Epigenetic Changes and Transcriptional Reprogramming Upon Woody Plant Grafting for Crop Sustainability in a Changing Environment.

Plant grafting is an ancient agricultural practice widely employed in crops such as woody fruit trees, grapes, and vegetables, in order to improve plant performance. Successful grafting requires the interaction of compatible scion and rootstock genotypes. This involves an intricate network of molecular mechanisms operating at the graft junction and associated with the development and the physiology of the scion, ultimately leading to improved agricultural characteristics such as fruit quality and increased tolerance/resistance to abiotic and biotic factors.

Structural Diversity and Highly Specific Host-Pathogen Transcriptional Regulation of Defensin Genes Is Revealed in Tomato.

Defensins are small and rather ubiquitous cysteine-rich anti-microbial peptides. These proteins may act against pathogenic microorganisms either directly (by binding and disrupting membranes) or indirectly (as signaling molecules that participate in the organization of the cellular defense). Even though defensins are widespread across eukaryotes, still, extensive nucleotide and amino acid dissimilarities hamper the elucidation of their response to stimuli and mode of function.

Hex1, the Major Component of Woronin Bodies, Is Required for Normal Development, Pathogenicity, and Stress Response in the Plant Pathogenic Fungus .

Woronin bodies are membrane-bound organelles of filamentous ascomycetes that mediate hyphal compartmentalization by plugging septal pores upon hyphal damage. Their major component is the peroxisomal protein Hex1, which has also been implicated in additional cellular processes in fungi. Here, we analyzed the Hex1 homolog of , an important asexual plant pathogen, and we report its pleiotropic involvement in fungal growth, physiology, stress response, and pathogenicity.

A Pesticide Residues Insight on Honeybees, Bumblebees and Olive Oil after Pesticidal Applications against the Olive Fruit Fly (Diptera: Tephritidae).

In 2017 and 2018, a field survey was initiated on Greek olive orchards to investigate the attractiveness of bait spray applications and the impact of cover and bait sprays applied against the olive fruit fly (Diptera: Tephritidae), on the honeybee, L. and bumblebees , by investigating the pesticides' residual prevalence. Bee colonies were evenly distributed in three sites located on coastal areas of Western Crete and visited almost weekly between July and October.

New Distribution and Molecular Diversity of the Reniform Nematode (Nematoda: Rotylenchulinae) in Europe.

Reniform nematodes of the genus are semi-endoparasites of numerous herbaceous and woody plant species roots and occur largely in regions with temperate, subtropical, and tropical climates. In this study, we provide new records of the nematode in eight European countries (Czech Republic, France, Germany, Hungary, Italy, Romania, Serbia, and Portugal), in addition to the six Mediterranean countries (Greece, Israel, Jordan, Spain, Syria, and Turkey) where the nematode was previously reported. Four new host species (corn, pea, wheat, and an almond-peach hybrid rootstock) are added to the recorded host species (bean, chickpea, hazelnut, peanut, soybean, and wild and cultivated olive).

The Cypriot Indigenous Grapevine Germplasm Is a Multi-Clonal Varietal Mixture.

Cypriot vineyards are considered as one among the earliest niches of viticulture and a pivotal hub for the domestication and dissemination of grapevine. The millennial presence of spp. in this Eastern Mediterranean island has given rise to a plethora of biotypes that have not been adequately characterized, despite their unique attributes and stress tolerance.

Compatibility of fluazaindolizine and oxamyl with on spore attachment to juveniles of and .

Fluazaindolizine is a novel sulfonamide nematicide that is the active ingredient (a.i.) of Salibro™, a.

Arbuscular mycorrhizal fungus inocula from coastal sand dunes arrest olive cutting growth under salinity stress.

Cultivation of olive trees covers large coastal areas of land in Mediterranean regions, many of them characterized by low soil fertility and exposed to salinity and seasonal drought. In this frame, we developed mixed community inocula of arbuscular mycorrhizal fungi (AMF) derived from the extreme, seasonally arid environments of six Mediterranean sand dunes and evaluated their effects, in the form of community inocula, on rooted semi-woody olive tree cuttings (Olea europaea cv. Koroneiki).

Stomatal behavior following mid- or long-term exposure to high relative air humidity: A review.

High relative air humidity (RH ≥ 85%) is frequent in controlled environments, and not uncommon in nature. In this review, we examine the high RH effects on plants with a special focus on stomatal characters. All aspects of stomatal physiology are attenuated by elevated RH during leaf expansion (long-term) in C species.

Identification and functional characterization of a novel acetyl-CoA carboxylase mutation associated with ketoenol resistance in Bemisia tabaci.

Insecticides of the tetronic/tetramic acid family (cyclic ketoenols) are widely used to control sucking pests such as whiteflies, aphids and mites. They act as inhibitors of acetyl-CoA carboxylase (ACC), a key enzyme for lipid biosynthesis across taxa. While it is well documented that plant ACCs targeted by herbicides have developed resistance associated with mutations at the carboxyltransferase (CT) domain, resistance to ketoenols in invertebrate pests has been previously associated either with metabolic resistance or with non-validated candidate mutations in different ACC domains.

Epigenetics: possible applications in climate-smart crop breeding.

To better adapt transiently or lastingly to stimuli from the surrounding environment, the chromatin states in plant cells vary to allow the cells to fine-tune their transcriptional profiles. Modifications of chromatin states involve a wide range of post-transcriptional histone modifications, histone variants, DNA methylation, and activity of non-coding RNAs, which can epigenetically determine specific transcriptional outputs. Recent advances in the area of '-omics' of major crops have facilitated identification of epigenetic marks and their effect on plant response to environmental stresses.

The Role of Proteases in Determining Stomatal Development and Tuning Pore Aperture: A Review.

Plant proteases, the proteolytic enzymes that catalyze protein breakdown and recycling, play an essential role in a variety of biological processes including stomatal development and distribution, as well as, systemic stress responses. In this review, we summarize what is known about the participation of proteases in both stomatal organogenesis and on the stomatal pore aperture tuning, with particular emphasis on their involvement in numerous signaling pathways triggered by abiotic and biotic stressors. There is a compelling body of evidence demonstrating that several proteases are directly or indirectly implicated in the process of stomatal development, affecting stomatal index, density, spacing, as well as, size.

Genetic Diversity and Structure Analysis Assessed by SSR Markers in a Large Collection of Vitis Cultivars from the Island of Crete, Greece.

The grape (Vitis vinifera L.) cultivars in the island of Crete, Greece represent one of the oldest populations of the species; nevertheless, very scarce information is available about its genetic structure. In this study, Vitis cultivars collected from the island of Crete were characterized using microsatellite markers.

Polyamine homeostasis in tomato biotic/abiotic stress cross-tolerance.

Adverse conditions and biotic strain can lead to significant losses and impose limitations on plant yield. Polyamines (PAs) serve as regulatory molecules for both abiotic/biotic stress responses and cell protection in unfavourable environments. In this work, the transcription pattern of 24 genes orchestrating PA metabolism was investigated in Cucumber Mosaic Virus or Potato Virus Y infected and cold stressed tomato plants.

First report of cultivated Cretan mountain tea () as a host of and in Crete, with some additional records on the occurrence of species in Greece.

Cultivated Cretan mountain tea or Malotira ( L.) was found to be infected by and in the island of Crete. The authors provide the first molecular characterization of in Greece and the first report of Cretan mountain tea or Malotira as a host of species worldwide.

The evolution of multiple-insecticide resistance in UK populations of tomato leafminer, Tuta absoluta.

Background: The tomato leafminer, Tuta absoluta, is an economically important pest of tomatoes in Europe, Africa, Asia and South America. In the UK this species is controlled using an integrated pest management (IPM) programme which incorporates the insecticides spinosad and chlorantraniliprole. In response to UK grower concerns of loss of efficacy of these compounds at certain sites, insecticide bioassays were performed on five populations collected from four commercial glasshouses and potential mechanisms of resistance investigated.

Genotype-dependent regulation of vitamin E biosynthesis in olive fruits as revealed through metabolic and transcriptional profiles.

Vitamin E is a general term used to describe a group of eight lipophilic compounds known as tocochromanols. These vitamin E variants are chemically categorised into two classes formed by α-, β-, γ- and δ- tocopherols and tocotrienols isoforms, respectively. The present study describes the concurrent regulation of genes and metabolites orchestrating vitamin E biosynthesis in olive drupes of five distinctive Greek olive cultivars.

First Report of , , and in Association with Cultivated and Wild Olives in Crete, Greece and Molecular Identification of and .

Nematode samplings in cultivated and wild olive in Crete, Greece, yielded the presence of Bitylenchus hispaniensis , Helicotylenchus microlobus , Helicotylenchus vulgaris , Merlinius brevidens , and Pratylenchoides alkani . With the exception of H. microlobus and M.

Hydrogen Sulfide: A Potent Tool in Postharvest Fruit Biology and Possible Mechanism of Action.

Hydrogen sulfide (HS), an endogenous gaseous molecule, is considered as a signaling agent, in parallel with other low molecular weight reactive substances, mainly hydrogen peroxide (HO) and nitric oxide (NO), in various plant systems. New studies are now revealing that the postharvest application of HS, through HS donors such as sodium hydrosulfide (NaSH) or sodium sulfide (NaS), can inhibit fruit ripening and senescence programs in numerous fruits. We discuss here current knowledge on the impact of HS in postharvest physiology of several climacteric and non-climacteric fruits such as banana, apple, pear, kiwifruit, strawberry, mulberry fruit, and grape.

Identification and Seasonal Abundance of Auchenorrhyncha With a Focus on Potential Insect Vectors of Xylella fastidiosa in Olive Orchards in Three Regions of Greece.

Studies of the species composition, seasonal appearance, and abundance of Auchenorrhyncha in olive crops is of paramount importance to reduce the potential of Xylella fastidiosa to invade new areas. As similar investigations had not previously been conducted in Greece, extensive surveys were undertaken in olive orchards located in three of the most important regions for olive production in central Greece (Fthiotida), south-central Greece (Attica), and southern Greece (Chania). Surveys took place over a 13-mo period, using Malaise traps examined on a monthly basis.

Molecular characterization of pyrethroid resistance in the olive fruit fly Bactrocera oleae.

Α reduction of pyrethroid efficacy has been recently recorded in Bactrocera oleae, the most destructive insect of olives. The resistance levels of field populations collected from Crete-Greece scaled up to 22-folds, compared to reference laboratory strains. Sequence analysis of the IIS4-IIS6 region of para sodium channel gene in a large number of resistant flies indicated that resistance may not be associated with target site mutations, in line with previous studies in other Tephritidae species.

Morphological and Molecular Identification of and from the Rhizosphere of Grapevine and Banana in Greece.

Plant-parasitic nematodes such as and are species widely distributed in central Europe as well as in Mediterranean area. In Greece, both species have been previously reported but no morphometrics or molecular data were available for these species. Nematode surveys in the rhizosphere of grapevines in Athens carried out in 2016 and 2017, yielded a species identified as .