Bud Activity Research Articles

Differential adaptation of high- and low-chill dormant peaches in winter through aquaporin gene expression and soluble sugar content

Plants have their own mechanisms for overcoming various stresses. In cold regions, plants are subject to stress and must enter an inherent dormancy, through several complex mechanisms, if they are to continue to exist. In winter, regulation of tonoplast and plasma membrane aquaporin genes differed in the bud cushions of the high-chill peach (Prunus persica L. Batsch) cv. Kansuke Hakuto and the low-chill peach cv. Coral. In December and January, when the temperature was lowest (around 2 degrees C), the increased expression of Pp-gammaTIP1 and Pp-PIP1 seen in the bud cushions of Kansuke Hakuto may have been related to the concomitant high-soluble sugar content of the cushions of this cultivar. This relationship may have made the cells highly stable and relatively unaffected by low-temperature stress owing to the presence of "glasses" that prevented ice nucleation. However, a simpler form of cold protection regulation seemed to occur in Coral, in which there was no winter increase in Pp-gammaTIP1 and Pp-PIP1 mRNA and a slow decline in total soluble sugar content in December and January. These results suggested that Pp-gammaTIP1 and Pp-PIP1, respectively, play important roles in intra- and intercellular membrane transport, enhancing cold resistance in the bud cushions of high-chill cultivars. In addition, Pp-deltaTIP1 and Pp-PIP2 mRNA increased at the end of endodormancy in both cultivars. This change may be induced by endodormancy-release signals and the resumption of bud activity in both cultivars.

The Z Protein of the New World Arenavirus Tacaribe Virus Has Bona Fide Budding Activity That Does Not Depend on Known Late Domain Motifs

The arenavirus small RING finger Z protein has been shown to be the main driving force of budding for several arenaviruses. This Z budding activity was found to be mediated by the late (L)-domain motifs P(T/S)AP and PPXY, located at the C terminus of Z. Here, we show that the Z protein of Tacaribe virus (TACV), a New World arenavirus, buds efficiently from cells despite lacking the canonical L-domain motifs P(T/S)AP and PPXY. Likewise, potential L-domain motifs ASAP and YLCL present in TACV Z did not exhibit any significant contribution to TACV Z budding activity. Budding of TACV Z was Tsg101 independent but required the activity of Vps4A/B. These results indicate that TACV Z utilizes a budding mechanism distinct from that reported for other arenaviruses.

Axillary bud outgrowth potential is determined by parent apical bud activity

Axillary buds within a plant shoot system are known to differ in their ability to respond to treatments favouring their development. This ability is referred to as their outgrowth potential. Using two species of prostrate nodally-rooting herbs, dicotyledonous Trifolium repens and monocotyledonous Tradescantia fluminensis, grown throughout in a strictly vegetative state, this study tested two hypotheses. Hypothesis 1: that each axillary bud exhibits an outgrowth potential that is directly related to the growth rate of its parent apical bud, and Hypothesis 2: that the growth rate attained by an axillary bud depends upon both its outgrowth potential and the local supply of stimulatory root-derived signal (NRS) available to it. Activation levels (growth rates) of apical buds were varied by differential exposure to nodal roots and the outgrowth responses of axillary buds recently emerged from them were then measured under standardized conditions of NRS supply. Hypothesis 1 was shown to be correct for both species. Hypothesis 2, tested only in T. repens, was supported by results showing that an axillary bud's outgrowth potential and the NRS supply to it each independently influenced its growth rate, there being no significant interaction between the two. These results emphasize the significant role the physiological state/activity of apical buds has on the outgrowth potential of axillary buds formed within them. The fact that similar relationships were observed on axillary buds on stems of differing developmental maturity and branching hierarchy, and in two taxonomically diverse species, suggests they might be widespread among morphologically similar species.

Overexpression of the Lily p70s6k Gene in Arabidopsis Affects Elongation of Flower Organs and Indicates TOR-Dependent Regulation of AP3, PI and SUP Translation

The p70 ribosomal S6 kinase (p70(s6k)) signaling pathway plays a key role in regulating the cell cycle via translational regulation of specific 5'TOP mRNAs. However, the function of this signaling pathway is still poorly understood in plants. Ectopic expression of the lily putative p70(s6k) gene, LS6K1, resulted in up-regulation of NAP (NAC-LIKE, ACTIVATED BY AP3/PI) and PISTILLATA (PI) expression, and significantly inhibited cell expansion for petals and stamens, resulting in the male sterility phenotype in transgenic Arabidopsis. Sequence analysis revealed that the genes involved in petal and stamen development, such as APETALA3 (AP3), PI and SUPERMAN (SUP), probably encode 5'TOP mRNAs. Green fluorescent protein (GFP), fused to oligopyrimidine tract sequences that were identified in the 5'-untranslated region (UTR) of AP3, PI and SUP, was translationally regulated in human cells in response to mitogen stimulation and inhibition by the macrolide antibiotic rapamycin. Furthermore, 35S::LS6K1 significantly up-regulated beta-glucuronidase (GUS) activity in the flower buds of transgenic plants carrying the GUS transgene fused to the AP3 promoter and the 5' UTR. These results have identified a novel role for the p70(s6k) gene in regulating cell division and the expansion of petals and stamens by translational regulation of the 5'TOP mRNAs once ectopically expressed in Arabidopsis.

Shoot branching control by reduced culm number 4 in rice ( Oryza sativa L.)

Shoot branching is a major factor in plant architecture and an important agronomic trait for productivity. In the present study, we characterized reduced culm number 4 (rcn4) mutants in rice, namely rcn4-1 and rcn4-2. rcn4 developed axillary buds precisely at each leaf node, but the outgrowth of these buds was inhibited. To determine whether rcn4 is involved in a branch-inhibiting strigolactone pathway, we characterized the double mutant of rcn4 and a tillering dwarf mutant, dwarf10 (d10), which is defective in strigolactone synthesis. The axillary bud activity of rcn4d10 double mutant was between that of the rcn4 and d10 mutants suggesting that Rcn4 controls axillary bud activity and is independent of D10 in the strigolactone associated branching inhibition pathway. Molecular mapping study demonstrated that Rcn4 is located between simple sequence repeat markers RM6581 and RM6608 on the long arm of rice chromosome 1. We suggest that Rcn4 is a good candidate for further investigation of the strigolactone independent branching pathway.

Tumor budding is predictive of lymphatic involvement and lymph node metastases in submucosal invasive colorectal adenocarcinomas and in non-polypoid compared with polypoid growths

Objective. Early colorectal carcinomas (submucosal invasive adenocarcinomas) can be classified into polypoid and non-polypoid growth types, the latter progressing more rapidly to advanced malignancy. The aim of this study was to investigate the differences between invasive features of the two types of carcinoma by focusing on tumor budding (isolated single cells or small cell clusters (up to four cells) scattered at invasive tumor margins). Material and methods. The number of foci in the field with the most frequent tumor budding was regarded as “activity”. Tumor budding was examined using anti-cytokeratin antibodies in 98 colorectal submucosal invasive adenocarcinomas and compared with the clinicopathological findings. In addition, the relationships between tumor budding and β-catenin and laminin-5γ2 expression were analyzed. Results. Tumor budding activity was significantly higher in non-polypoid growth carcinomas compared with polypoid growth carcinomas (p = 0.0006) and values for left-sided lesions were higher than those for right-sided lesions of the colon (p = 0.0108). Positive links with tumor budding were evident for lymphatic involvement and lymph node metastasis in non-polypoid growth carcinomas, and with laminin-5γ2 cytoplasmic expression in polypoid growth carcinomas. Multivariate logistic analysis revealed that the activity of tumor budding was an independent risk factor for lymphatic involvement. Conclusions. The results indicate that tumor budding makes a greater contribution to progression in non-polypoid than in polypoid growth carcinomas, with possible involvement of lymph node metastasis.

Metabolic activity of low chilling grapevine buds forced to break

This research documented the metabolic changes associated with the use of budbreak promoter sprays in vineyards. The objective was to evaluate metabolic heat production ( R q) and respiratory ( R C O 2 ) rates and water content of Vitis vinifera L. cv. ‘Flame Seedless’ buds during dormancy, and after spraying with the budbreak promoter, hydrogen cyanamide (H 2CN 2), assessing its effect on the developmental response of buds through several phenological phases in the vineyard. The study was conducted in the winter from November 24, 2005 to February 8, 2006 using isothermal calorimetry at 25 °C. Phenological stages monitored were dormant bud, swollen bud, half-inch green, first-flat leaf and second-flat leaf. On December 23, when 97 chilling units had accumulated, H 2CN 2 (0.82 M divided into two applications of 0.47 and 0.35 M) was applied and compared with untreated controls. Metabolic heat rates significantly ( p ≤ 0.05) increased from endodormant buds to the half-inch green stage, from 2 to 33 μW mg −1 dry weight (dw). This occurred from November 24 to January 15. Bud respiration rate showed a similar pattern, increasing from 3.7 to 346 nmoles CO 2 s −1 mg −1 dw, and bud water content increased from 2.2 to 5.6 mg mg −1 dw. In a 27-day period after spraying, treated vines reached 50% budbreak, while controls reached only 7%. Phenological development was heterogeneous due to insufficient chilling, as well as to low temperatures following H 2CN 2 application. Changes in R q and R C O 2 were detected 12 days in advance compared with changes in bud hydration.

Changes in aquaporin gene expression and magnetic resonance imaging of water status in peach tree flower buds during dormancy

The movement of cellular water accompanies changes in growth within dormant buds. To further understand this process, accumulation of tonoplast deltaTIP1 and plasma membrane PIP2 aquaporin transcripts was measured by quantitative reverse transcriptase-polymerase chain reaction and the water dynamics in dormant peach (Prunus persica L.) flower buds was studied by magnetic resonance imaging. Proton density (PD), spin-spin relaxation time (T(2)) and apparent diffusion coefficient (ADC) were used to observe water dynamics during dormancy. The expression of deltaTIP1 and PIP2 aquaporins, PD and T(2) in the upper part of the bud including primordia, in the basal part of the bud and the bud trace increased earlier in the low-chill cultivar 'Coral' than in the high-chill cultivar 'Kansuke Hakuto,' reflecting the difference in timing for the end of endodormancy in the two cultivars. deltaTIP1 mRNA accumulated mainly in the basal part of the bud, whereas PIP2 mRNA was detected mainly in the upper part. These findings may reflect the activation of inter- and intracell communication through membrane transport properties of aquaporins resulting in a gradual increase in water content to that required for bud activity at the end of endodormancy. An apparent decrease in the expression of deltaTIP1 and PIP2 mRNAs was, however, observed in late winter in some portions of the buds of both cultivars just before sprouting.

Expression of tea cytosolic glutamine synthetase is tissue specific and induced by cadmium and salt stress

Glutamine synthetase (GS) showed highest expression and activity in bud (youngest topmost leaf) of Camellia sinensis, lower in older leaves, while lowest activity in stem and roots. GS expression and activity was increased by ammonium and nitrate and also by cadmium and salt stress but decreased by copper, aluminum, drought, cold and heat stress.

H2O2 is involved in the dormancy-breaking effect of hydrogen cyanamide in grapevine buds

Hydrogen cyanamide (HC) is widely used to induce the breakage of endodormancy (ED) in grape and other deciduous fruit crop, though its mechanism of action is poorly understood. Applications of HC to grapevine buds produce oxidative stress and transient respiratory disturbances which are related to the breakage of ED. Moreover, since the expression and activity of catalase (Cat) is inhibited by HC, enhancements in the levels of H2O2 have also been associated to the breakage of ED in grapevine buds. Here, we reported that increases in H2O2 level in HC-treated grapevine buds are due to the inhibition of Cat activity and enhancement of the respiratory activity of buds. In addition, exogenous applications of H2O2 partially reproduced the inducing effect of HC in the breakage of ED, thus providing further support for the hypothesis that H2O2 mediates the effects of HC. On the other hand, Mit isolated from both control and HC-treated buds respired equally well when NADH was used as a respiratory substrate, but when succinate was used as an electron donor Mit respiration was non-detected, suggesting that the stimulatory effect of HC on bud respiration is related to metabolic alterations leading to increase of the concentration of NADH rather than to changes in Mit functionality.

Molecular Mechanism of Mitotic Golgi Disassembly and Reassembly Revealed by a Defined Reconstitution Assay

In mammalian cells, flat Golgi cisternae closely arrange together to form stacks. During mitosis, the stacked structure undergoes a continuous fragmentation process. The generated mitotic Golgi fragments are distributed into the daughter cells, where they are reassembled into new Golgi stacks. In this study, an in vitro assay has been developed using purified proteins and Golgi membranes to reconstitute the Golgi disassembly and reassembly processes. This technique provides a useful tool to delineate the mechanisms underlying the morphological change. There are two processes during Golgi disassembly: unstacking and vesiculation. Unstacking is mediated by two mitotic kinases, cdc2 and plk, which phosphorylate the Golgi stacking protein GRASP65 and thus disrupt the oligomer of this protein. Vesiculation is mediated by the COPI budding machinery ARF1 and the coatomer complex. When treated with a combination of purified kinases, ARF1 and coatomer, the Golgi membranes were completely fragmented into vesicles. After mitosis, there are also two processes in Golgi reassembly: formation of single cisternae by membrane fusion, and restacking. Cisternal membrane fusion requires two AAA ATPases, p97 and NSF (N-ethylmaleimide-sensitive fusion protein), each of which functions together with specific adaptor proteins. Restacking of the newly formed Golgi cisternae requires dephosphorylation of Golgi stacking proteins by the protein phosphatase PP2A. This systematic study revealed the minimal machinery that controls the mitotic Golgi disassembly and reassembly processes.

Frost induced changes in enzyme activities and carbohydrate content in the spurs of some pear cultivars during the dormancy

Frost tolerance of pear cultivars was checked after artificial cold treatment in 2003-2005. Limbs collected during the endodormancy were exposed in a climatic chamber for 24 hours to —25; —28 °C, while those collected in the ecodormancy were kept at —15 and —18 °C. Frost damages of buds were registered according to a visually defined scale, then peroxidase (POD), polyphenol oxidase (PPO) enzyme activities and carbohydrate contents were checked in buds and spur-part below the buds. POD activity of untreated control in tissue below buds was higher than in the buds, which were increasing continuously during the endodormancy and decreased at the end of the ecodormancy. During endodormancy, cold treatment of —25 and —28 °C effected different changes of enzyme activity in buds of the cultivars. In the ecodormancy, enzyme activities increased after a cold treatment of —15 °C, whereas the activities decreased significantly after —18 °C. `Kaiser' — susceptible to frost — with its higher values of both enzyme activities marked out from other cultivars, which is correlated with its stress response. Changes in carbohydrate components — especially in glucose — of buds monitored well the different stress responses of tolerant and resistant pear cultivars induced by frost stress.

Antidiabetic activity of flower buds of Michelia champaca Linn.

Objective:To identify the antihyperglycemic activity of various extracts, petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous and crude aqueous, of the flower buds of Michelia champaca, and to identify the antidiabetic activity of active antihyperglycemic extract.Materials and Methods:Plant extracts were tested for antihyperglycemic activity in glucose overloaded hyperglycemic rats. The effective antihyperglycemic extract was tested for its hypoglycemic activity at two-dose levels, 200 and 400 mg/kg respectively. To confirm its utility in the higher model, the effective extract of M. champaca was subjected to antidiabetic study in alloxan induced diabetic model at two dose levels, 200 and 400 mg/kg respectively. The biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein, hemoglobin and glycosylated hemoglobin were also assessed in the experimental animals.Results:The ethanolic extract of M. champaca exhibited significant antihyperglycemic activity but did not produce hypoglycemia in fasted normal rats. Apart from this extract, the crude aqueous and petroleum ether extracts were found active only at the end of the first hour. Treatment of diabetic rats with ethanolic extract of this plant restored the elevated biochemical parameters significantly (P<0.05) (P<0.01) and the activity was found dose dependent.Conclusion:This study supports the traditional claim and the ethanolic extract of this plant could be added in traditional preparations for the ailment of various diabetes-associated complications.

Genetic Consequences of Radiation Exposure for the Pine (Pinus sylvestris L.) Population.

We studied the inheritance of isoenzyme loci in seeds of the first post-accidental generation and morphological characteristics in the second generation of irradiated pines. Pine is an appropriate object for genetic monitoring due to its high radiosensitivity. In 2004 we collected seeds from the young pine trees (8-10 years) growing in the 30-km zone around the CNPP. These plants grew as a result of natural revival of population and presented second progeny of the irradiated trees. The absorbed doses in 1986 varied from 0.5 up to 40 Gy. Dose rates in 2004 varied from 0.25 up to 25 μZv/h. We assayed the isoenzyme polymorphism in endosperms using electroforetic analysis in polyacrilamid gel. The haploid endosperm presence allows to study genotype of maternal plant without crossing. The investigation revealed no mutational changes at isoenzyme loci. We observed inheritance of alleles of Gdh, Adh1, Adh2, Skdh1, Skdh2, Got2, Got loci and compared genotypes of heterozygous maternal plants with endospermes. The expected ratio of maternal alleles in haploid endosperm tissues is 1:1 in accordance with Mendelian inheritance. Significant deviation from 1:1 ratio was found at 6 of 7 loci of 50% observed heterozigous trees. The disturbances in the allelic segregation were not found in control. We found high level of morphological abnormalities in second post-accidental generation of pine. The frequency of chlorophyll mutations among two-years-old plants was 1.8%, the growing abnormalities (dwarfness, activation of rest buds)-6.7%, the cases of atavism (dichotomic stem-bifurcation, single sessile needles)-1.6%. Common frequency of morphological abnormalities is 10.1% (not found in control). The length of plants and needles was the same as in control. The quantity of morphological abnormalities didn’t depend on dose rate. Disturbances of allele segregation and high level of morphological abnormalities probably result in genetic injures in the second generation of the irradiated plants.

The Role of Sonic Hedgehog Signaling and Fibroblast Growth Factors in Tooth Development in Mice

Cell-based therapy combined with tissue stem cells and tissue-engineering technology is believed to be a very powerful tool for regeneration of the tooth root and periodontal tissue in the future. The molecular mechanism of tooth root development is useful for this therapy; however, not enough basic information has been accumulated about tooth root development. Reciprocal epithelial-mesenchymal interactions, polarized growth and complicated morphogenic events are involved in tooth development. Recently, a Sonic hedgehog (Shh)-fibroblast growth factor (Fgfs)-dependent regulatory mechanism was found in the developing tooth roots, in a previous report that dental tissues had zone polarizing activity (ZPA) in the chick limb bud. Shh-Fgfs morphogenetic signaling is conserved in the developing molar tooth roots, but a unique combination of Fgfs is used for molar tooth root development compared to the limb bud patterning process.

The Role of Sonic Hedgehog Signaling and Fibroblast Growth Factors in Tooth Development in Mice

Cell-based therapy combined with tissue stem cells and tissue-engineering technology is believed to be a very powerful tool for regeneration of the tooth root and periodontal tissue in the future. The molecular mechanism of tooth root development is useful for this therapy ; however, not enough basic information has been accumulated about tooth root development. Reciprocal epithelial-mesenchymal interactions, polarized growth and complicated morphogenic events are involved in tooth development. Recently, a Sonic hedgehog (Shh) -fibroblast growth factor (Fgfs) -dependent regulatory mechanism was found in the developing tooth roots, in a previous report that dental tissues had zone polarizing activity (ZPA) in the chick limb bud. Shh-Fgfs morphogenetic signaling is conserved in the developing molar tooth roots, but a unique combination of Fgfs is used for molar tooth root development compared to the limb bud patterning process.

Transcription factor AtDOF4;2 affects phenylpropanoid metabolism in Arabidopsis thaliana

In a phenotypic screen of plants constitutively overexpressing DOF (DNA-binding-with-one-finger) transcription factors under the control of the Cauliflower mosaic virus 35S promoter, AtDOF4;2 was identified as a gene inducing a bushy plant phenotype and potentially being involved in the regulation of phenylpropanoid metabolism in Arabidopsis. Further molecular and biochemical characterization was performed in parallel using transgenic plants with enhanced and reduced AtDOF4;2 expression. The expression pattern of AtDOF4;2 was determined by quantitative real-time polymerase chain reaction (Q-RTPCR) and through promoter-beta-glucuronidase (GUS) fusions, indicating preferential transcriptional activity in axillary buds of the flower stalk, the hypocotyls periderm and in tapetum cells. Constitutive overexpression and RNAi-mediated silencing of AtDOF4;2 caused reciprocal changes in the expression of flavonoid biosynthetic genes and the accumulation of flavonoids under cold and high-light conditions. Moreover, tapetum-specific overexpression of AtDOF4;2 led to pollen grains devoid of flavonols. In contrast to its negative influence on flavonoid biosynthesis and coincident with high expression in the periderm and tapetum, AtDOF4;2 positively influences the production of hydroxycinnamic acids in the hypocotyl and flower buds, implicating its possible importance for suberin and sporopollenin production. These data provide evidence that AtDOF4;2, influences phenylpropanoid metabolism in an environmental and tissue-specific manner.

Liver Fatty Acid-binding Protein Initiates Budding of Pre-chylomicron Transport Vesicles from Intestinal Endoplasmic Reticulum

The rate-limiting step in the transit of absorbed dietary fat across the enterocyte is the generation of the pre-chylomicron transport vesicle (PCTV) from the endoplasmic reticulum (ER). This vesicle does not require coatomer-II (COPII) proteins for budding from the ER membrane and contains vesicle-associated membrane protein 7, found in intestinal ER, which is a unique intracellular location for this SNARE protein. We wished to identify the protein(s) responsible for budding this vesicle from ER membranes in the absence of the requirement for COPII proteins. We chromatographed rat intestinal cytosol on Sephacryl S-100 and found that PCTV budding activity appeared in the low molecular weight fractions. Additional chromatographic steps produced a single major and several minor bands on SDS-PAGE. By tandem mass spectroscopy, the bands contained both liver and intestinal fatty acid-binding proteins (L- and I-FABP) as well as four other proteins. Recombinant proteins for each of the six proteins identified were tested for PCTV budding activity; only L-FABP and I-FABP (23% the activity of L-FABP) were active. The vesicles generated by L-FABP were sealed, contained apolipoproteins B48 and AIV, were of the same size as PCTV on Sepharose CL-6B, and by electron microscopy, excluded calnexin and calreticulin but did not fuse with cis-Golgi nor did L-FABP generate COPII-dependent vesicles. Gene-disrupted L-FABP mouse cytosol had 60% the activity of wild type mouse cytosol. We conclude that L-FABP can select cargo for and bud PCTV from intestinal ER membranes.

Cumulative activation of axillary buds by nodal roots in Trifolium repens L.

In Trifolium repens the rate of outgrowth of an axillary bud was closely correlated with its duration of exposure to a nearby nodal root. The dose-dependent nature of this relationship, over 0-22 d, is consistent with the concept that axillary buds are cumulatively activated by a root signal (RS) such that the longer they receive the signal the higher is their level of activation and hence their rate of outgrowth. Furthermore, the activation level attained by a bud was subsequently retained following the excision of the nodal root providing the source of its activation: its rate of growth 3-6 weeks after root excision still reflected the initial level of activation of the bud. Thus, once activated, a bud required relatively little RS to maintain its rate of outgrowth, implying that activation involves the establishment of an autonomous control mechanism within the bud itself. This provides an explanation of how a strongly activated apical bud can continue growth at relatively low RS levels when it is distanced from its nearest root system, while at the same time the prevailing low RS environment leads to weak activation of the axillary buds emerging from it.

Short day-photoperiod triggers and low temperatures increase expression of peroxidase RNA transcripts and basic peroxidase isoenzyme activity in grapevine buds

Expression of peroxidase (Prx) RNA transcripts was studied in grapevine cv. Thompson seedless through use of semi-quantitative RT-PCR. In roots, the three Vitis vinifera Prx ESTs, reported in the genomic facility database from the University of California ( http://cgf.ucdavis.edu), were expressed as RNA transcripts, and three Prx isoenzymes, two basic (PrxB1) and (PrxB2) and a neutral Prx isoenzyme (PrxN1), were detected in root extracts. In buds, although one Prx EST (CB923206) was detected as a RNA transcript, three Prx activities were found in its extract, these same being the two basic isoenzymes found in the roots, and an acidic one (PrxA1) as well. In field grown grapevines, Prx RNA transcript was expressed transiently during bud endodormancy (ED) while under controlled conditions in a growth chamber, a short day (SD) photoperiod triggered expression of the Prx transcript in bud cuttings; low temperature, enhanced its expression level. Because environmental cues that trigger and enhance Prx RNA transcript expression in bud-tissue are the same as those that induce bud-ED in Vitis, the transient expression of Prx EST (CB923206) identified in buds could signal the full extent of ED in grapevines.