scholarly journals Olive Varieties under UV-B Stress Show Distinct Responses in Terms of Antioxidant Machinery and Isoform/Activity of RubisCO

2021 ◽  
Vol 22 (20) ◽  
pp. 11214
Author(s):  
Chiara Piccini ◽  
Giampiero Cai ◽  
Maria Celeste Dias ◽  
Márcia Araújo ◽  
Sara Parri ◽  
...  

In recent decades, atmospheric pollution led to a progressive reduction of the ozone layer with a consequent increase in UV-B radiation. Despite the high adaptation of olive trees to the Mediterranean environment, the progressive increase of UV-B radiation is a risk factor for olive tree cultivation. It is therefore necessary to understand how high levels of UV-B radiation affect olive plants and to identify olive varieties which are better adapted. In this study we analyzed two Italian olive varieties subjected to chronic UV-B stress. We focused on the effects of UV-B radiation on RubisCO, in terms of quantity, enzymatic activity and isoform composition. In addition, we also analyzed changes in the activity of antioxidant enzymes (SOD, CAT, GPox) to get a comprehensive picture of the antioxidant system. We also evaluated the effects of UV-B on the enzyme sucrose synthase. The overall damage at biochemical level was also assessed by analyzing changes in Hsp70, a protein triggered under stress conditions. The results of this work indicate that the varieties (Giarraffa and Olivastra Seggianese) differ significantly in the use of specific antioxidant defense systems, as well as in the activity and isoform composition of RubisCO. Combined with a different use of sucrose synthase, the overall picture shows that Giarraffa optimized the use of GPox and opted for a targeted choice of RubisCO isoforms, in addition to managing the content of sucrose synthase, thereby saving energy during critical stress points.

2021 ◽  
Vol 60 (1) ◽  
pp. 165-174
Author(s):  
Toufic ELBEAINO ◽  
Magdalena CARA ◽  
Shpend SHAHINI ◽  
Pasko PANDELI

Forty samples representing 14 native Albanian and two foreign olive varieties were collected from an olive varietal collection plot in the Valias region (Tirana, Albania). The samples were assayed by RT-PCR for presence of olive-infecting viruses, including arabis mosaic virus (ArMV), cherry leaf roll virus (CLRV), cucumber mosaic virus (CMV), olive latent ringspot virus (OLRSV), olive latent virus 1 (OLV-1), olive leaf yellowing-associated virus (OLYaV), strawberry latent ringspot virus (SLRSV) and by PCR for the bacterium Xylella fastidiosa (Xf). Ninety-eight percent of the samples were infected with at least one virus. OLYaV was the most prevalent (85% of samples), followed by OLV-1 (50%), OLRSV (48%), CMV (28%), SLRSV (3%) and CLRV (5%), whereas ArMV and Xf were absent. Fifty-five percent of the samples were infected with one virus, 13% with two viruses, 20% with three, and 5% with four. Analyses of the nucleotide sequences of the Albanian virus isolates generally showed low genetic variability, and that most were phylogenetically related to Mediterranean isolates, in particular to those from Greece and Italy. Five olive trees, representing three native cultivars (‘Managiel’, ‘Kalinjot’ and ‘Kushan-Preze’) and one foreign (‘Leccino’), were found to be plants of the Conformitas Agraria Communitatis (“CAC”) category i.e. free of ArMV, CLRV, SLRSV and OLYaV. Only one tree of the native cultivar ‘Ulliri i kuq’ was free of all tested viruses, so this is plant material of the “Virus-tested” category. Olives derived from both categories could be used for propagation of standard quality plant materiel in a future certification programme for olive in Albania. This is the first report of CLRV, OLRSV, CMV and OLV-1 in Albania. The study also reveals the precarious health status of native olive varieties in the Valias varietal collection plot. However, the discovery of six plants representing two certifiable categories is a first step in a future olive tree certification program in the country.


2013 ◽  
Vol 3 (2) ◽  
pp. 111-115 ◽  
Author(s):  
Wendy Babcox

Every Olive Tree in the Garden of Gethsemane is a suite of photographic images of each of the twenty-three olive trees in the garden. Situated at the foot of the Mount of Olives in Jerusalem, the Garden of Gethsemane is known to many as the site where Jesus and his disciples prayed the night before his crucifixion. The oldest trees in the garden date to 1092 and are recognized as some of the oldest olive trees in existence. The older trees are a living and symbolic connection to the distant past, while younger trees serve as a link to the future. The gnarled trunks seem written with the many conflicts that have been waged in an effort to control this most-contested city; a city constantly on the threshold of radical transformation.


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 574
Author(s):  
Evanthia Xylogianni ◽  
Paolo Margaria ◽  
Dennis Knierim ◽  
Kyriaki Sareli ◽  
Stephan Winter ◽  
...  

Field surveys were conducted in Greek olive orchards from 2017 to 2020 to collect information on the sanitary status of the trees. Using a high-throughput sequencing approach, viral sequences were identified in total RNA extracts from several trees and assembled to reconstruct the complete genomes of two isolates of a new viral species of the genus Tepovirus (Betaflexiviridae), for which the name olive virus T (OlVT) is proposed. A reverse transcription–polymerase chain reaction assay was developed which detected OlVT in samples collected in olive growing regions in Central and Northern Greece, showing a virus prevalence of 4.4% in the olive trees screened. Sequences of amplified fragments from the movement–coat protein region of OlVT isolates varied from 75.64% to 99.35%. Three olive varieties (Koroneiki, Arbequina and Frantoio) were infected with OlVT via grafting to confirm a graft-transmissible agent, but virus infections remained latent. In addition, cucumber mosaic virus, olive leaf yellowing-associated virus and cherry leaf roll virus were identified.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1299
Author(s):  
Pablo Doménech ◽  
Aleta Duque ◽  
Isabel Higueras ◽  
José Luis Fernández ◽  
Paloma Manzanares

Olive trees constitute one of the largest agroindustries in the Mediterranean area, and their cultivation generates a diverse pool of biomass by-products such as olive tree pruning (OTP), olive leaves (OL), olive stone (OS), and extracted olive pomace (EOP). These lignocellulosic materials have varying compositions and potential utilization strategies within a biorefinery context. The aim of this work was to carry out an integral analysis of the aqueous extractives fraction of these biomasses. Several analytical methods were applied in order to fully characterize this fraction to varying extents: a mass closure of >80% was reached for EOP, >76% for OTP, >65% for OS, and >52% for OL. Among the compounds detected, xylooligosaccharides, mannitol, 3,4-dihydroxyphenylglycol, and hydroxytyrosol were noted as potential enhancers of the valorization of said by-products. The extraction of these compounds is expected to be more favorable for OTP, OL, and EOP, given their high extractives content, and is compatible with other utilization strategies such as the bioconversion of the lignocellulosic fraction into biofuels and bioproducts.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1304
Author(s):  
Francisco Espínola ◽  
Alfonso M. Vidal ◽  
Juan M. Espínola ◽  
Manuel Moya

Wild olive trees have important potential, but, to date, the oil from wild olives has not been studied significantly, especially from an analytical point of view. In Spain, the wild olive tree is called “Acebuche” and its fruit “Acebuchina”. The objective of this work is to optimize the olive oil production process from the Acebuchina cultivar and characterize the oil, which could be marketed as healthy and functional food. A Box–Behnken experimental design with five central points was used, along with the Response Surface Methodology to obtain a mathematical experimental model. The oils from the Acebuchina cultivar meet the requirements for human consumption and have a good balance of fatty acids. In addition, the oils are rich in antioxidants and volatile compounds. The highest extraction yield, 12.0 g oil/100 g paste, was obtained at 90.0 min and the highest yield of phenolic compounds, 870.0 mg/kg, was achieved at 40.0 °C, and 90.0 min; but the maximum content of volatile compounds, 26.9 mg/kg, was obtained at 20 °C and 30.0 min. The oil yield is lower than that of commercial cultivars, but the contents of volatile and phenolic compounds is higher.


2021 ◽  
Vol 83 (4) ◽  
Author(s):  
Sebastian Aniţa ◽  
Vincenzo Capasso ◽  
Simone Scacchi

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.


Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1216-1216 ◽  
Author(s):  
M. E. Sánchez-Hernández ◽  
A. Ruiz-Dávila ◽  
A. Trapero-Casas

Several species of the genus Phytophthora are associated with root rot and trunk cankers in olive trees (Olea europaea L.). Among them, Phytophthora megasperma has been cited as being associated with olive root rots in Greece (1). Unidentified species of Pythium and Phytophthora have also been associated with olive tree root rots in the United States. However, the status of P. megasperma and Pythium spp. as olive tree root pathogens has remained unclear. Following a 5-year period of severe drought in southern Spain, autumn-winter rainfall rates in 1996 to 1997 steadily increased in both quantity and frequency. Under these unusually wet conditions, olive trees remained waterlogged for several months. During this period, we observed foliar wilting, dieback, and death of young trees, and later found extensive root necrosis. In 46 of 49 affected plantations surveyed, P. megasperma was consistently isolated from the rotted rootlets, particularly in young (<1- to 10-year-old trees) plantations. This fungus was not detected on plant material affected by damping-off from several Spanish olive tree nurseries. The opposite situation occurred with P. irregulare. This species was not associated with rotted rootlets in the field. In contrast, it was consistently isolated from necrotic rootlets from young olive plants affected by damping-off. These plants were grown in a sand-lime-peat soil mixture under greenhouse conditions and showed foliar wilting and extensive necrosis of the root systems. Pathogenicity tests were conducted with several isolates of P. megasperma and P. irregulare on 6-month-old rooted cuttings of olive, under both weekly watering and waterlogged conditions. Under waterlogged conditions, both fungal species produced extensive root necrosis 2 weeks after inoculation that resulted in wilting of the aerial parts and rapid plant death. Waterlogged control plants remained without foliar symptoms but a low degree of root necrosis was recorded. In addition, under weekly watering conditions, plants inoculated with either species showed some degree of root rot but foliar symptoms were not evident. No differences in pathogenicity were observed within the Phytophthora or Pythium isolates. Reference: (1) H. Kouyeas and A. Chitzanidis. Ann. Inst. Phytopathol. Benaki 8:175, 1968.


2019 ◽  
Vol 9 (2) ◽  
pp. 64-71
Author(s):  
Benyoub Kheira ◽  
Kacem Mourad ◽  
Kaid-Harche Meriem

The present study on olive tuberculosis commenced by isolating bacteria of the genus Pseudomonas from the soils and necrosis of collected olive trees. A total of 180 samples were used in this study: (100) rhizospheric soil samples: (60) samples at the region of Ain Témouchent and (40) at the region of Sig in western of Algeria. In total, (80) galls were collected (40) at branch level and (40) galls at olive tree leaf (level). The isolates were identified by microbiological (macroscopic and microscopic examination), physiological (growth in the presence of Salt (NaCl), growth at different pH values and growth at different temperatures) and biochemical methods (the LOPAT and Galeries Api 20 NE test to identify species of the Pseudomonas group and conventional biochemical tests to identify the subspecies P. syringae pv. Savastanoi).This allowed to identify 110 isolates of Pseudomonas (60 isolates of P. aeruginosa, 35 isolates of P. fluorescens and 15 isolates of P. syringae pv Savastanoi the causal agent of olive node disease) which are now part of the collection of Pseudomonas bacteria of the laboratory of the Biotechnology Department (USTO-MB). The selection of technological performance isolates useful for our agriculture could solve phytopathological problems and finally constitute a collection of the bacteria preserved.


Plant Disease ◽  
2020 ◽  
Author(s):  
Jacson Ferreira ◽  
Thays Benites Pereira ◽  
Cláudia Alves Almeida ◽  
Ivan Paulo Bedendo

Olive trees exhibiting slow development, yellowing, and high intensity of shoot proliferation with small leaves were observed in commercial plantings, in the municipality of Extrema, Minas Gerais (MG) state in 2015. The incidence of symptomatic plants was about 70% and diseased trees presented yield reduction. Here we report the association of symptomatic olive trees with a phytoplasma and describe its molecular identification. Symptomatic plants (38 trees) were sampled in three growing areas located in the same municipality. The samples consisted of bunch of leaves and young shoots. The total DNA was extracted using DNeasy® Plant Mini Kit (Qiagen, Hilden, Germany). Phytoplasma detection was conducted by nested PCR with primers P1/16S-SR (Lee et al. 2004) followed by R16F2n/R16R2 (Gundersen and Lee 1996). PCR assays generated amplicons (~1.2 kb) from 28 trees out of 38 symptomatic plants, confirming the association of phytoplasma with diseased plants. The disease was named olive witches’ broom. The genomic fragments amplified by nested PCR were cloned into Escherichia coli DH5α and sequenced. The sequence representative of the olive phytoplasma was designated OWB-Br01 (Olive Wiches' Broom-Brazil 01) and deposited in GenBank under accession number MH141985. This sequence shared 99% sequence identity with phytoplasmas affiliated with 16SrVII group. According to the iPhyClassifier online tool (Zhao et al. 2009) the olive witches’-broom phytoplasma was classified as a variant of subgroup 16SrVII-B with a pattern similarity coefficient of 0.99. The phylogenetic tree showed that OWB-Br01 phytoplasma emerges from the same branch of the reference phytoplasma of the 16SrVII-B subgroup (Erigeron witches᾽-broom phytoplasma - GenBank AY034608), indicating that the olive tree phytoplasma is a member of the 16SrVII-B subgroup. The pathogenicity test was performed with 28 healthy plants (cultivar Arbequina) grown in pots, which were grafted by simple english forklift with scions obtained from olive plants (Arbequina) six years old, naturally infected by the phytoplasma. The initial symptoms were observed four months after grafting and at eight months 22 grafted plants exhibited slow growth, yellowing, and small leaves as those naturally observed in the fields. Molecular characterization allowed identify the phytoplasma as a member of the 16SrVII-B subgroup. In Brazil, representatives of the 16SrVII group were previously reported in association with diverse botanical species. Thus, a strain of 16SrVII-C subgroup was identified in sunn hemp (Flôres et al. 2013); the reference phytoplasma of 16SrVII-D subgroup was found in erigeron plants (Flôres et al. 2015); and the representative of 16SrVII-F was detected in the wild species Vernonia brasiliana. (Fugita et al. 2017). Specifically regarding subgroup 16SrVII-B, the reference phytoplasma of this subgroup was described from erigeron and periwinkle (Barros et al. 2002), while other members of this subgroup were reported in cauliflower (Pereira et al. 2016a) and ming aralia (Pereira et al. 2016b). The disease here studied is a threat since olive planting is in large expansion in Brazil. A potential control option could be use of propagative material from sources free of the pathogen. Based on our findings, olive tree represents a new host for subgroup 16SrVII-B phytoplasma, which is different from 16Sr groups previously reported as associated with olive witches’ broom in other countries.


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