Dissecting the transcriptional regulatory network of seed and mesocarp development in peach

Peach (Prunus persica) is one of the most important fleshy fruit crops worldwide and model species for drupe plant species. Peach fruit development is characterized by a tight relationship between seed and pericarp during the early stages, followed in later stages by an uncoupling in the pattern of development due to the lignification of the endocarp. Diverse peach cultivars may have fruit developmental periods of very different length, while having a similar development for the seed. Understanding the relationship between seed and pericarp sheds light onto the mechanism regulating fruit development. Transcriptomic approach is a powerful tool to investigate this relationship, as it gives broad information on the transcription of a large amount of genes in a single experiment. Chapter II is a published article regarding the use of the µPEACH1.0 array for the understanding of the relationships between seed and mesocarp and between early and late stages of development in the cultivar Fantasia. Peach mRNA samples were taken from early and late developmental stages of the two organs and then hybridized on the 4 806 probes of the µPEACH1.0 array. The transcriptomic data obtained from these samples were then cross-compared. Marker genes for the four peach developmental stages (S1 stage: fruit cells division and enlargement, S2: lignification of the endocarp, S3: mesocarp cell expansion, S4: ripening) were found for both mesocarp and seed and their expression confirmed by qRT-PCR. Stage- specific markers found for the mesocarp were a RD22-like protein, a serin- carboxypeptidase, a senescence-related protein and an Aux/IAA, for S1, S2, S3 and S4 stages, respectively, while seed markers were a lipid transfer protein(LTP1), a pathogenesis-related (PR) protein, a prunin and Late Embryogenesis Abundant (LEA) protein, for S1, S2, S3 and S4 stages, respectively. By qRT-PCR it was confirmed that these genes act as markers also in an early cultivar (SpringCrest) and a slow ripening genotype (slr). Then, the data were analyzed with the HORMONOMETER tool in order to indirectly measure the relative amounts of hormones in the different organs and developmental stages. It was found that auxins, cytokinins, and gibberellins may be involved in signaling during the early development, when there is cross-talk between the two organs. Chapter III is an unpublished article in which it is described how a new microarray platform, µPEACH3.0, was employed to study peach mesocarp and seed development. The recent publication of the peach genome allowed the development of a whole-genome microarray which overcame the problem of having an array assessing gene expression of only one part of the genome. In respect of the study described in Chapter II, also the number of samples were increased: three biological replicates for each of six time-points for each of the two organs were used, giving a larger overview on the development of these two tissues. The whole genome microarray, µPEACH3.0, performed well, with a correlation with qRT-PCR data of 0.77, a number similar to that found for other arrays. The transcriptomic data easily distinguished the two tissues and the six time-points, as shown by principal component analysis. 69% of the probes gave a significant signal from at least one of the samples. Anyway, considering that the number of functioning probes diminishes if only the samples of one tissue are taken into account, it is probable that testing the microarray with mRNA coming from other tissues (such as leaves or roots) will increase the number of significant signals coming from the array. Global analysis of gene activity was focused into the early stages of development. Data allowed us to identify several genes involved in cell cycle processes that occur at the onset of both mesocarp and seed development. In particular genes of the TITAN family were found to be active in the endosperm containing seed. The analysis of the cell cycle genes in the mesocarp showed the existence of two different patterns of expression: while mitosis related genes were expressed only in stage S1, DNA replication genes showed a double peak of expression, in S1 and then in S3/S4, suggesting that events of endoreduplication may occur in these late stages. By qRT-PCR the expression levels of these genes were tested also in other cultivars, the data obtained suggest that the lack of endoreduplication may be involved in the slow rate of growth in S3 stage of the slr genotype. The patterns of expression of transcription factors (TFs) families were then assessed, as transcription factors are thought to be the proteins with the most important regulatory roles during development. It was found that TFs of the SQUAMOSA promoter Binding Protein (SBP) family have an high expression level at the beginning of the development of both the organs considered, which then quickly decreases. The transcription of Growth Regulating Factors (GRFs) has been discovered to be induced in the mature seed. The data were confirmed by qRT-PCR also in an ‘SpringCrest’ and the slow ripening genotype slr. Given that the mRNA abundance of genes belonging to these TFs families is regulated by specific microRNAs (miRNAs) in other plant species, the expression of the peach homologues of these miRNAs was measured. In three different cultivars a negative correlation in the RNA abundance was found for the following miRNA/target TF couples: miR156/SBP, miR396/GRF and mir167/ARF8, suggesting not only that these miRNAs have the same activity also in peach, but also that miRNAs are deeply involved in the regulatory network underlying the peach fruit development. Appendix is a published study in which µPEACH3.0 is used to study the effects of wounding in two peach cultivars with different tolerance to this stress. RNA samples from wounded and unwounded mesocarps of melting cultivar Glohaven (GH) and slow melting cultivar BigTop (BT) were used. Transcriptomic data, confirmed by qRT-PCR analysis, showed the involvement of WRKY, AP2/ERF and HSP20 transcription factors in the GH response to wounding. Along with them, also genes involved in response to stresses, cell wall metabolism, phenilpropanoid and triterpenoid biosynthesis were found to be up regulated in the wounded GH mesocarp

A microarray approach to identify genes involved in seed-pericarp cross-talk and development in peach

<p>Abstract</p> <p>Background</p> <p>Field observations and a few physiological studies have demonstrated that peach embryogenesis and fruit development are tightly coupled. In fact, attempts to stimulate parthenocarpic fruit development by means of external tools have failed. Moreover, physiological disturbances during early embryo development lead to seed abortion and fruitlet abscission. Later in embryo development, the interactions between seed and fruit development become less strict. As there is limited genetic and molecular information about seed-pericarp cross-talk and development in peach, a massive gene approach based on the use of the μPEACH 1.0 array platform and quantitative real time RT-PCR (qRT-PCR) was used to study this process.</p> <p>Results</p> <p>A comparative analysis of the transcription profiles conducted in seed and mesocarp (cv Fantasia) throughout different developmental stages (S1, S2, S3 and S4) evidenced that 455 genes are differentially expressed in seed and fruit. Among differentially expressed genes some were validated as markers in two subsequent years and in three different genotypes. Seed markers were a LTP1 (lipid transfer protein), a PR (pathogenesis-related) protein, a prunin and LEA (Late Embryogenesis Abundant) protein, for S1, S2, S3 and S4, respectively. Mesocarp markers were a RD22-like protein, a serin-carboxypeptidase, a senescence related protein and an Aux/IAA, for S1, S2, S3 and S4, respectively.</p> <p>The microarray data, analyzed by using the HORMONOMETER platform, allowed the identification of hormone-responsive genes, some of them putatively involved in seed-pericarp crosstalk. Results indicated that auxin, cytokinins, and gibberellins are good candidates, acting either directly (auxin) or indirectly as signals during early development, when the cross-talk is more active and vital for fruit set, whereas abscisic acid and ethylene may be involved later on.</p> <p>Conclusions</p> <p>In this research, genes were identified marking different phases of seed and mesocarp development. The selected genes behaved as good seed markers, while for mesocarp their reliability appeared to be dependent upon developmental and ripening traits. Regarding the cross-talk between seed and pericarp, possible candidate signals were identified among hormones.</p> <p>Further investigations relying upon the availability of whole genome platforms will allow the enrichment of a marker genes repertoire and the elucidation of players other than hormones that are involved in seed-pericarp cross-talk (i.e. hormone peptides and microRNAs).</p

Evidence for the Band-Edge Exciton of CuInS2 Nanocrystals Enables Record Efficient Large-Area Luminescent Solar Concentrators

AbstractTernary I‐III‐VI2 nanocrystals (NCs), such as CuInS2, are receiving attention as heavy‐metals‐free materials for solar cells, luminescent solar concentrators (LSCs), LEDs, and bio‐imaging. The origin of the optical properties of CuInS2 NCs are however not fully understood. A recent theoretical model suggests that their characteristic Stokes‐shifted and long‐lived luminescence arises from the structure of the valence band (VB) and predicts distinctive optical behaviours in defect‐free NCs: the quadratic dependence of the radiative decay rate and the Stokes shift on the NC radius. If confirmed, this would have crucial implications for LSCs as the solar spectral coverage ensured by low‐bandgap NCs would be accompanied by increased re‐absorption losses. Here, by studying stoichiometric CuInS2 NCs, it is revealed for the first time the spectroscopic signatures predicted for the free band‐edge exciton, thus supporting the VB‐structure model. At very low temperatures, the NCs also show dark‐state emission likely originating from enhanced electron‐hole spin interaction. The impact of the observed optical behaviours on LSCs is evaluated by Monte Carlo ray‐tracing simulations. Based on the emerging device design guidelines, optical‐grade large‐area (30×30 cm2) LSCs with optical power efficiency (OPE) as high as 6.8% are fabricated, corresponding to the highest value reported to date for large‐area devices

Dissecting the transcriptional regulatory network of seed and mesocarp development in peach

Peach (Prunus persica) is one of the most important fleshy fruit crops worldwide and model species for drupe plant species. Peach fruit development is characterized by a tight relationship between seed and pericarp during the early stages, followed in later stages by an uncoupling in the pattern of development due to the lignification of the endocarp. Diverse peach cultivars may have fruit developmental periods of very different length, while having a similar development for the seed. Understanding the relationship between seed and pericarp sheds light onto the mechanism regulating fruit development. Transcriptomic approach is a powerful tool to investigate this relationship, as it gives broad information on the transcription of a large amount of genes in a single experiment. Chapter II is a published article regarding the use of the µPEACH1.0 array for the understanding of the relationships between seed and mesocarp and between early and late stages of development in the cultivar Fantasia. Peach mRNA samples were taken from early and late developmental stages of the two organs and then hybridized on the 4 806 probes of the µPEACH1.0 array. The transcriptomic data obtained from these samples were then cross-compared. Marker genes for the four peach developmental stages (S1 stage: fruit cells division and enlargement, S2: lignification of the endocarp, S3: mesocarp cell expansion, S4: ripening) were found for both mesocarp and seed and their expression confirmed by qRT-PCR. Stage- specific markers found for the mesocarp were a RD22-like protein, a serin- carboxypeptidase, a senescence-related protein and an Aux/IAA, for S1, S2, S3 and S4 stages, respectively, while seed markers were a lipid transfer protein(LTP1), a pathogenesis-related (PR) protein, a prunin and Late Embryogenesis Abundant (LEA) protein, for S1, S2, S3 and S4 stages, respectively. By qRT-PCR it was confirmed that these genes act as markers also in an early cultivar (SpringCrest) and a slow ripening genotype (slr). Then, the data were analyzed with the HORMONOMETER tool in order to indirectly measure the relative amounts of hormones in the different organs and developmental stages. It was found that auxins, cytokinins, and gibberellins may be involved in signaling during the early development, when there is cross-talk between the two organs. Chapter III is an unpublished article in which it is described how a new microarray platform, µPEACH3.0, was employed to study peach mesocarp and seed development. The recent publication of the peach genome allowed the development of a whole-genome microarray which overcame the problem of having an array assessing gene expression of only one part of the genome. In respect of the study described in Chapter II, also the number of samples were increased: three biological replicates for each of six time-points for each of the two organs were used, giving a larger overview on the development of these two tissues. The whole genome microarray, µPEACH3.0, performed well, with a correlation with qRT-PCR data of 0.77, a number similar to that found for other arrays. The transcriptomic data easily distinguished the two tissues and the six time-points, as shown by principal component analysis. 69% of the probes gave a significant signal from at least one of the samples. Anyway, considering that the number of functioning probes diminishes if only the samples of one tissue are taken into account, it is probable that testing the microarray with mRNA coming from other tissues (such as leaves or roots) will increase the number of significant signals coming from the array. Global analysis of gene activity was focused into the early stages of development. Data allowed us to identify several genes involved in cell cycle processes that occur at the onset of both mesocarp and seed development. In particular genes of the TITAN family were found to be active in the endosperm containing seed. The analysis of the cell cycle genes in the mesocarp showed the existence of two different patterns of expression: while mitosis related genes were expressed only in stage S1, DNA replication genes showed a double peak of expression, in S1 and then in S3/S4, suggesting that events of endoreduplication may occur in these late stages. By qRT-PCR the expression levels of these genes were tested also in other cultivars, the data obtained suggest that the lack of endoreduplication may be involved in the slow rate of growth in S3 stage of the slr genotype. The patterns of expression of transcription factors (TFs) families were then assessed, as transcription factors are thought to be the proteins with the most important regulatory roles during development. It was found that TFs of the SQUAMOSA promoter Binding Protein (SBP) family have an high expression level at the beginning of the development of both the organs considered, which then quickly decreases. The transcription of Growth Regulating Factors (GRFs) has been discovered to be induced in the mature seed. The data were confirmed by qRT-PCR also in an ‘SpringCrest’ and the slow ripening genotype slr. Given that the mRNA abundance of genes belonging to these TFs families is regulated by specific microRNAs (miRNAs) in other plant species, the expression of the peach homologues of these miRNAs was measured. In three different cultivars a negative correlation in the RNA abundance was found for the following miRNA/target TF couples: miR156/SBP, miR396/GRF and mir167/ARF8, suggesting not only that these miRNAs have the same activity also in peach, but also that miRNAs are deeply involved in the regulatory network underlying the peach fruit development. Appendix is a published study in which µPEACH3.0 is used to study the effects of wounding in two peach cultivars with different tolerance to this stress. RNA samples from wounded and unwounded mesocarps of melting cultivar Glohaven (GH) and slow melting cultivar BigTop (BT) were used. Transcriptomic data, confirmed by qRT-PCR analysis, showed the involvement of WRKY, AP2/ERF and HSP20 transcription factors in the GH response to wounding. Along with them, also genes involved in response to stresses, cell wall metabolism, phenilpropanoid and triterpenoid biosynthesis were found to be up regulated in the wounded GH mesocarp.Il pesco (Prunus persica) è uno dei più importanti alberi da frutto al mondo e la specie modello per le drupacee. Lo sviluppo del frutto di pesco è caratterizzato da un stretto rapporto tra il seme e il pericarpo durante i primi stadi, seguito negli stadi successivi da un disaccoppiamento nello schema di sviluppo dovuto alla lignificazione dell’endocarpo. Le varie cultivar di pesco possono avere dei periodi di sviluppo del frutto dalla lunghezza estremamente variabile, pur avendo un seme che si sviluppa in maniera simile. Per questo, comprendere la relazione tra seme e pericarpo può chiarire il meccanismo che regola lo sviluppo del frutto nel suo complesso. L’approccio transcrittomico è uno strumento potente per analizzare questa relazione, dato che produce un gran numero di informazioni sulla trascrizione di un gran quantitativo di geni in un singolo esperimento. Il Capitolo II consiste in un articolo pubblicato che descrive l’uso dell’array µPEACH1.0 nello studiare la relazione tra seme e mesocarpo e tra stadi iniziali e finali di sviluppo nella cultivar Fantasia. Campioni di mRNA di pesco sono stati raccolti dagli stadi iniziali e finali dei due organi e ibridizzati sulle 4 806 sonde dell’array µPEACH1.0. I dati trascrittomici ottenuti da questi campioni sono stati quindi confrontati. Sono stati trovati dei geni marcatori per i quattro stadi di sviluppo del pesco (Stadio S1: divisione ed espansione cellulare nel frutto, S2: lignificazione dell’endocarpo, S3: espansione cellulare nel mesocarpo, S4: maturazione) sia per il mesocarpo che per il seme e la loro espressione confermata con la qRT-PCR: I marcatori stadio-specifici per il mesocarpo sono rispettivamente per S1, S2, S3 e S4: una proteina RD22-like, una serin-carbossipeptidasi, una proteina correlata alla senescenza e una Aux/IAA; mentre per il seme sono, rispettivamente: una proteina trasportatrice di lipidi (LTP1), una proteina correlata alla patogenesi (PR), una prunina e una proteina LATE EMBRYOGENESIS ABUNDANT (LEA). La qRT-PCR ha confermato che questi geni sono marcatori anche in una cultivar precoce (SpringCrest) e in un genotipo a maturazione lenta (slr). Quindi i dati sono stati analizzati con lo strumento HORMONOMETER al fine di misurare indirettamente il quantitativo relativo di ormoni nei vari organi e stadi di sviluppo. E’ emerso che l’auxina, le citochinine e le gibberelline possono essere coinvolte nella segnalazione durante l’inizio dello sviluppo, quando vi è comunicazione tra i due organi. Il Capitolo III è un articolo non pubblicato nel quale viene descritto come venga utilizzata una nuova piattaforma microarray (µPEACH3.0) nello studiare lo sviluppo del seme e del mesocarpo di pesco. La recente pubblicazione del genoma di pesco ha permesso lo sviluppo di un microarray che copre l’intero genoma, superando così il problema di avere un array che misura l’espressione genica solo di una parte del genoma. Rispetto allo studio descritto nel Capitolo I, anche il numero di campioni è stato incrementato: sono state usate tre repliche biologiche per sei diversi momenti per ciascuno dei due organi, dando così una visuale più vasta sullo sviluppo di questi due tessuti. L’array µPEACH3.0 ha funzionato bene, dando una correlazione con i dati di qRT-PCR pari a 0.77, un numero simile a quello trovato per altri array. I dati trascrittomici hanno facilmente distinto i due tessuti e i sei campionamenti, come mostrato dall’analisi delle componenti principali. Il 69% delle sonde ha prodotto un segnale significativo in almeno uno dei campioni, ciò nonostante, considerando che il numero di sonde funzionanti decresce se si prende in considerazione un solo tessuto, è probabile che testando il microarray con mRNA proveniente da altri tessuti (come le foglie o le radici) aumenti il numero di segnali significativi provenienti dall’array. L’analisi globale dell’attività genica è stata indirizzata ai primi stadi di sviluppo. I dati hanno permesso di indentificare parecchi geni coinvolti nei processi del ciclo cellulare che si verificano all’inizio dello sviluppo sia del mesocarpo che del seme. In particolare, è stato trovate che geni della famiglia TITAN sono attivi nel seme contenente endosperma. L’analisi dei geni del ciclo cellulare nel mesocarpo ha mostrato l’esistenza di due diversi profili di espressione: mentre i geni relativi alla mitosi erano espressi solo nello stadio S1, i geni della replicazione del DNA hanno mostrato un doppio picco di espressione, in S1 e poi in S3/S4, suggerendo che in questi stadi possono verificarsi eventi di endoreduplicazione. Con l’utilizzo di qRT-PCR, i livelli d’esrpessione di questi geni sono stati testati anche in altre cultivar; i dati ottenuti suggeriscono che nel genotipo slr la mancanza di endoreduplicazione possa essere coinvolta nel basso tasso di crescita durante lo stadio S3 di questo genotipo. Sono stati quindi valutati i profili d’espressione di famiglie di fattori di trascrizione (FT), dato che si ritiene che i fattori di trascrizione siano le proteine con i ruoli più importanti nella regolazione durante lo sviluppo. E’ stato trovato che FT delle famiglia SQUAMOSA promoter Binding Protein (SBP) hanno un alto livello di espressione all’inizio dello sviluppo di entrambi gli organi considerati, il quale successivamente diminuisce velocemente. E’ stato scoperto che nel seme maturo è indotta la trascrizione di FT di tipo Growth-Regulating Factor (GRF). Questi dati sono stati confermati con l’utilizzo di qRT-PCR in ‘SpringCrest’ precoce e nel genotipo a lenta maturazione slr. Dato che in altre specie vegetali l’abbondanza dell’mRNA di geni appartenenti a queste famiglie di FT è regolata da microRNA (miRNA) specifici, è stata misurata l’espressione degli omologhi di pesco di questi miRNA. In tre diverse cultivar è stata trovata una correlazione negativa nel contenuto di RNA per le seguenti coppie microRNA/FT: miR156/SBP, miR396/GRF e mir167/ARF8, suggerendo non solo che questi miRNA posseggono la stessa attività un pesco, ma anche che i miRNA sono profondamente coinvolti nella rete regolativa sottostante lo sviluppo del frutto di pesco. In appendice vi è uno studio pubblicato nel quale viene descritto l’uso di µPEACH3.0 nello studiare gli effetti delle ferite su due cultivar con diversa tolleranza a questo stress. Sono stati utilizzati campioni di RNA estratti da mesocarpi feriti o intatti della cultivar “melting” Glohaven (GH) e della cultivar “slow melting” BigTop (BT). I dati trascrittomici, confermati dall’analisi tramite qRT-PCR, hanno mostrato il coinvolgimento di fattori di trascrizione di tipo WRKY, AP2/ERF, e HSP20 nella risposta di GH alla ferite. Insieme a questi, è stato trovato che nel mesocarpo ferito di GH viene indotta l’espressione anche di geni coinvolti nella risposta agli stress, nel metabolismo della parete cellulare, nella biosintesi dei fenilpropanoidi e triterpenoidi

Molecular and biochemical analyses of wounding in mesocarp of peach (Prunus persica L. Batsch) ripe fruits

The physiological and molecular responses of ripe fruit to wounding were evaluated in two peach (Prunus persica) varieties ('Glohaven', GH, melting and 'BigTop', BT, slow melting nectarine) by comparing mesocarp samples from wedges (as in minimal processing) and whole fruit as the control. Slight differences between the two varieties were detected in terms of ethylene production, whereas total phenol and flavonoid concentrations, and PPO and POD enzyme activities showed a general increase in wounded GH but not in BT. This was associated with the better appearance of the BT wedges at the end of the experimental period (72 h). Microarray (genome-wide mPEACH3.0) analysis revealed that a total number of 2218 genes were differentially expressed (p 1 or <-1) in GH 24 h after wounding compared to the control. This number was much lower (1208) in BT. According to the enrichment analysis, cell wall, plasma membrane, response to stress, secondary metabolic processes, oxygen binding were the GO categories over-represented among the GH up-regulated genes, whereas plasma membrane and response to endogenous stimulus were the categories over-represented among the down-regulated genes. Only 32 genes showed a common expression trend in the two varieties 24 h after wounding, whereas a total of 512 genes (with highly represented transcription factors), displayed opposite behavior. Quantitative RT-PCR analysis confirmed the microarray data for 18 out of a total of 20 genes selected. Specific WRKY, AP2/ERF and HSP20 genes were markedly up-regulated in wounded GH, indicating the activation of regulatory and signaling mechanisms probably related to different hormone categories. Compared to BT, the expression of specific genes involved in phenylpropanoid and triterpenoid biosynthetic pathways showed a more pronounced induction in GH, highlighting the difference between the two peach varieties in terms of molecular responses to wounding in the mesocarp tissue

A survey of geminiviruses and associated satellite DNAs in the cotton-growing areas of Northwestern India

Severe symptoms of cotton leaf curl disease (CLCuD) are caused by the association of a single-stranded circular DNA satellite (betasatellite) with a helper begomovirus. In this study, we analyzed 40 leaf samples (primarily cotton with CLCuD symptoms and other plants growing close by) from four sites between New Delhi and the Pakistan/India border, using rolling-circle amplification (RCA) and PCR. In total, the complete sequences of 12 different helper viruses, eight alphasatellites, and one betasatellite from five different plant species were obtained. A recombinant helper virus molecule found in okra and a novel alphasatellite-related DNA from croton are also described. This is the first report of the presence of both DNA components (helper virus and betasatellite) associated with resistance-breaking CLCuD in India, and it highlights the need for further work to combat its damage and spread

Molecular and biochemical responses to wounding in mesocarp of ripe peach (Prunus persica L. Batsch) fruit

tThe physiological and molecular responses of ripe fruit to wounding were evaluated in two peach (Prunuspersica) varieties (‘Glohaven’, GH, melting and ‘BigTop’, BT, slow melting nectarine) by comparing meso-carp samples from wedges (as in minimal processing) and whole fruit as the control. Slight differencesbetween the two varieties were detected in terms of ethylene production, whereas total phenol andflavonoid concentrations, and PPO and POD enzyme activities showed a general increase in wounded GHbut not in BT. This was associated with the better appearance of the BT wedges at the end of the exper-imental period (72 h). Microarray (genome-wide PEACH3.0) analysis revealed that a total number of2218 genes were differentially expressed (p 1 or <−1) in GH24 h after wounding compared to the control. This number was much lower (1208) in BT. According tothe enrichment analysis, cell wall, plasma membrane, response to stress, secondary metabolic processes,oxygen binding were the GO categories over-represented among the GH up-regulated genes, whereasplasma membrane and response to endogenous stimulus were the categories over-represented amongthe down-regulated genes. Only 32 genes showed a common expression trend in the two varieties 24 hafter wounding, whereas a total of 512 genes (with highly represented transcription factors), displayedopposite behavior. Quantitative RT-PCR analysis confirmed the microarray data for 18 out of a total of 20genes selected. Specific WRKY, AP2/ERF and HSP20 genes were markedly up-regulated in wounded GH,indicating the activation of regulatory and signaling mechanisms probably related to different hormonecategories. Compared to BT, the expression of specific genes involved in phenylpropanoid and triter-penoid biosynthetic pathways showed a more pronounced induction in GH, highlighting the differencebetween the two peach varieties in terms of molecular responses to wounding in the mesocarp tissu