Annalisa Giampetruzzi

Italian National Research Council | CNR · Institute for Sustainable Plant Protection

Xylella fastidiosa subspecies pauca strain “De Donno” (XfDD) ST53 is the agent of Olive Quick Decline Syndrome (OQDS), a severe disease firstly described in Apulia, Italy. Beside the high susceptibility of the two local cultivars Cellina di Nardò and Ogliarola salentina, traits of resistance to the bacterium were found in the cultivar Leccino. Prev...

The invasive plant pathogen Xylella fastidiosa currently threatens European flora through the loss of economically and culturally important host plants. This emerging vector-borne bacterium, native to the Americas, causes several important diseases in a wide range of plants including crops, ornamentals, and trees. Previously absent from Europe, and...

The emergence of Xylella fastidiosa in Europe revealed the occurrence of bacterial strains belonging to different subspecies and unraveled the vulnerability of some typical European plant species. Among these, olive was found infected in different European outbreaks, with infections caused by strains harboring different sequence types (STs) and bel...

Evidences from the Pierce's Disease suggest a major role of the plant cell wall in the mechanism of pathogenesis. In grapevine, Xylella knockout mutants of Cell Wall Degrading Enzymes-CWDE (polygalacturonase, endoglucanase) are impaired in movement and pathogenicity as they are unable to degrade cell wall middle lamellas of Pit Membranes (PMs), por...

The compelling search for a strategy to tackle Xylella fastidiosa strain 'De Donno' and the Olive Quick Decline Syndrome (OQDS) it causes in olive trees, led us to explore the possibility to identify potential biocontrol agents among the microbial communities naturally inhabiting xylem vessels of infected trees. To this aim, we pursued a multiappro...

Honeybees (Apis mellifera) provide pollination services that are crucial for food crops and agriculture. However, declines in insect pollinators, including honeybees, have raised concerns worldwide. Diseases and parasites are among the major factors affecting pollinator health. In particular, the devastating invasive parasitic mite (Varroa distruct...

The dynamics of Xylella fastidiosa infections in the context of the endophytic microbiome was studied in field-grown plants of the susceptible and resistant olive cultivars Kalamata and FS17. Whole metagenome shotgun sequencing (WMSS) coupled with 16S/ITS rRNA gene sequencing was carried out on the same trees at two different stages of the infectio...

In this study, we documented the complete coding genome sequence of a Black queen cell virus (BQCV) isolate from honey bees in Italy. This genome sequence illustrates a high similarity with other BQCV isolates reported worldwide and could provide insights into BQCV genome phylogeny and divergence.

Xylella fastidiosa is an economically important plant pathogenic bacterium of global importance associated, since 2013, with a devastating epidemic in olive trees in Italy. Since then, several outbreaks of this pathogen have been reported in other EU member countries including Spain, France and Portugal. In Spain, the three major subspecies (subsp....

Xylella fastidiosa is an economically important plant-pathogenic bacterium that has emerged as a pathogen of global importance associated with a devastating epidemic in olive trees in Italy associated with X. fastidiosa subspecies pauca and other outbreaks in Europe, such as X. fastidiosa subspecies fastidiosa and X. fastidiosa subspecies multiplex...

Olive quick decline syndrome (OQDS) is a devastating disease of olive trees in the Salento region, Italy. This disease is caused by the bacterium Xylella fastidiosa, which is widespread in the outbreak area; however, the "Leccino" variety of olives has proven to be resistant with fewer symptoms and lower bacterial populations than the "Ogliarola sa...

Numerous attempts have been made to test the use of endophytic bacteria to control diseases caused by Xylella fastidiosa (Xf), but promising results obtained in vitro have often proved inadequate once transferred to the field. A new encouraging possibility came from the observation that the bacterium Paraburkholderia phytofirmans PsJN, widely studi...

An increasing number of Xylella fastidiosa outbreaks associated with strains of the subspecies multiplex has been reported in southern Europe, currently the most common strains being detected in Corsica, the Balearic Islands, the province of Alicante (Spain) and, more recently, reported for the first time in Portugal and in the region of Tuscany (n...

Xylella fastidiosa (Xf) is continuing to emerge as a devastating bacterial pathogen for many economically relevant species. Xf subsp. pauca strain De Donno is associated with olive quick decline syndrome (OQDS), a destructive disease occurring in the southern area of Apulia (Italy). In susceptible olive cultivars, symptoms are characterised by init...

Olive quick decline syndrome (OQDS) is a devastating olive disease, which emerged few years ago in the region of Apulia (southern Italy) as a result of the bacterial infections caused by Xylella fastidiosa subsp. pauca. Bacterial infections were consistently associated with severe desiccations on the local cvs Cellina di Nardò and Ogliarola salenti...

Olive Quick Decline Disease (OQDS) is a devastating olive disease emerged few years ago in the region of Apulia (southern Italy) as a result of the bacterial infections caused by Xylella fastidiosa subsp. pauca. Bacterial infections were consistently associated to severe desiccations on the local cvs Cellina diNardò and Ogliarola salentina,whereas...

Xylella fastidiosastrain De Donno causes severe symptoms of desiccation on the susceptible cultivars Ogliarola salentina and Cellina di Nardò. In the Xylella-ravaged olive groves, survivor plants of cv Leccino have been identified and monitored since the beginning of epidemic spread of X. fastidiosain Apulia (southern Italy). Studies in field-grown...

Grapevine Pinot gris virus (GPGV) was initially discovered in Trentino, Italy where it was associated with symptoms of chlorotic mottling and leaf deformation (GLMD). Then, this virus was reported in all the main grape growing areas worldwide (Saldarelli et al. 2017), which is an indication of the dissemination of uncontrolled propagation materials...

La determinazione del profilo ionico di foglie sintomatiche e asintomatiche è stata effettuata su due cultivar di olivo che rispondono in maniera diversa all’infezione di Xylella fastidiosa. Lo studio ha lo scopo di esplorare i meccanismi coinvolti nello sviluppo dei sintomi e/o nell’interazione pianta patogeno.

Recenti investigazioni hanno mostrato l’efficacia del batterio Paraburkholderia phytofirmans PsJN nel ridurre gli effetti di Pierce’s Disease in vite. Il nostro studio intende verificare le possibilità di impiego di PsJN come agente di controllo biologico di X. fastidiosa, valutando le sue modalità di colonizzazione e persistenza in olivo e misuran...

Numerous research efforts are currently underway to identify novel biocontrol agentsfor the management of diseases associated with Xylella fastidiosa. Despite the encouraging premises, most of these studies proved unable to provide long-term effects or failed once they were examined at the field-scale. An intriguing exception was that of the rhizos...

The plant vascular system is the route of transport of mineral elements that play key roles in controlling a multitude of metabolic functions. The xylem colonizer Xylella fastidiosa, like any other endophyte, has enacted a series of strategies to compete with the host for mineral ions, and ensure its growth. Many of the strategies are linked to the...

The core microbiome has been increasingly recognized to be central to plant health. However, the extent to which host plant may play a role in shaping its core microbiome and their implications for host susceptibility/resistance to a particular disease, remains poorly understood. Such knowledge, besides providing insight on the potential role of co...

Diseases caused by Xylella fastidiosa are among the most destructive for several agricultural productions. A deadly disease of olive, termed olive quick decline syndrome, is one of the most recent examples of the severe impacts caused by the introduction and spread of this bacterium in new ecosystems with favorable epidemiological conditions. Decip...

An outbreak of Xylella fastidiosa was discovered in late 2018 in northern Italy affecting several plant species. Multilocus sequence typing analyses detected the presence of strains clustering in X. fastidiosa subsp. multiplex and harboring a hitherto uncharacterized sequence type, ST87. Three cultured strains (TOS4, TOS5, and TOS14) were subjected...

Resistance-breaking (RB) strains constitute a clade of biological and genetically distinct isolates of Citrus tristeza virus (CTV) that replicate and move systemically in Poncirus trifoliata (trifoliate orange), resistant to other known strains of CTV. Molecular markers have been developed by comparative genome analysis to allow quick identificatio...

The continuous losses of honey bee colonies have encouraged further investigation on honey bee infecting viruses. In 2017 and 2018, we investigated the presence of honey bee viruses in more than 35 apiaries located in Puglia region. RNA was extracted from a pool of 10 adult bees collected in each apiary then tested by RT-PCR.

An outbreak of Xylella fastidiosa subsp. multiplex sequence type ST6 was discovered in 2017 in mainland Spain affecting almond trees. Two cultured almond strains, "ESVL" and "IVIA5901," were subjected to high throughput sequencing and the draft genomes assembled. Phylogenetic analysis conclusively indicated they belong to the subspecies multiplex,...

A dramatic outbreak of Xylella fastidiosa decimating olive was discovered in 2013 in Apulia, Southern Italy. This pathogen is a quarantine bacterium in the European Union (EU) and created unprecedented turmoil for the local economy and posed critical challenges for its management. With the new emerging threat to susceptible crops in the EU, efforts...

Field observations carried out in Salento (Italy) in the area infected by Xylella fastidiosa (Xf) evidenced that olive trees of the cultivar 'Leccino' show milder symptoms, if compared to those observed in the susceptible cv. 'Ogliarola salentina'. A transcriptome profiling of the two cultivars infected with the Xf De Donno strain revealed differen...

Microbial endophytes are well known to protect host plants against pathogens, thus representing a promising strategy for the control of Xylella fastidiosa in olive trees. Although their high potential for being used as biocontrol agents, there are pending questions regarding to which extent endophytes enhance plant defences. For example, how microb...

We report the complete annotated genome sequence of the plant-pathogenic bacterium Xylella fastidiosa subsp. fastidiosa strain IVIA5235. This strain was recovered from a cherry tree in Mallorca, Spain.

Quick decline caused by Citrus tristeza virus (CTV) destroyed citrus on sour orange rootstock in southern California during the 1930’s -40’s. However, use of resistant/tolerant CTV rootstocks, certified pathogen-free budwood, and quarantines have limited further economic damage from CTV. Multi-locus marker profiles of California CTV isolates reveal...

Xylella fastidiosa (Xf) is a xylem-limited bacterial plant pathogen that is responsible for Olive Quick Decline Syndrome (OQDS), a devastating disease reported in Salento (Apulia, Italy). Field observations show that olive cv. ‘Leccino’ show milder symptoms when compared to the highly susceptible cv. ‘Ogliarola’. A prior transcriptome analysis of ‘...

Strain differentiating marker profiles of citrus tristeza virus (CTV) isolates from California have shown the presence of multiple genotypes. To better define the genetic diversity involved, full-length genome sequences from four California CTV isolates were determined by small-interfering RNA sequencing. Phylogenetic analysis and nucleotide sequen...

A protocol is described to purify small (s)RNA molecules from tissues of grapevine and other woody plants. The protocol has been specifically developed to analyze sRNA populations by high-throughput sequencing. It has been widely used on species of the genera Prunus and Vitis particularly rich in polyphenols and other enzyme-inhibiting compounds. T...

Xylella fastidiosa (Xf) subsp. pauca phylotype ST53 is responsible for a devastating disease on olive crops, in the southern area of Apulia (Italy). Despite the vast literature available on Xf-host relationships, scarce and barely recent efforts have been made to investigate the potential role of microbial interactions on the disease phenotype of X...

A multi-factorial strategy is required to co-exist with X. fastidiosa infections, which are devastating olive trees in the southern area of Apulia (Italy). Observations in the outbreak area can provide information on potential approaches for containment. Olive cvs Leccino and FS17 show lessened symptoms and host lower bacterial populations (1,2) th...

X. fastidiosa subsp. pauca causes diseases in citrus and olive plants. Fortunately, there are citrus species and olive varieties more tolerant to X. fastidiosa and therefore good genotypes to search for genetic sources of resistance. Following this approach, global gene expression analyses were recently achieved using Citrus reticulata cv. Ponkan a...

While different sources of natural resistance to X. fastidiosa have been described in grapevines and citrus, lack of solid information exists on possible sources of resistance/tolerance in the cultivars that characterize the wide olive germplasm. Preliminary field observations and laboratory analyses of a few cultivars, have shown that differential...

A devastating outbreak of a strain of Xylella fastidiosa is ravaging the olive trees of southern Puglia, Italy (Saponari et al., 2015). The bacterium, discovered in 2013, causes the Olive Quick Decline Syndrome (OQDS), a destructive disease characterized by apical and marginal leaf scorching, extensive branch and twig dieback, followed by death of...

A strain of Xylella fastidiosa is ravaging the olive trees of Southern Apulia, Italy (Saponari et al., 2013). The bacterium causes the Olive Quick Decline Syndrome (OQDS), a disease showing symptoms of apical and marginal leaf scorching, extensive branch and twig dieback and death of the trees (Martelli et al., 2016). Transmission tests demonstrate...

The application of high-throughput sequencing (HTS) in plant virology research had an immense influence on our perspective of disease etiology. The technology opened a new avenue of exploration that is unbiased and at an unparalleled level of sensitivity. Initially, HTS was used for virus discovery with the greatest success up until now being the d...

We report here the complete and annotated genome sequence of the plant-pathogenic bacterium Xylella fastidiosa subsp. pauca strain De Donno. This strain was recovered from an olive tree severely affected by olive quick decline syndrome (OQDS), a devastating olive disease associated with X. fastidiosa infections in susceptible olive cultivars.

Xylella fastidiosa (Xf) is a xylem-limited bacterium, regulated as a quarantine pest, that is causing a devastating disease on olive crops, in the southern area of Apulia (Italy). Its potential spread in the Mediterranean area poses a severe threat to EU agriculture and landscape environment. Despite the vast literature on Xf relationships with hos...

Xylella fastidiosa is a plant pathogenic bacterium recently introduced in Europe that is causing decline in olive trees in the South of Italy. Genetic studies have consistently shown that the bacterial genotype recovered from infected olive trees belongs to the sequence type ST53 within subspecies pauca. This genotype, ST53, has also been reported...

Osservazioni e rilievi di campo integrati da un programma di campionamenti e saggi diagnostici di laboratorio confermano in alcune delle varietà oggetto di studio una minore incidenza delle infezioni di Xylella fastidiosa, a cui sono associate sintomatologie di deperimento e manifestazioni di disseccamento più lievi e attenuate rispetto a quanto os...

Most Citrus tristeza virus (CTV) isolates in California are biologically mild and symptomless in commercial cultivars on CTV tolerant rootstocks. However, to better define California CTV isolates showing divergent serological and genetic profiles, selected isolates were subjected to deep sequencing of small RNAs. Full-length sequences were assemble...

Figure S1. Sixteen multiplex families included in the linkage study, the red bars represent 146 genotyped subjects. Figure S2. Plot of LOD score statistics from NPL analysis for the chromosomes in which the score exceeded the 1.5 level. Figure S3. Pedigrees included in the exome sequencing study. Figure S4. Number of variants called by Unified G...

A quince tree showing severe symptoms of a previously undescribed viral disease occurring in northern Apulia (Italy) was analysed using high-throughput sequencing of small RNA libraries, leading to the identification of a new strain of apple green crinkle associated virus (isolate AGCaV-CYD) showing peculiar traits. RT-PCR with specific primers det...

The recent findings of the plant pathogenic bacterium Xylella fastidiosa (Xf), infecting several plant species in Italy and France, raised major concerns for its potential impact on the EU and Mediterranean agriculture. In the current EU outbreaks, olive is the predominantly affected crop, in which the bacterium has been consistently associated wit...

The CoDiRO strain of Xylella fastidiosa (Xf), which is devastating olive trees in the Apulia Region (southern Italy), represents the first documented establishment of this plant pathogenic bacterium in Europe. Diseases induced by Xf have no chemical cure and its pathogenic mechanism(s) are not completely understood. Nevertheless, profiles and relat...

Olive Quick Decline Syndrome (OQDS) is a destructive disease of olive (Olea europaea) described in Apulia (Italy), to which the CoDiRO strain of Xylella fastidiosa subsp. pauca (Xfp) is associated. Differently from the severely affected cv. Ogliarola salentina, Xfp-infected plants of the cv. Leccino develop reduced symptoms, which are compatible wi...

Following the introduction and establishment of the plant pathogenic bacterium Xylella fastidiosa (Xf) in the Apulia Region (southern Italy), olive turned to be the main host of the Salentinian bacterial strain and the majorly devastated crop. The mechanism of pathogenicity of Xf is still not completely understood and no means to cure the bacterium...

The CoDiRO strain of Xylella fastidiosa subsp. pauca (Xfp) is ravaging olive (Olea europaea) groves in southern Italy, causing a destructive disease denoted Olive Quick Decline Syndrome (OQDS). Field observations show that the Xfp-infected plants of the cv. Ogliarola salentina develop more severe symptoms than that of cv. Leccino. A global transcri...

The sRNAs libraries from young stem bark of Hamlin sweet orange grafted on sour orange inoculated with a VT or a T30 CTV genotype were compared with mirBase database of Citrus, Arabidospis thaliana and Nicotiana benthamiana, allowing to identify 12 miRNAs from six different conserved families.

Background IgA nephropathy (IgAN) is a common complex disease with a strong genetic involvement. We aimed to identify novel, rare, highly penetrant risk variants combining family‐based linkage analysis with whole‐exome sequencing (WES). Methods Linkage analysis of 16 kindreds of South Italian ancestry was performed using an ‘affected‐only’ strateg...

Following the introduction and establishment of the plant pathogenic bacterium Xylella fastidiosa (Xf) in the Apulia Region (southern Italy), olive turned to be the main host of the Salentinian bacterial strain and the majorly devastated crop. The mechanism of pathogenicity of Xf is still not completely understood and no means to cure the bacterium...

The CoDiRO strain of Xylella fastidiosa subsp. pauca (Xfp) is ravaging olive (Olea europaea) groves in southern Italy, causing a destructive disease denoted Olive Quick Decline Syndrome (OQDS). Field observations show that the Xfp-infected plants of the cv. Ogliarola salentina develop more severe symptoms than that of cv. Leccino. A global transcri...

The recent findings of the plant pathogenic bacterium Xylella fastidiosa (Xf), infecting several plant species in Italy and France, raised major concerns for its potential impact on the EU and Mediterranean agriculture. In the current EU outbreaks, olive is the predominantly affected crop, in which the bacterium has been consistently associated wit...

Background The recent Xylella fastidiosa subsp. pauca (Xfp) outbreak in olive (Olea europaea) groves in southern Italy is causing a destructive disease denoted Olive Quick Decline Syndrome (OQDS). Field observations disclosed that Xfp-infected plants of cv. Leccino show much milder symptoms, than the more widely grown and highly susceptible cv. Ogl...

Grapevine Pinot gris virus (GPGV) is a new virus reported in Europe and several other grape-growing countries. In an attempt to identify a vector for GPGV, samples of the eriophyid mite Colomerus vitis collected from buds and erinea in GPGV-infected vines were analysed by RT-PCR, using specific primers. Molecular analysis revealed the presence of G...

A novel virus has been identified by next generation sequencing (NGS) in privet (Ligustrum japonicum L.) affected by a graft-transmissible disease characterized by leaf blotch symptoms resembling infectious variegation, a virus-like privet disease with an unclear etiology. Such a virus, which has been tentatively named privet leaf blotch-associated...

A devastating outbreak of a strain of Xylella fastidiosa is ravaging the olive trees of southern Puglia, Italy (Saponari et al., 2015). The bacterium, discovered in 2013, causes the Olive Quick Decline Syndrome (OQDS), a destructive disease characterized by apical and marginal leaf scorching, extensive branch and twig dieback, followed by death of...

The complete nucleotide sequence and genome organization of a new Badnavirus isolated from the autochthonous grapevine variety "Bombino nero" from Apulia (Italy) was determined. The genome of this virus consists of 7097 nt and has four open reading frames (ORFs). Analysis of putative proteins encoded by each ORF revealed greatest sequence similarit...

The draft genome sequence of Xylella fastidiosa CO33 isolate, retrieved from symptomatic leaves of coffee plant intercepted in northern Italy, is reported. The CO33 genome size is 2,681,926 bp with a GC content of 51.7%.

The use of NGS approach allowed the identification and the complete genome characterization of several plant virus species, previously unknown (Persimmon cryptic virus, PeCV; Mulberry badnavirus-1, MBV-1), or scarcely characterized and never associated to a specific symptomatology and/or host (Persimmon rhabdovirus A, PeVA; Apple green crinkle asso...

For a thorough characterization of their virome, 20 selected clones of grapevine cultivars and rootstocks, maintained in the premultiplication plots of the CRSFA (Centro di Ricerca, Sperimentazione e Formazione in Agricoltura “Basile Caramia”, Locorotondo, Italy), were subjected to high throughput sequencing (HTS). Prior to the present study, which...

Vegetative propagation of grapevines favours the perpetuation and dissemination in nature, of intracellular pathogens (over than 70 considering viruses, viroids and phytoplasmas). Once in the field, their presence may affect in various ways the plant's yield and its quality. Preventing infection spreading through a prompt identification, characteri...

In 2014, some registered native grapevine cultivars from Apulia were analyzed to determine their "absolute" sanitary status (virome) i.e. the totality of virus, viroids and phytoplasmas, present in any single accession, using a high throughput sequencing (HTS) approach (Giampetruzzi et al., 2015). Small RNA libraries synthesized from a symptomless...