Association of asthma risk factors and the prevalence of the disease in a population of Brazil.

Summary: The objective of our study was to evaluate the association between the previously described asthma risk factors and the prevalence of asthma in a population of Brazilian adults. A population-based cross-sectional study was conducted using data collected from 7891 patients. All patients in the database > 18 years of age were included. The following variables were collected from the health plan database: age, body mass index, smoking status, alcohol consumption, sedentary lifestyle, heart disease, hypertension, diabetes, and asthma diagnosis. The frequency of the collected variables was compared between patients with or without an asthma diagnosis, and logistic regression was performed. Of our total sample (7891 patients), 150 (1.9%) had asthma. The mean age of patients with asthma was 39.4 years. 1.4% of normal weight patients had the diagnosis of asthma, while 2.4% of overweight and 2.2% of obese patients had the diagnosis. Multivariate analysis demonstrated that a sedentary lifestyle and overweight and obesity were independently associated with asthma prevalence Odds Ratio (OR) (95% confidence interval): (1.61 (1.16-2.22) and 1.25 (1.03-1.52) respectively). Our data provide evidence that some clinical characteristics, such as sedentarism, overweight, and obesity, may be related to the prevalence of asthma in an adult population in southeastern Brazil. Such factors could be modified and better understood through multidisciplinary research and health programs that evaluate the risk factors for asthma in large populations.

Comparative Proteomic Analysis of Nodulated and Non-Nodulated Casuarina glauca Sieb. ex Spreng. Grown under Salinity Conditions Using Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS).

Casuarina glauca displays high levels of salt tolerance, but very little is known about how this tree adapts to saline conditions. To understand the molecular basis of C. glauca response to salt stress, we have analyzed the proteome from branchlets of plants nodulated by nitrogen-fixing Frankia Thr bacteria (NOD+) and non-nodulated plants supplied with KNO3 (KNO3+), exposed to 0, 200, 400, and 600 mM NaCl. Proteins were identified by Short Gel, Long Gradient Liquid Chromatography coupled to Tandem Mass Spectrometry and quantified by Sequential Window Acquisition of All Theoretical Mass Spectra -Mass Spectrometry. 600 proteins were identified and 357 quantified. Differentially Expressed Proteins (DEPs) were multifunctional and mainly involved in Carbohydrate Metabolism, Cellular Processes, and Environmental Information Processing. The number of DEPs increased gradually with stress severity: (i) from 7 (200 mM NaCl) to 40 (600 mM NaCl) in KNO3+; and (ii) from 6 (200 mM NaCl) to 23 (600 mM NaCl) in NOD+. Protein-protein interaction analysis identified different interacting proteins involved in general metabolic pathways as well as in the biosynthesis of secondary metabolites with different response networks related to salt stress. Salt tolerance in C. glauca is related to a moderate impact on the photosynthetic machinery (one of the first and most important stress targets) as well as to an enhancement of the antioxidant status that maintains cellular homeostasis.

Repercussions of melatonin on the risk of breast cancer: a systematic review and meta-analysis.

Breast Cancer is common in women, but its etiology is not yet fully understood. Several factors may contribute to its genesis, such as genetics, lifestyle, and the environment. Melatonin may be involved in the process of breast cancer. Therefore, the aim of this study is to evaluate the influence of the levels of melatonin on breast cancer through a systematic review and meta-analysis. We performed a systematic review according to PRISMA recommendations. The primary databases MEDLINE, Embase, and Cochrane were consulted. There was no restriction on the year of publication and language. Data of systematic reviews from April 2017 to September to 2017 were analyzed. The meta-analysis was conducted using RevMan 5.3 software provided by the Cochrane Collaboration. From a total of 570 articles, 9 manuscripts were included in this review. They analy onzed women with breast cancer and control patients, of which 10% and 90% were in the reproductive period and after menopause, respectively. The lowest level of melatonin was found in approximately 55% of studies with breast cancer in post-menopause. The metanalyses of the studies demonstrated low levels of melatonin in breast cancer patients (n=963) compared with control patients (n= 1332), with a mean difference between the studies of -3.54 (CI -6.01, -1.06). Another difference found was in the comparison between smoking patients, with an average difference between 1.80 [0.97-2.63]. Our data suggest that low levels of melatonin might be a risk factor for breast cancer.

Repercussions of melatonin on the risk of breast cancer: a systematic review and meta-analysis

SUMMARY Breast Cancer is common in women, but its etiology is not yet fully understood. Several factors may contribute to its genesis, such as genetics, lifestyle, and the environment. Melatonin may be involved in the process of breast cancer. Therefore, the aim of this study is to evaluate the influence of the levels of melatonin on breast cancer through a systematic review and meta-analysis. We performed a systematic review according to PRISMA recommendations. The primary databases MEDLINE, Embase, and Cochrane were consulted. There was no restriction on the year of publication and language. Data of systematic reviews from April 2017 to September to 2017 were analyzed. The meta-analysis was conducted using RevMan 5.3 software provided by the Cochrane Collaboration. From a total of 570 articles, 9 manuscripts were included in this review. They analy onzed women with breast cancer and control patients, of which 10% and 90% were in the reproductive period and after menopause, respectively. The lowest level of melatonin was found in approximately 55% of studies with breast cancer in post-menopause. The metanalyses of the studies demonstrated low levels of melatonin in breast cancer patients (n=963) compared with control patients (n= 1332), with a mean difference between the studies of 8722;3.54 (CI8722;6.01,8722;1.06). Another difference found was in the comparison between smoking patients, with an average difference between 1.80 [0.97-2.63]. Our data suggest that low levels of melatonin might be a risk factor for breast cancer.

RESUMO O câncer de mama é comum em mulheres, mas sua etiologia ainda não é totalmente compreendida. Vários fatores podem contribuir para sua gênese, genética, estilo de vida e meio ambiente. A melatonina pode estar envolvida no processo de câncer de mama. Portanto, o objetivo deste estudo é avaliar a influência dos níveis de melatonina no câncer de mama por meio de uma revisão sistemática e meta-análise. Realizamos uma revisão sistemática de acordo com as recomendações do Prisma. Os principais bancos de dados, Medline, Embase e Cochrane, foram consultados. Não houve restrição quanto ao ano de publicação e idioma. Os dados de revisão sistemática obtidos de abril de 2017 a setembro a 2017 foram analisados. A meta-análise foi conduzida pelo programa RevMan 5.3 fornecido pela Cochrane Collaboration. De um total de 570 artigos, nove foram incluídos nesta revisão. As análises foram conduzidas em mulheres com câncer de mama e pacientes controle, dos quais 10% e 90% estavam no período reprodutivo e após a menopausa, respectivamente. O nível mais baixo de melatonina foi encontrado em aproximadamente 55% dos estudos com câncer de mama na pós-menopausa. As meta-análises de estudos demonstraram os baixos níveis de melatonina em doentes com câncer da mama (n=963), em comparação com os pacientes de controle (n=1.332), sendo a diferença de médias entre os estudos da 8722;3,54 (CI 8722;6,01, 8722;1,06). Outra diferença é demonstrada nas comparações entre pacientes fumantes, sendo a diferença da média entre 1,80 [0,97-2,63]. Nossos dados sugerem que baixos níveis de melatonina podem ser um fator de risco para câncer de mama.

The draft genome sequence of cork oak.

Cork oak (Quercus suber) is native to southwest Europe and northwest Africa where it plays a crucial environmental and economical role. To tackle the cork oak production and industrial challenges, advanced research is imperative but dependent on the availability of a sequenced genome. To address this, we produced the first draft version of the cork oak genome. We followed a de novo assembly strategy based on high-throughput sequence data, which generated a draft genome comprising 23,347 scaffolds and 953.3 Mb in size. A total of 79,752 genes and 83,814 transcripts were predicted, including 33,658 high-confidence genes. An InterPro signature assignment was detected for 69,218 transcripts, which represented 82.6% of the total. Validation studies demonstrated the genome assembly and annotation completeness and highlighted the usefulness of the draft genome for read mapping of high-throughput sequence data generated using different protocols. All data generated is available through the public databases where it was deposited, being therefore ready to use by the academic and industry communities working on cork oak and/or related species.

Genetic Diversity and Physiological Performance of Portuguese Wild Beet (Beta vulgaris spp. maritima) from Three Contrasting Habitats.

The establishment of stress resilient sugar beets (Beta vulgaris spp. vulgaris) is an important breeding goal since this cash crop is susceptible to drought and salinity. The genetic diversity in cultivated sugar beets is low and the beet wild relatives are useful genetic resources for tolerance traits. Three wild beet populations (Beta vulgaris spp. maritima) from contrasting environments, Vaiamonte (VMT, dry inland hill), Comporta (CMP, marsh) and Oeiras (OEI, coastland), and one commercial sugar beet (Isella variety, SB), are compared. At the genetic level, the use of six microsatellite allowed to detect a total of seventy six alleles. It was observed that CMP population has the highest value concerning the effective number of alleles and of expected heterozygosity. By contrast, sugar beet has the lowest values for all the parameters considered. Loci analysis with STRUCTURE allows defining three genetic clusters, the sea beet (OEI and CMP), the inland ruderal beet (VMT) and the sugar beet (SB). A screening test for progressive drought and salinity effects demonstrated that: all populations were able to recover from severe stress; drought impact was higher than that from salinity; the impact on biomass (total, shoot, root) was population specific. The distinct strategies were also visible at physiological level. We evaluated the physiological responses of the populations under drought and salt stress, namely at initial stress stages, late stress stages, and early stress recovery. Multivariate analysis showed that the physiological performance can be used to discriminate between genotypes, with a strong contribution of leaf temperature and leaf osmotic adjustment. However, the separation achieved and the groups formed are dependent on the stress type, stress intensity and duration. Each of the wild beet populations evaluated is very rich in genetic terms (allelic richness) and exhibited physiological plasticity, i.e., the capacity to physiologically adjust to changing environments. These characteristics emphasize the importance of the wild beet ecotypes for beet improvement programs. Two striking ecotypes are VMT, which is the best to cope with drought and salinity, and CMP which has the highest root to shoot ratio. These genotypes can supply breeding programs with distinct goals.

Protein Dynamics in the Plant Extracellular Space.

The extracellular space (ECS or apoplast) is the plant cell compartment external to the plasma membrane, which includes the cell walls, the intercellular space and the apoplastic fluid (APF). The present review is focused on APF proteomics papers and intends to draw information on the metabolic processes occurring in the ECS under abiotic and biotic stresses, as well as under non-challenged conditions. The large majority of the proteins detected are involved in "cell wall organization and biogenesis", "response to stimulus" and "protein metabolism". It becomes apparent that some proteins are always detected, irrespective of the experimental conditions, although with different relative contribution. This fact suggests that non-challenged plants have intrinsic constitutive metabolic processes of stress/defense in the ECS. In addition to the multiple functions ascribed to the ECS proteins, should be considered the interactions established between themselves and with the plasma membrane and its components. These interactions are crucial in connecting exterior and interior of the cell, and even simple protein actions in the ECS can have profound effects on plant performance. The proteins of the ECS are permanently contributing to the high dynamic nature of this plant compartment, which seems fundamental to plant development and adaptation to the environmental conditions.

Proteomic analysis of apoplastic fluid of Coffea arabica leaves highlights novel biomarkers for resistance against Hemileia vastatrix.

A proteomic analysis of the apoplastic fluid (APF) of coffee leaves was conducted to investigate the cellular processes associated with incompatible (resistant) and compatible (susceptible) Coffea arabica-Hemileia vastatrix interactions, during the 24-96 hai period. The APF proteins were extracted by leaf vacuum infiltration and protein profiles were obtained by 2-DE. The comparative analysis of the gels revealed 210 polypeptide spots whose volume changed in abundance between samples (control, resistant and susceptible) during the 24-96 hai period. The proteins identified were involved mainly in protein degradation, cell wall metabolism and stress/defense responses, most of them being hydrolases (around 70%), particularly sugar hydrolases and peptidases/proteases. The changes in the APF proteome along the infection process revealed two distinct phases of defense responses, an initial/basal one (24-48 hai) and a late/specific one (72-96 hai). Compared to susceptibility, resistance was associated with a higher number of proteins, which was more evident in the late/specific phase. Proteins involved in the resistance response were mainly, glycohydrolases of the cell wall, serine proteases and pathogen related-like proteins (PR-proteins), suggesting that some of these proteins could be putative candidates for resistant markers of coffee to H. vastatrix. Antibodies were produced against chitinase, pectin methylesterase, serine carboxypeptidase, reticuline oxidase and subtilase and by an immunodetection assay it was observed an increase of these proteins in the resistant sample. With this methodology we have identified proteins that are candidate markers of resistance and that will be useful in coffee breeding programs to assist in the selection of cultivars with resistance to H. vastatrix.

Effect of greenhouse conditions on the leaf apoplastic proteome of Coffea arabica plants.

This work describes the coffee leaf apoplastic proteome and its modulation by the greenhouse conditions. The apoplastic fluid (APF) was obtained by leaf vacuum infiltration, and the recovered proteins were separated by 2-DE and subsequently identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry, followed by homology search in EST coffee databases. Prediction tools revealed that the majority of the 195 identified proteins are involved in cell wall metabolism and in stress/defense responses. Although most of the proteins follow the classical secretory mechanism, a low percentage of them seem to result from unconventional secretion (leaderless secreted proteins). Principal components analysis revealed that the APF samples formed two distinct groups, with the temperature amplitude mostly contributing for this separation (higher or lower than 10°C, respectively). Sixty one polypeptide spots allowed defining these two groups and 28 proteins were identified, belonging to carbohydrate metabolism, cell wall modification and proteolysis. Interestingly stress/defense proteins appeared as more abundant in Group I which is associated with a higher temperature amplitude. It seems that the proteins in the coffee leaf APF might be implicated in structural modifications in the extracellular space that are crucial for plant development/adaptation to the conditions of the prevailing environment. BIOLOGICAL SIGNIFICANCE: This is the first detailed proteomic study of the coffee leaf apoplastic fluid (APF) and of its modulation by the greenhouse conditions. The comprehensive overview of the most abundant proteins present in the extra-cellular compartment is particularly important for the understanding of coffee responses to abiotic/biotic stress. This article is part of a Special Issue entitled: Environmental and structural proteomics.

Two traditional maize inbred lines of contrasting technological abilities are discriminated by the seed flour proteome.

The seed proteome of two traditional maize inbred lines (pb269 and pb369) contrasting in grain hardness and in preferable use for bread-making was evaluated. The pb269 seeds, of flint type (i.e., hard endosperm), are preferably used by manufacturers, while pb369 (dent, soft endosperm) is rejected. The hypothesis that the content and relative amounts of specific proteins in the maize flour are relevant for such discrimination of the inbred lines was tested. The flour proteins were sequentially extracted following the Osborne fractionation (selective solubilization), and the four Osborne fractions were submitted to two-dimensional electrophoresis (2DE). The total amount of protein extracted from the seeds was not significantly different, but pb369 flour exhibited significantly higher proportions of salt-extracted proteins (globulins) and ethanol-extracted proteins (alcohol-soluble prolamins). The proteome analysis allowed discrimination between the two inbred lines, with pb269 demonstrating higher heterogeneity than pb369. From the 967 spots (358 common to both lines, 208 specific to pb269, and 401 specific to pb369), 588 were submitted to mass spectrometry (MS). Through the combined use of trypsin and chymotrypsin it was possible to identify proteins in 436 spots. The functional categorization in combination with multivariate analysis highlighted the most discriminant biological processes (carbohydrate metabolic process, response to stress, chitin catabolic process, oxidation-reduction process) and molecular function (nutrient reservoir activity). The inbred lines exhibited quantitative and qualitative differences in these categories. Differences were also revealed in the amounts, proportions, and distribution of several groups of storage proteins, which can have an impact on the organization of the protein body and endosperm hardness. For some proteins (granule-bound starch synthase-1, cyclophilin, zeamatin), a change in the protein solubility rather than in the total amount extracted was observed, which reveals distinct in vivo associations and/or changes in binding strength between the inbred lines. Our approach produced information that relates protein content, relative protein content, and specific protein types to endosperm hardness and to the preferable use for "broa" bread-making.

Reference gene selection for quantitative real-time PCR normalization in Quercus suber.

The use of reverse transcription quantitative PCR technology to assess gene expression levels requires an accurate normalization of data in order to avoid misinterpretation of experimental results and erroneous analyses. Despite being the focus of several transcriptomics projects, oaks, and particularly cork oak (Quercus suber), have not been investigated regarding the identification of reference genes suitable for the normalization of real-time quantitative PCR data. In this study, ten candidate reference genes (Act, CACs, EF-1α, GAPDH, His3, PsaH, Sand, PP2A, ß-Tub and Ubq) were evaluated to determine the most stable internal reference for quantitative PCR normalization in cork oak. The transcript abundance of these genes was analysed in several tissues of cork oak, including leaves, reproduction cork, and periderm from branches at different developmental stages (1-, 2-, and 3-year old) or collected in different dates (active growth period versus dormancy). The three statistical methods (geNorm, NormFinder, and CV method) used in the evaluation of the most suitable combination of reference genes identified Act and CACs as the most stable candidates when all the samples were analysed together, while ß-Tub and PsaH showed the lowest expression stability. However, when different tissues, developmental stages, and collection dates were analysed separately, the reference genes exhibited some variation in their expression levels. In this study, and for the first time, we have identified and validated reference genes in cork oak that can be used for quantification of target gene expression in different tissues and experimental conditions and will be useful as a starting point for gene expression studies in other oaks.

Spiritist psychiatric hospitals in Brazil: integration of conventional psychiatric treatment and spiritual complementary therapy.

In Brazil, during the XX century, dozens of Spiritist psychiatric hospitals emerged seeking to integrate conventional medical treatment with complementary spiritual therapy. This combined inpatient treatment is largely found in Brazil, where many psychiatric hospitals stem from the Spiritist movement. The present report describes the use of these spiritual practices, their operating structure, health professionals involved, modalities of care, and institutional difficulties in integrating spiritual practices with conventional treatment in six leading Brazilian Spiritist psychiatric hospitals. These hospitals combine conventional psychiatric treatment with voluntary-based spiritual approaches such as laying on of hands ("fluidotherapy"), lectures regarding spiritual and ethical issues, intercessory prayer, spirit release therapy ("disobsession") and "fraternal dialogue". The non-indoctrination and optional nature of these spiritual complementary therapies seem to increase acceptance among patients and their family members. In conclusion, the Spiritist psychiatric hospitals in Brazil have, for more than half a century, provided an integrative approach in the treatment of psychiatric disorders, associating conventional and spiritual treatments, more specifically Spiritist therapy. The lack of standardized treatment protocols and scientific studies remain a barrier to assessing the impact of this integrative approach on patients' mental health, quality of life, adherence, and perceived quality of treatment.

Temperature stress effects in Quercus suber leaf metabolism.

Based on projections that climate changes are will intensify in the near future, it is important to understand how plants respond to climate. Consequently, we have been studying the effect of contrasting temperatures on leaf metabolism of Quercus suber, an important Mediterranean oak. Potted plants were grown under controlled conditions for 53 days at 28°C or 10°C. The accumulation of major soluble metabolites was analyzed by NMR. The relative levels of transcripts of genes encoding key enzymes of the shikimate and phenylpropanoid pathway (CS, PAL, CAD and ChS) were examined by means of quantitative, real-time RT-PCR. At 10°C, in the pre-existing leaves, the concentrations of sucrose, quercitol and catechin were higher, as were PAL and ChS transcripts. At 28°C, however, it was the concentration of quinic acid that was higher, as were the concentrations of CS and CAD transcripts. We conclude that contrasting temperatures greatly influence Q. suber metabolism and that a deeper analysis of the effects of more extreme temperatures is needed to understand the possible effects of temperature changes on Q. suber metabolism and physiology.

Proteins associated with cork formation in Quercus suber L. stem tissues.

Cork (phellem) formation in Quercus suber stem was studied by proteomic analysis of young shoots of increasing age (Y0, Y1 and Y4) and recently-formed phellem (Y8Ph) and xylem (Y8X) from an 8-year-old branch. In this study 99 proteins were identified, 45 excised from Y8X and 54 from Y8Ph. These ones, specifically associated with phellem, are of "carbohydrate metabolism" (28%), "defence" (22%), "protein folding, stability and degradation" (19%), "regulation/signalling" (11%), "secondary metabolism" (9%), "energy metabolism" (6%), and "membrane transport" (2%). The identification in phellem of galactosidases, xylosidases, apiose/xylose synthase, laccases and diphenol oxidases suggests intense cell wall reorganization, possibly with participation of hemicellulose/pectin biosynthesis and phenol oxidation. The identification of proteasome subunits, heat shock proteins, cyclophylin, subtilisin-like proteases, 14-3-3 proteins, Rab2 protein and enzymes interacting with nucleosides/nucleic acids gives additional evidence for cellular reorganization, involving cellular secretion, protein turnover regulation and active control processes. The high involvement in phellem of defence proteins (thioredoxin-dependent peroxidase, glutathione-S-transferase, SGT1 protein, cystatin, and chitinases) suggests a strong need for cell protection from the intense stressful events occurring in active phellem, namely, desiccation, pests/disease protection, detoxification and cell death. Identically, highly enhanced defence functions were previously reported for potato periderm formation.

Proteomic evaluation of wound-healing processes in potato (Solanum tuberosum L.) tuber tissue.

Proteins from potato (Solanum tuberosum L.) tuber slices, related to the wound-healing process, were separated by 2-DE and identified by an MS analysis in MS and MS/MS mode. Slicing triggered differentiation processes that lead to changes in metabolism, activation of defence and cell-wall reinforcement. Proteins related to storage, cell growth and division, cell structure, signal transduction, energy production, disease/defence mechanisms and secondary metabolism were detected. Image analysis of the 2-DE gels revealed a time-dependent change in the complexity of the polypeptide patterns. By microscopic observation the polyalyphatic domain of suberin was clearly visible by D4, indicating that a closing layer (primary suberisation) was formed by then. A PCA of the six sampling dates revealed two time phases, D0-D2 and D4-D8, with a border position between D2 and D4. Moreover, a PCA of differentially expressed proteins indicated the existence of a succession of proteomic events leading to wound-periderm reconstruction. Some late-expressed proteins (D6-D8), including a suberisation-associated anionic peroxidase, have also been identified in the native periderm. Despite this, protein patterns of D8 slices and native periderm were still different, suggesting that the processes of wound-periderm formation are extended in time and not fully equivalent. The information presented in this study gives clues for further work on wound healing-periderm formation processes.

Discovery of novel plant peptides as strong inhibitors of metalloproteinases.

Five novel metalloproteinase protein inhibitors (MPIs) with molecular mass between 5.6 and 8.9 kDa and acid/neutral pI were detected in lupin seeds and exhibited strong inhibitory activities against thermolysin and/or gelatinase B. These novel peptides constitute not only the first MPIs described in plants but also the first plant peptides with inhibitory activity against a matrixin.

Idiopathic gingival fibromatosis: a case report.

Idiopathic or hereditary gingival fibromatosis is a benign oral disorder characterized by enlargement of the oral gingival tissues. This article describes a case of a female child who exhibited a generalized gingival overgrowth in both arches at birth. Other causes of gingival overgrowth and the clinical, radiographic, and histopathologic characteristics are discussed. Treatment consisted of surgical removal of the hyperplastic fibrous tissue in a series of gingivectomies. Medical history, clinical examination, and histopathologic and genetic findings were essential to rule out other systemic abnormalities. This unusual case of nonsyndromic idiopathic gingival fibromatosis was followed for 5 years, and no recurrence was seen.

Proteomics of ionically bound and soluble extracellular proteins in Medicago truncatula leaves.

A large proportion of the apoplast proteome resides in the intercellular fluid (IF) or is ionically bound (IB) to the wall matrix. A combined analysis of IF and IB proteins of the Medicago truncatula leaf apoplast was performed. 2-DE analyses demonstrated the reproducible presence of 220 IF and 84 IB proteins in the apoplast. These two protein populations were largely distinct; 22 proteins could be spatially matched, but MALDI-TOF/TOF analyses suggested a considerably smaller number had common identities. MALDI-TOF/TOF characterisation identified 81 distinct proteins. Analyses of selected IF proteins (45) indicated 17 distinct proteins with mainly defence-related functions, whereas analyses of IB proteins (70) identified 63 distinct proteins of diverse natures, including proteins of non-canonical natures. The presence of non-canonical proteins in IB extracts is discussed in the light of evidence supporting a low level of contamination of purified walls from symplastic proteins. This work indicates that IB and IF proteins are functionally distinct fractions of the apoplast. The data obtained complements earlier studies of the Medicago proteome and therefore will be useful in future studies investigating the role of apoplastic proteins in plant processes.

Cloning and characterisation of a basic IAA oxidase associated with root induction in Vitis vinifera.

Changes in apoplastic peroxidases during auxin-induced in vitro rooting of cultured grapevine (Vitis vinifera L. cv. Touriga) stems have been studied. The largest increase in peroxidase activity (EC 1.11.1.7) was associated with the early stages of root initiation and could be attributed to an increase in activity of an apoplastic 36 kDa cationic peroxidase (PxB2). Relative to other peroxidases, PxB2 demonstrated high indole-3-acetic acid (IAA) oxidase activity and apparently contributed the majority of potential IAA oxidase activity in rooting tissues. The distribution of this peroxidase in developing roots additionally associates it with early phases of growth restriction. PxB2 was purified from cell wall extracts prepared from the basal 1 cm of rooting stems. Microsequencing and subsequent cloning of its corresponding 3' truncated cDNA (encoding 255 amino acids of the mature protein) revealed it to have a typical class III peroxidase structure. The results suggest that this class III peroxidase with IAA oxidase activity is important for the control of IAA levels during root initiation and development.