and future potential. Oilseeds & Fats Crops and Lipids, 26, pp.8.
  2. Del Rio, L.E., Bradley, C.A., Henson, R.A., Endres, G.J., Hanson, B.K., McKay, K., Halvorson, M., Porter, P.M., Le Gare, D.G. and Lamey, H.A., 2007. Impact of Sclerotinia stem rot on yield of canola. Plant Disease, 91(2), pp.191-194.
  3. Shukla, A.K., 2005. Estimation of yield losses to Indian mustard (Brassica juncea) due to Sclerotinia stem rot. Journal of Phytological Research, 18(2), pp.267-268.
  4. Sotelo, T., Lema, M., Soengas, P., Cartea, M.E. and Velasco, P., 2015. In vitro activity of glucosinolates and their degradation products against Brassica-pathogenic bacteria and fungi. Applied and Environmental Microbiology, 81(1), pp.432-440.
  5. Stotz, H.U., Sawada, Y., Shimada, Y., Hirai, M.Y., Sasaki, E., Krischke, M., Brown, P.D., Saito, K. and Kamiya, Y., 2011. Role of camalexin, indole glucosinolates, and side chain modification of glucosinolate‐derived isothiocyanates in defense of Arabidopsis against Sclerotinia sclerotiorum. The Plant Journal, 67(1), pp.81-93.
  • Open access
  • 22 Reads
Induction of Immune Response in Arabidopsis thaliana Treated with Phytopathogen Filtrates

Agricultural crops are increasingly affected by phytopathogenic diseases, rising production losses. Nevertheless, disease control using phytopathogenic microorganisms or their derivatives are still unknown. The aim of our study was to evaluate the effect of phytopathogen filtrates on Arabidopsis thaliana defense response and its development. The filtrates were obtained through liquid cultures, using Luria-Bertani broth to the bacteria Pseudomonas syringae and Pectobacterium carotovorum, and Potato Dextrose broth to the fungi Fusarium oxysporum f. sp. conglutinens, Sclerotinia sclerotiorum, and Ralstonia solani, and to the oomycete Pythium irregulare. The gene expression analysis of salicylic acid and jasmonic acid signaling pathways, through the genes ICS1 and PR1, and LOX1 and VSP2, respectively, showed that plants were able to activate a systemic defense response, giving significant expression levels in the leaves, despite the contact with the filtrates occurred at the roots. Also, we observed that with the exception of S. sclerotiorum, the other filtrates had a positive effect on plants growth, the aerial tissue being favored by R. solani and the root by P. irregulare. Moreover, there was no significant variation in the number of fruits. Additionally, we saw that pretreatment with fungal filtrates, especially of R. solani, favored the defense response of the plants against infection by the necrotrophic fungus Botrytis cinerea, which could be due to the elicitor molecules they have in common. These findings show that the use of phytopathogen filtrates in agriculture has the potential to reduce the application of pesticides through the use of the plant's own defense system.

  • Open access
  • 17 Reads
Detection of Celiac Active Polypeptides in Wheat, Oat and Buckwheat by Immunochemical Methods

Cereals and pseudocereals are one of the most important crops of agricultural production. Number of people suffering from food allergies and intolerances has been increasing in recent years and cereal proteins are the most common food allergens. Pseudocereals represent perspective alternative in nutrition with a positive effect on the human body, while do not cause celiac disease. The aim of the study was to analyze the proteome of the winter wheat (Triticum aestivum L.), common oat (Avena sativa) and common buckwheat (Fagopyrum esculentum Moench.) genotypes by immunochemical methods and to detect the presence of potentially allergenic proteins. The results of ELISA confirmed a high gluten content in wheat (43 278.51 mg.kg-1), which does not fulfil the set limit for gluten-free food. Two analyzed oat varieties Vendelin (44.71 mg.kg-1) and Valentin (57.37 mg.kg-1) can be characterized as crops with a low gluten content. The oat variety Zvolen (10.57 mg.kg-1) and all three analyzed buckwheat varieties (average 2.03 mg.kg-1) fulfil the criteria for labeling as gluten-free food. The results confirm the oat varietal dependence on the content of allergenic proteins. Western blot analysis revealed the strongest reaction of polyclonal antibody with wheat proteins with a molecular weight in the range of 25 kDa to 50 kDa. In oat, the strongest signal was detected in proteins with a molecular weight of 20 kDa and also 40 kDa-55 kDa. No signal was detected in buckwheat, which was confirmed by ELISA results. Based on the above, buckwheat can be recommended as a safe crop for the preparation of gluten-free foods.

  • Open access
  • 53 Reads

α-Amylase Inhibitory Secondary Metabolites from Artemisia pallens Wall ex DC – Biochemical and Docking Studies

Diabetes Mellitus Type-2 (DM-2) has become a challenging disease worldwide as many young adults are also getting affected by it due sedentary lifestyle and wrong diets. Multiple studies have shown that control over α-amylase enzyme in gut could be a better approach to treat DM-2. The secondary metabolites produced by the plants have various biological properties and many are used as drugs. In the current study, we isolated secondary metabolites from acetone leaf extracts of Artemisia pallens Wall ex DC (Family: Asteraceae) and tested them for their porcine pancreatic α-amylase (PPA) inhibitory activity in vitro and in silico. This extract exhibited good PPA inhibition, with IC50 value of 388.05 µg/ml. The IC50 value of Acarbose (a known pancreatic α-amylase inhibitor drug / positive control) was 9.71 µg/ml. Various secondary metabolites detected from acetone leaf extract by LC-MS analysis, were used for the molecular docking studies using AutoDock 4.2.6. The co-crystallised structure of PPA and Acarbose was retrieved from Protein Data Bank (PDB ID: 1OSE). The binding energies of few metabolites were (kcal/mol): Isoquercetin (-11.57), Cryptochlorogenic Acid (-11.17), Cirsilineol (-10.24), Kaempferide (-9.99), Fustin (-9.86), 6- Demetroxycapillarisin (-9.82), Piperine (-9.45), Ergometrine (-9.43), Apigenin (-9.38) & Artemisinin (-9.27). Acarbose had a binding energy of -17.58 kcal/mol. All the metabolites looked highly promising as α-amylase inhibitors and most of them interacted with PPA via hydrogen bonding with crucial amino acid residues: ASP197, ASP300 & GLU233. Thus the acetone extract of A. pallens leaves can potentially inhibit PPA (strong amino acid sequence similarity with human pancreatic α-amylase) and hence extrapolation of these inhibitory results could be valid for human pancreatic α-amylase as well.

  • Open access
  • 8 Reads
Within-Canopy Variation in the Ascorbic Acid Content of Tuckeroo (Cupaniopsis anacardioides) Fruits

Although fruit canopy position is known to affect phytochemical composition in a number of commercial crops, there is limited information on its impact on the nutritional quality of native Australian fruit. This study is the first to quantify ascorbic acid in tuckeroo (Cupaniopsis anacardioides) fruit and investigate the impact of canopy position in this species. High levels of ascorbic acid were found in the skin (mean of 423 ± 61 mg/100 g on a dry weight basis) and arils (60.0 ± 18.8 mg/100g), but not in the seeds (mean of 15.6 ± 4.3 mg/100g). The tree, side and height all significantly affected fruit mass, with larger fruit located on the northern bottom side of the canopy. Skin ascorbic acid content also varied significantly with the tree (responsible for 50.8% of the total variance observed in vitamin C content), canopy height (accounting for 0.9% of the total variance), with a marginal impact of the side (compass direction). Fruit from the top of the southern side of the tree typically had the highest ascorbic acid content. This inter-tree and within-canopy variation in the nutritional content of C. anacardioides fruit may have implications for sampling protocols and potential harvesters of this fruit.

Top