Peach Bark Research Articles

Chemically-mediated colonization of black cherry by the peach bark beetle, Phloeotribus liminaris.

The peach bark beetle (Phloeotribus liminaris Harris, PBB) affects the health, quality, and value of black cherry (Prunus serotina Ehrh.) within the Central Hardwoods Forest Region of North America. When colonized by adult beetles, black cherry trees produce a defensive exudate, or 'gum', staining the wood and decreasing its value up to 90%. Current management tactics are inadequate to avoid extensive damage to most veneer-sized black cherry in the region. We test the hypothesis that PBB colonization behavior is chemically-mediated and determine the extent to which PBB is attracted to compounds associated with wounded or PBB-infested cherry wood. Through olfactometer and field bioassays, we determined that adult PBB were attracted to cherry branches infested with female beetles. We then used dynamic headspace sampling to collect volatiles associated with wounded and infested bolts of black cherry. The volatile benzaldehyde dominated these collections and was more abundant in aerations of female-infested bolts than other odor sources. In subsequent field bioassays, we evaluated the bioactivity of benzaldehyde, as well as α-longipinene, in combination with several chemical carriers. Traps baited with benzaldehyde captured more PBB than all other treatments, irrespective of other lure components. Moreover, PBB were not attracted to traps baited solely with ethanol, a common attractant for bark beetles that colonize hardwood trees. This is the first report of benzaldehyde as an attractant for a species of bark beetle and could aid in developing semiochemical-based management tactics for this important pest.

Differential gene expression in non-transgenic and transgenic \u201cM.26\u201d apple overexpressing a peach CBF gene during the transition from eco-dormancy to bud break

The CBF signal pathway is responsible for a significant portion of plant responses to low temperature and freezing. Overexpression of CBF genes in model organisms such as Arabidopsis thaliana enhances abiotic stress tolerance but also reduces growth. In addition to these effects, overexpression of the peach (Prunus persica [L.] Batsch) CBF1 gene in transgenic apple (Malus x domestica Borkh.) line T166 also results in early entry into and late exit from dormancy. Although the regulation of dormancy-induction and dormancy-release occur while the CBF regulon is operative in perennial, woody plants, how overexpression of CBF1 affects these dormancy-related changes in gene expression is incompletely understood. The objective of the present study was to characterize global changes in gene expression in peach CBF1-overexpressing and non-transformed apple bark tissues at different states of dormancy via RNA-seq. RNA-seq bioinformatics data was confirmed by RT-qPCR on a number of genes. Results indicate that the greatest number of significantly differentially expressed genes (DEGs) occurred in April when dormancy release and bud break normally occur but are delayed in Line T166. Genes involved in storage and inactivation of auxin, GA, and cytokinin were generally upregulated in T166 in April, while those for biosynthesis, uptake or signal transduction were generally downregulated in T166. Genes for cell division and cambial growth were also downregulated in T166 relative to the non-transformed line. These data suggest that overexpression of the peach CBF1 gene impacts growth hormone homeostasis and as a result the activation of growth in the spring, and most likely growth cessation in the fall as well.

Carbon to nitrogen ratio in peach bark and incidence of bacterial canker

Carbon to nitrogen ratio in peach bark and incidence of bacterial canker

STUDY OF NUTRITIONAL CONSTITUENTS AND SENSORY EVALUATION OF BAKERY PRODUCTS PREPARED FROM SEED AND BARK OF PRUNUS PERSICA (PEACH)

Medicinal plants are local heritage with global importance. Prunuspersica Seeds and Bark are used as traditional medicine for treatment of blood diseases, anemia rheumatism jaundice, antioxidant and anti-inflammatory agent. So the present study was planned for analysed the nutritional constituents of Prunuspersica Seeds and Bark such as Moisture, Protein, fat and ash were analyzed using AOAC methods. Carbohydrate content of the sample was estimated by Difference method. The research was designed to investigate proximate composition. The results of proximate analysis indicated that seeds and bark had appreciable amounts of Protein (2.2% and 1.0%), Carbohydrate (50.3% and 58.7%) and fat (36.9% and 29.2%) on dry basis with observed no significant difference (P≤0.05). Acceptability evaluation of prepared recopies was performed by semi trained panel through 9 point Hedonic rating scale test. The result revealed that among the recipes (Biscuits and Baked bite) prepared by adding 2%, 4%, 6% and 8% Powder of Seed and Bark that variant 1, 2 and 3 were acceptable when comparable to standard recipe. There is no significance difference (P≤0.005) when they were tested statistically. Considering the pharmaceutical action of Seeds and Bark for treatment of many diseases and that the reasonably safe to use, its development is important for the pharmaceutical industries. This study generated base line information about the peach Seeds and Bark which will be beneficial to treat various diseases. This study also indicates that both Seeds and Bark can be valuable in generating awareness among people to control various diseases and to improve their nutrition and health status.

Abundance and Distribution of Peach Bark Beetle in Northern Hardwood Stands of New York

Abundance and Distribution of Peach Bark Beetle in Northern Hardwood Stands of New York

Comparative expression and transcript initiation of three peach dehydrin genes

Dehydrin genes encode proteins with demonstrated cryoprotective and antifreeze activity, and they respond to a variety of abiotic stress conditions that have dehydration as a common component. Two dehydrins from peach (Prunus persica L. [Batsch.]) have been previously characterized; here, we describe the characterization of a third dehydrin from peach bark, PpDhn3, isolated by its response to low temperature. The expression of all three dehydrin genes was profiled by semi-quantitative reverse transcription PCR, and transcript initiation was mapped for all three genes using the RNA ligase-mediated 5' rapid amplification of cDNA ends technique. PpDhn3 transcripts from bark collected in December or July, as well as transcripts from developing fruit, initiated at a single site. Although most of the PpDhn1 transcripts initiated at a similar position, those from young fruit initiated much further upstream of the consensus TATA box. Bark and fruit transcripts encoding PpDhn2 initiated ca. 30 bases downstream of a consensus TATA box; however, transcripts from ripe fruit initiated further upstream. Ripe fruit transcripts of PpDhn2 contain a 5' leader intron which is predicted to add some 34 amino acids to the N-terminal methionine of the cognate protein when properly processed. Secondary structure prediction of sequences surrounding the TATA box suggests that conformational transitions associated with decreasing temperature contribute to the regulation of expression of the cold-responsive dehydrin genes. Taken together these results reveal new, unexpected levels of gene regulation contributing to the overall expression pattern of peach dehydrins.

Quantitative proteomic analysis of short photoperiod and low-temperature responses in bark tissues of peach (Prunus persica L. Batsch)

In the temperate climate of the northern hemisphere, winter survival of woody plants is determined by the ability to acclimate to freezing temperatures and to undergo a period of dormancy. Cold acclimation in many woody plants is initially induced by short photoperiod and low, non-freezing temperatures. These two factors (5°C and short photoperiod) were used to study changes in the proteome of bark tissues of 1-year-old peach trees. Difference in-gel electrophoresis technology, a gel-based approach involving the labeling of proteins with different fluorescent dyes, was used to conduct a quantitative assessment of changes in the peach bark proteome during cold acclimation. Using this approach, we were able to identify differentially expressed proteins and to assign them to a class of either ‘temperature-responsive’ or ‘photoperiod-responsive’ proteins. The most significant factor affecting the proteome appeared to be low temperature, while the combination of low temperature and short photoperiod was shown to act either synergistically or additively on the expression of some proteins. Fifty-seven protein spots on gels were identified by mass spectrometry. They included proteins involved in carbohydrate metabolism (e.g., enolase, malate dehydrogenase, etc), defense or protective mechanisms (e.g., dehydrin, HSPs, and PR-proteins), energy production and electron transport (e.g., adenosine triphosphate synthases and lyases), and cytoskeleton organization (e.g., tubulins and actins). The information derived from the analysis of the proteome is discussed as a function of the two treatment factors: low temperature and short photoperiod.

Global Analysis of Genes Regulated by Low Temperature and Photoperiod in Peach Bark

In response to environmental cues plants undergo changes in gene expression that result in the up- or down-regulation of specific genes. To identify genes in peach [Prunus persica (L.) Batsch.] trees whose transcript levels are specifically affected by low temperature (LT) or short day photoperiod (SD), we have created suppression subtractive hybridization (SSH) libraries from bark tissues sampled from trees kept at 5 °C and 25 °C under short day (SD) photoperiod or exposed to a night break (NB) interruption during the dark period of the SD cycle to simulate a long day (LD) photoperiod. Sequences expressed in forward and reverse subtractions using various subtracted combinations of temperature and photoperiod treatments were cloned, sequenced, and identified by BLAST and ClustalW analysis. Low temperature treatment resulted in the up-regulation of a number of cold-responsive and stress-related genes and suppression of genes involved in “housekeeping” functions (e.g., cell division and photosynthesis). Some stress-related genes not observed to be up-regulated under LT were increased in response to SD photoperiod treatments. Comparison of the patterns of expression as a consequence of different temperature and photoperiod treatments allowed us to determine the qualitative contribution of each treatment to the regulation of specific genes.

Characterization of Sequences Up-regulated in Peach Bark in Response to Low Temperature

Genes whose expression is regulated by exposure to low temperature (LT) in peach (Prunus persica L. Batsch.) bark were identified by PCR suppression subtractive hybridization. Among the genes identified by this technique were several that had previously been associated with LT responsiveness, as well as a few that have not been reported to be regulated by cold. Genes represented by the first group included Ppdhn1, previously characterized as a seasonally expressed gene predominantly seen in bark tissue collected in winter months. A novel dehydrin found in this study, Ppdhn3, was also observed to be up-regulated at LT and seasonally expressed. Two genes not previously associated with LT response were found to be up-regulated at 5 °C. These genes encode a polypeptide related to some unknown mitochondrial process (Pptar1p) or a transducin-like protein (Pptlp1) that may be associated with signal transduction. Expression of these genes with respect to seasonal variation and drought stress is compared to genes from peach bark (Ppdhn1 and Ppdhn2), whose patterns of expression in different seasons and under water deficit are well documented.

(455) Differential Patterns of Expression and Regulation of Two Dehydrin Genes from Peach (Prunus persica) Bark Tissues

We have characterized the seasonal accumulation of transcripts and proteins in peach (Prunuspersica), particularly a 60 kDa dehydrin (PCA60; PpDhn1). Recently, we have isolated another dehydrin gene (PpDhn2). The present report compares the structural organization of the two dehydrin genes, their promoters, and the response of the genes to temperature, photoperiod, and water deficit. Trees were exposed for 3 or 5 weeks to either short day (SD) or long day (LD) photoperiods at either 25 or 5 °C. Additional experiments exposed trees to a period of water deficit followed by recovery. Transcript abundance of both genes, as assessed by RT-PCR, was determined, in response to the different photoperiods and temperatures as well as a prolonged SD/5 °C regime, from monthly-collected field samples, and trees subjected to water deficit. Results indicated that water deficit increased transcript abundance of both genes, but their abundance differed dramatically in response to low temperature and seasonal cues. Surprisingly, neither gene exhibited a significant elevation in transcript abundance in response to SD conditions. The lack of response of PpDhn1to SD is problematical given the observation that transcript levels in field-collected samples begin to increase substantially in September, prior to the onset of cold temperatures. Analysis of the promoter regions and cis-acting elements suggest that ABA may play an important role in seasonal expression, interacting with photoperiod in field conditions. Two CRT/DRE elements are present in the promoter region of PpDhn1, but absent in the promoter of PpDhn2.

058 Cloning of a Defensin-related Gene and Its Expression during Dormancy and Fruit Development in Peach [Prunus persica (L.) Batsch

During the past several years we have been involved in identifying seasonally regulated proteins and genes from peach bark. In the present study, we describe the cloning of a protease inhibitor from a cDNA library made from winter bark tissues. A partial clone obtained from the library was extended to full length by 5' RACE. The full-length cDNA clone (final3b) is 613 bp in length, not including the poly A+ tail. The open reading frame of 237 bp codes for a 79 amino acid protease inhibitor related to the defensin family of proteins. This family of small, cysteine-rich, extracellular proteins play a role in the plantís defense response through their antifungal properties. Sequence comparison of the encoded protein using BLAST analysis revealed significant homology to protease inhibitors from Glycine max, Arabidopsis thaliana, and a defensin protein from bell pepper (Capsicum annuum). Similar to these other cysteine-rich proteins, the peach defensin contains a consensus cys arrangement and is predicted to have an amino terminal signal peptide, presumably targeting it for extracellular transport. RNA-blot analysis indicated that the gene is seasonally expressed in bark tissues of 1-year-old shoots. Transcript abundance of final3b increased in the fall, reached a peak in midwinter and then decreased. The gene was also expressed during early stages of fruit development. RNA-blot analysis of the gene in other tissues, and in response to environmental stress and wounding, is in progress.

Leucostoma persoonii . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Leucostoma persoonii . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Leucostoma persoonii is a widespread wound pathogen of fruit trees, especially of stone-fruit trees, being encountered mainly as the anamorph. It is a causal agent of mass wilting of branches and of dieback of young trees, commonly called ' Cytospora canker disease'. Infection sites may be in decaying fruit racemes and bark fissures due to excessive gum production following wounding or insect attack. The effect of fungicides on incidence of Leucostoma canker in stone-fruit trees was studied by Northover (1992). Biggs & Peterson (1990) investigated the effect of chemical applications to bark wounds on accumulation of lignin and suberin, and susceptibility of trees to Leucostoma persoonii . A virus-like particle of L. persoonii was isolated in pure culture and its characteristics were described (Jensen et al. , 1995). Comparative anatomy and host response of peach cultivars inoculated with L. persoonii was studied by Biggs (1986). An association between cultivar variation and temporal changes in the infection court after wounding of peach bark was demonstrated when twigs were infected by the fungus (Biggs, 1989). HOSTS: On dead or dying, attached or fallen twigs mainly of members of the Rosaceae ( Amelanchier, Armeniaca, Cerasus, Cotoneaster, Crataegus, Malus, Padus, Persica, Prunus, Pyrus, Rosa, Sorbus ), but also on Alnus . GEOGRAPHICAL DISTRIBUTION: Africa. Asia: Armenia, Cyprus, Republic of Georgia, Japan, Kazakhstan, Kirgizia, Russia, Turkmenia. Europe: Austria, Bulgaria, Czech Republic, Denmark, France, Germany, Greece, Ireland, Italy, Latvia, Poland, Rumania, Russia, Slovakia, Switzerland, Turkey, UK, Ukraine. North America: Canada (Alberta, Ontario), Mexico, USA (California, Colorado, Florida, Maryland, Michigan, New Jersey, West Virginia). South America: Brazil. TRANSMISSION: Both conidia and ascospores are air-borne, especially under humid conditions. In this case red or dark red droplets or tendrils of conidia are often exuded from the conidiomata. Viable spores are available throughout the year, with a summer maximum, and are affected by temperature and moisture. It is also known that arthropods can carry propagules in stone-fruit orchards (Helton et al. , 1988).

Influence of iron depletion on interactions between peach bark fungi in vitro

Iron requirements for growth, siderophore production and the interactions between predominant fungal epiphytes (Aureobasidium pullulans, Alternaria alternata, Epicoccum purpurascens, Coniothyrium olivaceum and Cladosporium herbarum) from peach bark were studied in vitro using different levels of iron availability at 15 and 26 C. Growth of these fungi on iron-limiting agar medium amended with the synthetic chelator, EDDHA was reduced. Production of siderophores by Au. pullulans, E. purpurascens and Co. olivaceum was determined by growth and color changes on Czapek's agar supplemented with chromazural-S. The greatest degree of antagonism was observed between pairings with E. purpurascens, Cl. herbarum and Co. olivaceum. Aureobasidium pullulans and Al. alternata were the least antagonistic fungi tested. Antagonistic interactions resulting in a deadlock occurred in 25% of interactions. Iron limitation resulted in a significant increase in antagonistic interactions between these fungi. There were no significant differences between the levels of antagonism at 15 C and 26 C.

Influence of Iron Depletion on Interactions between Peach Bark Fungi in Vitro

Influence of Iron Depletion on Interactions between Peach Bark Fungi in Vitro

An S-locus Receptor Protein Kinase from Peach is Expressed Predominantly in Fruit and Responds Differently to Various External Stresses

A receptor-like protein kinase (RLK) isolated from December peach bark (Ppsrlk1) was previously shown to have considerable homology to the S-locus class of RLKs associated with reproductive self-incompatibility. Unlike those RLKs, transcripts arising from Ppsrlk1 were not detectable in standard RNA blots. To determine the pattern of expression of this gene, RNAs from various peach tissues, some of which had been subjected to different stress treatments, were surveyed using Reverse Transcript-PCR (RT-PCR). Based on these results, select RNAs were further quantitated by Competitive PCR (C-PCR). RT-PCR of RNAs from seasonal peach bark revealed little change in the relative abundance of Ppsrlk1, although a slight decrease was noted in the RNAs from October and December bark. Expression of Ppsrlk1 in developing peach fruit peaked at stage II and declined thereafter from stage III and in the later stages of ripening. Ripe peach fruit subjected to 10 min UV treatment or wounding followed by application of a yeast biocontrol agent showed a further decline in Ppsrlk1 expression; C-PCR analysis of the wounded fruit indicated a five-fold difference in expression between wounded water controls and wounded fruit treated with the biocontrol agen 48 h after treatment. In bark and xylem tissues under water deficit conditions expression of Ppsrlk1 declined. In contrast, levels of Ppsrlk1 in leaves and roots increased. C-PCR of the root samples revealed a 50-fold increase in the transcript in response to water deficit.

Distribution of Seasonally Expressed Storage Proteins in Different-aged Shoots and Roots of `Loring' Peach

During autumnal leaf senescence, leaf nitrogen is translocated to other sites for storage, especially bark tissues. By definition, proteins that accumulate in large amounts in winter and are absent in summer are called storage proteins. Previously, we have characterized three proteins in peach bark tissues that fall into this category. Little is known, however, about the distribution of these proteins in different-aged tissues or whether they have any function other than to act as a nitrogen reserve. The present study characterizes the seasonal distribution of a 60-, 19-, and 16-kDa protein in bark tissues of current-year, 1-year-old, scaffold, and trunk bark, and 4- to 5-year-old roots of `Loring' peach. Verification of protein identity was based on molecular mass and reaction with antibodies directed against each specific protein. Distribution of the proteins was variable. The greatest amount of all three proteins was present in current-year and 1-year-old shoots. These tissues also showed the greatest seasonal variation in the amount of protein present. The 16-kDa protein was present only in the youngest shoots, whereas the 19-kDa was present in all tissues examined. The 60-kDa protein was absent in root tissue. The 60-kDa protein has been identified as a dehydrin, and the 16-kDa protein appears to be related to defensins. The identity of the 19-kDa protein has not been confirmed. The amino acid composition of the three proteins will be presented and the implications of these results on management practices will be discussed.

Mycoflora of peach bark: population dynamics and composition

Yeasts and filamentous fungi associated with smooth (non-lenticel) and lenticel bark of young and scaffold branches of peach (Prunus persica (L.) Batsch) were monitored using bark washing and direct or impression plating techniques and scanning electron microscopy during potential Cystospora canker infection periods. Total populations of fungi were high in the fall but dropped in the winter and increased during the spring. Yeasts and yeast-like fungi predominated in the spring and fall samples. The principal yeasts were Basidiomycetes in the form genera Cryptococcus, Rhodotorula, and Sporobolomyces. The yeast-like fungi were Aureobasidium and Taphrina. The principal filamentous fungi were in the form genera Alternaria, Epicoccum, Cladosporium, Coniothyrium, and Libertella. The canker pathogens, Leucostoma persoonii (Nits.) Höhn. and Leucostoma cincta (Pers. & Fr.) Höhn., were observed mainly in the spring sampling. Lenticels supported greater fungal populations than smooth (non-lenticel) bark surfaces. The impact of fungal epiphytes, particularly the yeasts, on the potential biological control of peach canker is discussed.Key words: Cytospora canker, mycoflora, yeast, bark, biological control, fungal epiphyte.

Mycoflora of peach bark: population dynamics and composition

Mycoflora of peach bark: population dynamics and composition

Immunolocalization and in Vitro Cryoprotective Activity of PCA60: A Peach Dehydrin

Cold acclimation in temperate, woody plants is a complex phenomenon that involves distinct changes in gene activity and protein synthesis. In previous research, a 60-kDa protein (PCA60), belonging to the dehydrin family of stress-related proteins, was identified in peach bark, and its corresponding gene (ppdhn1) was cloned and characterized. Presently, we report on the results of immunolocalization studies and in vitro cryoprotection assays. Seasonal collections of current-year stems were embedded in LR White or epoxy resin and sections of bark were probed with either a polyclonal antibody directed against a 15 amino acid sequence consensus region of dehydrins or a polyclonal antibody directed against partially-purified PCA60. In vitro cryoprotection assays utilized lactose dehydrogenase (LDH), a cold-labile enzyme. Immunolocalization at the light level indicated that the dehydrin was confined to the cytoplasm and absent in organelles. This localization was preliminarily confirmed at the ultrastructural level. LDH assays indicated cryoprotective activity in total protein extracts collected from winter bark tissues but completely absent in extracts of summer bark tissues. Preliminary LDH assays utilizing purified PCA60 also demonstrated cryoprotective activity. In general, the data further support a role for dehydrins in cold acclimation of woody plants.

Cold Acclimation and Alterations in Dehydrin-like and Bark Storage Proteins in the Leaves of Sibling Deciduous and Evergreen Peach

Seasonal changes in cold tolerance and proteins were studied in the leaves of sibling deciduous and evergreen peach [Prunus persica (L.) Batsch]. Freezing tolerance [defined as the subzero temperature at which 50% injury occurred (LT50)] was assessed using electrolyte leakage. Proteins were separated by sodium dodecyl sulfate polyacrylamide-gel electrophoresis. Electroblots were probed with anti-dehydrin and anti-19-kD peach bark storage protein (BSP) antibodies. Leaf LT50 decreased successively from -5.8 °C on 18 Aug. to -10.3 °C in the evergreen genotype and from -7.0 °C to -15.0 °C in the deciduous genotype by 14 Oct. Protein profiles and immunoblots indicated the accumulation of a 60- and 30-kD protein during cold acclimation in the leaves of deciduous trees; however, levels of these proteins did not change significantly in the evergreen trees. Immunoblots indicate that the 60-kD protein is a dehydrin-like protein. Gel-electrophoresis and immunoblots also indicated that the 19-kD BSP progressively disappeared from summer through fall in leaves of deciduous peach but accumulated to a high level in bark tissues. A similar inverse relationship was not evident in evergreen peach.