A trial established in 2003 at Upper Moutere in Nelson, New Zealand, was used to evaluate the effect of mussel shells as reflective mulch on Vitis vinifera L. cv. Pinot noir vine performance and fruit and wine quality. Shell mulch had several effects on the environment and vine growth as well as grape and wine composition in the 2006/2007 season. Soil under mulch was cooler compared to un-mulched control, but buffered the extremes in temperatures. Fruiting zone temperature over shells was slightly higher during the day and cooler at night, showing no effect on mean hourly temperature. Shell mulch reflected greater amounts of UV-A, UV-B and PAR radiation into the fruiting zone. Shell reduced weed growth compared to control. Leaf petiole and blade samples showed higher amounts of calcium compared to control. Leaf SPAD values were higher in the shell treatment during veraison, previous and postharvest, but lower post budburst. While date of budburst was not affected by treatments, dates of flowering and veraison appeared to be slightly advanced over shells. Fruit set was similar between treatments and was considered poorer in shell bunches due to a larger population of seedless berries. Vine growth was not affected in terms of the number of nodes laid at pruning, flower cluster and shoot number pre shoot thinning, early shoot growth and lateral shoots development. Vigour was not increased by shells as demonstrated by pruning weights, canopy density and trunk circumferences being similar, though internode lengths in shell shoots were greater in 2007 and lower in 2006. Berry weights, bunch weights and vine yields were lower in shell than control, though greater berry numbers were recorded. There were slight differences between treatments in fruit and wine composition. Grape pH only varied in the middle of the sampling time, being higher the 2nd week and lower the 3rd week in shell grapes and TA was greater at harvest time. However, °Brix was only higher in shell grapes in the middle of the sampling period, being similar to control at veraison and harvest. Peduncle lignification was delayed at veraison as well as at harvest time. Shell must after crushing was greater in Brix but similar to control in pH and TA. Similarly, shell wines pre bottling showed higher alcohol and no differences for pH and TA. HPLC-DAD analyses of commercial-scale and microvin wines showed consistent differences of the individual flavonoid composition. Shell microvin wines were greater than control in quercetin and resveratrol. However, commercial shell wines were lower in epicatechin, gallic acid, resveratrol, and catechin than control. Leaf phenolic composition was also different between treatments. However, further analyses by HPLC-MS in wines as well as in leaves are necessary to identify individual compounds. Total anthocyanins and total phenolics were no different between treatments. Sensory analyses of microvin and commercial shell wines exhibited consistently lower levels of green and unripe tannins, and greater smoothness and complexity as well. Further analysis by GC-MS and HPLC-MS is warranted. Shell mulch improved sensory characteristics of the resulting wines.

<p>This thesis focuses on mechanisms and processes underlying spatial patterns of resistance and virulence and on local adaptations in plant–parasite interactions. The model system used comprises the plant host Salix triandra, the pathogenic rust fungus Melampsora amygdalinae, the leaf beetle Gonioctena linnaeana, and the galler Pontania triandrae. In this work, I (1) emphasize the most important factors determining the outcome of a plant–pathogen interaction, and the types of systems in which local adaptations can be expected, (2) examine the resistance structures of different populations of S. triandra, and whether the leaf beetle G. linnaeana responds to the local conditions of the populations of S. triandra in Sweden, and (3) address whether the distribution of parasites on S. triandra can be explained by the plant content of secondary metabolites.</p><p>A review of several studies of the subject leads to the conclusion that adaptation of pathogens to their local hosts is more likely to be found in systems in which the pathogen is host-specific, non-systemic, and has a larger dispersal range and evolutionary potential than its host does. Furthermore, the scale of the study must be adjusted to that of the pathogen’s local population distribution. In addition, the temporary nature of host–pathogen interactions influences the importance of sample size, and too-small sample sizes can lower the chance of finding local adaptations, even though they may have evolved in a given system. The results of an inoculation experiment using material from physically isolated natural populations of S. triandra and M. amygdalinae confirm the importance of previous conclusions.</p><p>Spatial variation in the resistance structure of S. triandra also has effects on the insect herbivore G. linnaeana, which has responded by adapting to the local hosts. However, local differences in secondary chemistry affect different parasites in different ways, and while P. triandrae is attracted by high levels of phenolic compounds, including tannins, M. amygdalinae and G. linnaeana are more rarely found on plant individuals with high concentrations of tannins. In addition, brood deposition by adult females of G. linnaeana and the performance of larvae are positively affected by luteolin-7-glucoside and an additional unidentified flavonoid, whereas they are negatively affected by the presence of (+)-catechin and high levels of tannins.</p><p>Our results also show that plants traits that provide resistance to one type of parasite do not necessarily provide resistance to others. This indicates that different natural enemies potentially assert divergent selection pressure on S. triandra phenotypes which can be important for maintaining phenotypic variation in plant species.</p>

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio. / February 2007

Τα φύλλα κάποιων φυτών γίνονται παροδικά κόκκινα, λόγω της συσσώρευσης ανθοκυανινών. Εξετάστηκαν δύο από τις πολλές υποθέσεις που έχουν διατυπωθεί για το ρόλο των χρωστικών αυτών στα φύλλα: ο φωτοπροστατευτικός τους ρόλος και η εμπλοκή τους στις σχέσεις φυτών και φυτοφάγων εντόμων. Χρησιμοποιήθηκαν δύο είδη φυτών (Quercus coccifera και Cistus creticus) τα οποία παρουσιάζουν ενδοειδική ποικιλομορφία όσον αφορά στη συσσώρευση ανθοκυανινών στα φύλλα τους. Στο Q. coccifera, τα νεαρά φύλλα κάποιων ατόμων είναι κόκκινα και κάποιων άλλων πράσινα, ενώ κατά την ενηλικίωση τους γίνονται όλα πράσινα. Τα ώριμα φύλλα του C. creticus το καλοκαίρι είναι πράσινα (“πράσινη” περίοδος) αλλά συσσωρεύονται παροδικά ανθοκυανίνες στα ώριμα φύλλα κάποιων θάμνων κατά τη περίοδο του χειμώνα (“κόκκινη” περίοδος), ενώ γειτονικά άτομα παραμένουν πράσινα. Συγκρίθηκαν παράμετροι του in vivo φθορισμού της χλωροφύλλης, τα επίπεδα των συστατικών του κύκλου των ξανθοφυλλών και των ολικών φαινολικών, τα φάσματα ανακλαστικότητας και η ένταση της φυτοφαγίας, σε κόκκινα και πράσινα φύλλα από αντίστοιχους φαινοτύπους που αναπτυσσόντουσαν στο ίδιο ενδιαίτημα. Δεν διαπιστώθηκε κάποιο συγκριτικό πλεονέκτημα (ή μειονέκτημα) των ανθοκυανικών φύλλων όσον αφορά στη φωτοσυνθετική τους λειτουργία ή στην ανθεκτικότητά τους έναντι της φωτοαναστολής, στις συνθήκες που αναπτύσσονται. Στα διαφορετικού χρώματος, νεαρά φύλλα του Q. coccifera, είναι σαν να γίνεται ένας “συμβιβασμός” όπου στα κόκκινα φύλλα φτάνει λιγότερο φως στους χλωροπλάστες (ή/και λειτουργούν οι ανθοκυανίνες ως αντιοξειδωτικά), ενώ τα πράσινα φύλλα έχουν μεγαλύτερη δυνατότητα για μη φωτοχημική απόσβεση λόγω μεγαλύτερης συγκέντρωσης συστατικών του κύκλου των ξανθοφυλλών. Στο C. creticus, κατά την “πράσινη” περίοδο τα μελλοντικά ερυθρά φύλλα παρουσιάζουν φωτοσυνθετική και φωτοπροστατευτική κατωτερότητα, σε σχέση με τα φύλλα του πράσινου φαινοτύπου, που όμως δεν τους δημιουργεί πρόβλημα, όσο οι περιβαλλοντικές συνθήκες είναι ευνοϊκές. Κατά τη δυσμενή εποχή του χειμώνα, τα πράσινα φύλλα αυξάνουν την ικανότητα τους για μη φωτοχημική απόσβεση, ενώ τα κόκκινα όχι. Μπορεί σε αυτή την περίπτωση οι ανθοκυανίνες να αποτελούν μια προσαρμογή ώστε να αντισταθμίζεται αυτή η κατωτερότητα και να μειώνεται ο κίνδυνος φωτοαναστολής. Ωστόσο, τα νεαρά κόκκινα φύλλα του C. coccifera, είχαν υποστεί λιγότερες απώλειες από φυτοφάγα. Η μη ύπαρξη διακυμάνσεων στο φάσμα ανακλαστικότητας των κόκκινων φύλλων στην περιοχή 400-700 nm, σε συνδυασμό με τις δυνατότητες της χρωματικής όρασης πολλών φυτοφάγων εντόμων, υποδεικνύει ότι τα ερυθρά φύλλα πιθανόν να μην μπορούν εύκολα να εντοπιστούν από τους θηρευτές τους. Επίσης, κάποια φυλλοβόρα έντομα μπορεί να αποφεύγουν τα κόκκινα φύλλα, γιατί εκεί γίνονται περισσότερο ευδιάκριτα από τα αρπακτικά. Η αυξημένη συγκέντρωση των κόκκινων φύλλων σε φαινολικά μπορεί να αποθαρρύνει την περεταίρω κατανάλωση μετά από τυχαία προσέγγιση. / Leaves of some plants are transiently red due to anthocyanin accumulation. Among the many hypotheses for the function of foliar anthocyanins, two are tested in this field study: the sun screen, photoprotective function against excess visible light and the handicap signal against herbivory. Two plant species (Quercus coccifera and Cistus creticus) were used which display intraspecies variation in the expression of the anthocyanic character. Young leaves of some individuals of Q. cocifera are transiently red due to anthocyanin accumulation, while redness disappears upon maturation. Mature leaves of C. creticus are green during summer (“green” period) but in some individuals they turn transiently to red during winter (“red” period), while neighboring individuals remain green. In vivo chlorophyll fluorescence parameters, xanthophyll cycle pool sizes, reflectance spectra, total phenolics and extent of herbivory were compared in green and red leaves sampled from the corresponding phenotypes occupying the same habitat. An appreciable photosynthetic and photoprotective superiority (or inferiority) of anthocyanic leaves in both plant species under field conditions was not found. It seems that there is a compromise in differently coloured young leaves of Q. coccifera where red leaf chloroplasts enjoy less light due to its attenuation by anthocyanins (and/or anthocyanins participate in photoprotection through their anti-oxidant capacity) while green leaf chloroplasts are better equipped to dissipate excess light as heat through their higher size of xanthophyll cycle pool. During the “green” period, future red leaves of C. creticus show photosynthetic and photoprotective inferiority compared to the leaves of the green phenotype which is possibly insignificant for plant performance during the favourable period of the year. During the winter stress green leaves increase their ability for non-photochemical quenching while red phenotypes do not. In this case, anthocyanins may be an adaptation to compensate for this deficiency and alleviate the risk of photodamage. However, young red leaves of Q. coccifera are less attacked by insect consumers. The leveling of reflectance in anthocyanic leaves throughout the 400-570 nm band together with the spectral discriminating capabilities of leaf eating insects, may make red leaves less discernible to some insects. Furthermore, some insect herbivores may avoid red leaves because there are more discernible to predators. Incidental attack may be a posteriori discouraged due to the high phenolic investment of red leaves.

Berry ripening in lowbush blueberry (Vaccinium angustifolium Ait.) is influenced by developmental, physiological and climatic factors resulting in a heterogenous mix of maturities at harvest. This study characterizes the physico-chemical changes which occur during fruit ontogeny and links ripening patterns to micoclimate. Individual clones in five commercial fiels were followed in the 2006 and 2007 growing seasons. Phenolic acids, flavonols, and flavan-3-ols decreased and anthocyanins increased with maturity. Peak maturity consistently occurred at 1200 accumulated growing degree days (GDD). There was a sharp decline in fruit retention at the end of the growing season suggesting a date after which harvested yield declines but no consistent pattern was detected between years or fields.The consistency of GDD accumulation in relation to ripening pattern suggests GDDs can be used as a predictive ripening index. The physico-chemical nature of ripe berries indicates ripe berries could be harvested earlier than is currently the practice.

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio.

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio.

In previous studies silicon has been associated with reduced disease severity and incidence, the enhanced accumulation of phenolic compounds and lignin, and with changes in the defence-related enzyme activity and transcript abundance of defence and stress related genes. All of these aspects of plant defence were considered in this study on cotton infected with Fusarium oxysporum f. sp. vasinfectum (Fov), and the results obtained have greatly enhanced our understanding of the effects of silicon on this interaction. In all experiments conducted, defence responses were only significantly enhanced by silicon treatment following inoculation with Fov, strongly suggesting that silicon can prime defence responses in cotton infected with Fov. Sicot F-1 was the cultivar most resistant to Fov infection at the commencement of this research, whilst Sicot 189 was considered to have moderate resistance to the pathogen. Vascular discolouration was significantly reduced in the more resistant cultivar, Sicot F-1 following treatment with potassium silicate, compared to mock inoculated plants and inoculated plants treated with potassium sulphate or calcium sulphate. No significant differences between treatments were observed in the moderately resistant cultivar, Sicot 189, though further trials may need to be conducted to confirm this result. In both cultivars, silicon content was significantly greater in plants which had been treated regularly with liquid potassium silicate, rather than with calcium silicate powder. Histological investigation of cotton infected with Fov, with and without silicon treatment, was conducted to ascertain the effects of this element on the accumulation of fungitoxic phenolic compounds, cell ultrastructural changes and fungal infection structures. Fov proliferated through the cortex and stele of plants from both the resistant (Sicot F-1), and moderately resistant (Sicot 189) cultivars, regardless of silicon treatment. However, defences were more rapidly and intensely induced in endodermal and vascular regions of inoculated, potassium silicate treated Sicot F-1 plants. Significantly more phenolic compounds were present at seven days post infection (dpi) in root extracts of inoculated, potassium silicate treated Sicot F-1 plants. Phenolic compounds were not significantly increased in inoculated, potassium silicate treated root extracts of Sicot 189 plants at three or seven dpi. Lignin assays demonstrated that the dry weight percentage of lignin in root material from inoculated, potassium silicate treated Sicot F-1 plants was significantly higher than that of extracts from inoculated plants not receiving silicon treatment at three dpi. This trend was also observed at seven dpi; however lignin content was not significantly different in this case. Percentage lignin content in the roots of Sicot 189 plants was not significantly different between inoculated potassium silicate treated plants and those not treated with silicon. Histological alterations were not observed in mock inoculated water or potassium silicate treated plants, nor were any significant increases in phenolic compounds or lignin accumulation detected in control treatments not inoculated with the pathogen. The expression of several defence related genes was assessed with quantitative reverse transcriptase real-time polymerase chain reaction. The results obtained verify that potassium silicate can enhance defence responses in Sicot 189 and Sicot F-1 plants inoculated with Fov, with silicon having a more pronounced effect on the more resistant cultivar, Sicot F-1. Genes upregulated at three and four dpi in potassium silicate treated, Fov inoculated Sicot F-1 plants included peroxidase, cadinene synthase and polygalacturonase inhibiting protein (PGIP), with peroxidase associated with phenol oxidation and lignification and cadinene synthase with phytoalexin biosynthesis. Osmotin-like protein and chitinase class I were consistently upregulated in potassium silicate treated, inoculated Sicot 189 plants; both genes coding for pathogenesis related (PR) proteins, with chitinase also classified as an antifungal protein. In both cultivars, silicon treatment without Fov inoculation did not result in the significant up-regulation of any of the defence genes assessed, providing further evidence for the role of silicon in priming in this interaction. The activities of three defence related enzymes, peroxidase, chitinase and β-1, 3- glucanase was assessed in root and shoot material by colourimetric assays. Regular application of potassium silicate significantly increased the activity of peroxidase in root extracts from the highly resistant cultivar Sicot F-1, at three, four and seven dpi with Fov, and in root extracts from the moderately resistant Sicot 189 at three and four dpi. Significant increases in chitinase activity in inoculated, silicon treated Sicot 189 plants were observed in root extracts at three dpi, and in shoot extracts at four dpi. Soluble potassium silicate treatment resulted in significant increases in β-1, 3- glucanase activity in Sicot 189 root extracts at four dpi. Few significant differences between treatments in terms of chitinase and β-1, 3- glucanase activity were detected in Sicot F-1 plants, though higher levels of each of these enzymes were present in root and shoot extracts from this cultivar. In this study the effects of acibenzolar-S-methyl, applied in the form of Bion®, on defence gene expression and enzyme activity in cotton infected with Fov were more pronounced in plants cultivated from treated seed, rather than in plants treated via foliar spray; a finding which is particularly relevant to the industry presently. Significant up-regulation of chitinase class I, peroxidase, and β-1, 3-glucanase transcripts and enzyme activities occurred in the Bion® seed soak treatment with Fov inoculation compared to all other treatments. It was possible to compare the actions of silicon with those of Bion® in this study. Bion® primed defence responses in cotton infected with Fov, in a manner similar to that observed in silicon treated cotton. The use of silicon and Bion® treatments, both alone and in combination as part of integrated disease management programmes, may potentially contribute to increased protection against this pathogen in Australian cotton fields in the future.

The present study aims to determine the antioxidant capacity of the ethanolic extracts of husk fiber of four coconut (Cocos nucifera L.) varieties (yellow dwarf, green dwarf, giant and hybrid), aiming to verify their possible utilization as natural antioxidants. For this, their total phenolic content, radical DPPH• scavenging activity, reducing ability towards iron ions (FRAP) and copper ions (CUPRAC) and inhibition of lipid peroxidation using a biomimetic membrane system were analysed. The electrochemical investigation using a glassy carbon and a modified glassy carbon electrode, and the identification of some chemical constituents were performed by cyclic and differential pulse voltammetry and liquid chromatography coupled with UVVIS spectrometry (CLAE-UV/DAD) and mass spectrometry, respectively. The higher value of total phenolic content was found for the hybrid variety: 531 ± 24 mg GAE g-1 dry extract and the lowest was for the green dwarf with 58 ± 9 mg GAE g-1 dry extract. The ability of the extracts to scavenge DPPH• radicals was in the order giant> yellow dwarf > hybrid > green dwarf and IC50 values varied from 8.6 to 55.9 μgmL-1. All varieties showed reducing potential by the use of FRAP and CUPRAC methods, with the lowest performance obtained for the green dwarf variety. Through the use of mimetic biomembranes, ethanolic extracts of coconut husk fibers were shown to protect lipids against oxidative damage independent of the variety. Cyclic voltammetric studies of the ethanolic extracts on glassy carbon electrode confirmed the presence of easily oxidized compounds, and the high antioxidant capacity of the varieties. This was expressed as mg quercetin equivalents g-1 dry extract and ranged from 25.9 – 53.5 mg QE g-1 dry extract using a glassy carbon xanthurenic acid modified electrode (GCE/MWCNT/ poly-Xanthurenic Acid). The investigation of phenols using CLAE-UV/DAD revealed the presence the catechin, quercetin, chlorogenic, vanillic, ferulic, caffeic and gallic acids. Our findings suggest that these extracts can be an important source of natural antioxidants for use in food and possibly in the pharmaceutical and cosmetic industry, aggregating value to the enormous amount of waste from the coconut industry. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O presente estudo teve como objetivo determinar a capacidade antioxidante dos extratos etanólicos das fibras da casca de coco (Cocos nucifera L.) das variedades anão amarelo, anão verde, gigante e híbrido, visando sua possível utilização como antioxidante natural. Para isso, foram analisados o conteúdo total de fenóis, as atividades sequestradora do radical DPPH• , redutora frente aos íons de ferro (FRAP), e íons de cobre (CUPRAC) e a inibição da lipoperoxidação utilizando um sistema de membranas biomimético. Fez-se investigação eletroquímica utilizando eletrodo de carbono vítreo e eletrodo de carbono vítreo modificado, assim como a identificação de alguns constituintes químicos, por meio da técnica de cromatografia líquida acoplada ao espectrômetro UV-Vis (CLAE – UV/DAD). Para o conteúdo total de fenóis, os maiores valores foram obtidos para a variedade híbrido (531 ± 24 mg EAG g-1 extrato seco) e o menor foi para a variedade anão verde (58 ± 9 mg EAG g-1 extrato seco). A habilidade dos extratos para sequestrar o radical DPPH• foi estabelecida na seguinte ordem: gigante > anão amarelo > híbrido > anão verde e os valores de IC50 variaram de 8,6 a 55,9 μg mL-1. Todas as variedades mostraram potencial redutor para os métodos FRAP e CUPRAC, com o menor desempenho para a variedade anão verde. Através do sistema do uso de membranas biomiméticas, os extratos etanólicos da fibra da casca de coco mostraram proteção contra os danos oxidativo lipídicos, independente da variedade. Estudos de voltametria cíclica dos extratos etanólicos em eletrodo de carbono vítreo confirmaram a presença de compostos facilmente oxidáveis, e elevada capacidade antioxidante das variedades. Esta capacidade foi expressa em miligramas equivalentes de quercetina (Q) por grama de extrato seco e variou de 25,9 – 53,5 mg EQ g-1 usando um eletrodo de carbono vítreo modificado (ECV/MWCNT/poliácido xanturênico). Na investigação de compostos fenólicos por CLAE-UV/DAD verificou-se a presença de quercetina, ácido clorogênico, ácidos vanílico, ferúlico, cafeíco, gálico, e catequina. Nosso trabalho sugere que esses extratos podem ser antioxidantes importantes para o enriquecimento na dieta humana, indústrias farmacêuticas e de cosméticos, agregando valor à enorme quantidade de resíduos gerados na indústria do coco.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to investigate the influence of different parameters (concentration of solvent, time, temperature and power) in extraction methods (focused microwave, conventional and ultrasound) bioactive compounds in blueberries, seeking higher yield of compounds biativos, antioxidant and antimicrobial activity of the extracts.The extracts were characterized regarding the phenolic compounds, flavonoid and anthocyanins content. The in vitro antioxidant activity was quantified by the methods of DPPH, ABTS, FRAP, and β-carotene, was calculed the IC50 and evaluated the antimicrobial activity.The results for focused microwave extraction generally indicated that the antioxidant activity (FRAP, ABTS and DPPH), total phenolics and total anthocyanins showed a positive linear trend in relation to the extraction temperature, with no significant difference between the solvent concentrations (60 and 80%). The IC50 and β-carotene showed the greatest inhibition at 60°C at solvent concentrations of 60% and 80%, respectively. The flavonoids showed no significant difference in terms of the extraction temperature or the concentration of solvent that was used. No antimicrobial activity was detected in the extracts in relation to the tested microorganisms. In the conventional method of extracting the best extraction conditions for phenolic compounds, flavonoids and anthocyanin employed 60% solvent, 60 minutes at 40ºC; however, the anthocyanins did not suffer any influence from time and temperature. The best results for the antioxidant activity using the DPPH and FRAP methods were obtained with 60% solvent, 30 minutes at 30ºC, and the DPPH was not influenced by temperature. Regarding ABTS+ the best results were reached with 60% solvent, 120 minutes, at 40ºC, while the β-carotene required 80% solvent at 40ºC, regardless of the time. The different extracts tested did not show antimicrobial activity. Ultrasound provided better phenolic extraction conditions, flavonoids and anthocyanins using 60% solvent, 20 minutes and 80 watts of power, and phenolic compounds not influenced by the power and flavonoids were not affected by the solvent. The antioxidant activity by DPPH and IC50 showed the best results com 60% solvent, 60 minutes and 80 W of power, the same conditions were found for β-carotene, but with 20 minutes of extraction. FRAP methodology is presented more efficient solvent 60%, 60 minutes and 220W power, whereas for the ABTS assay was 80% solvent and 80 W of power, independent of the extraction time. The extracts obtained through different methods of extraction showed no antimicrobial activity. However, the study confirms the antioxidant capacity of blueberries, which can be used as a functional ingredient or as a natural antioxidant in the preparation of food products. / Este trabalho teve como objetivo investigar a influência de diferentes parâmetros (concentração de solvente, tempo, temperatura e potência) nos métodos de extração (assistida por micro-ondas focalizada, convencional e por ultrassom) de compostos bioativos de mirtilo, visando maior rendimento dos compostos biativos, atividade antioxidante e antimicrobiana dos extratos. Os extratos foram caracterizados quanto o teor de fenólicos totais, flavonoides totais e antocianinas totais. As atividades antioxidante in vitro foram quantificadas pelos métodos de DPPH, ABTS, FRAP e β-caroteno, foi calculado o IC50 e avaliada a atividade antimicrobiana. Os resultados encontrados para a extração através das micro-ondas focalizadas apontam que as atividades antioxidantes medidas por FRAP, ABTS+ e DPPH, compostos fenólicos totais e antocianinas totais apresentaram uma tendência linear positiva em relação à temperatura de extração, sem diferença significativa entre as concentrações dos solventes (60 e 80%). O IC50 e o β-caroteno apresentaram maior inibição na temperatura de 60°C, porém estes somente nas condições de solvente 60% e 80%, respectivamente. Os flavonóides não tiveram diferenças significativas na temperatura de extração e nem no solvente utilizado. No método convencional de extração as melhores condições de extração para os compostos fenólicos, flavonóides e antocianinas foi utilizando 60% de solvente, 60 minutos e à 40ºC, porém as antocianinas, não sofreram influencia do tempo e da temperatura. O melhores resultados para as atividades antioxidantes, pelos métodos DPPH e FRAP, foram obtidos com solvente 60%, 30 minutos e à 30ºC, sendo que o DPPH não foi influenciado pela temperatura. Para o ABTS+ os melhores rendimentos foram com 60% solvente, 120 minutos e à 40ºC, enquanto que para o β-caroteno, 80% de solvente a 40ºC, independentemente do tempo. O ultrassom proporcionou melhores condições de extração de fenólicos, flavonóides e antocianinas utilizando 60% de solvente, 20 minutos e 80 W de potência, sendo que os compostos fenólicos não sofreram influência da potência e os flavonoides não foram influenciados pelo solvente. A atividade antioxidante pelo método DPPH e o IC50 apresentaram os melhores resultados com 60% de solvente, 60 minutos e 80 W de potência, as mesmas condições foram encontradas para o β-caroteno, porém com 20 minutos de extração. A metodologia de FRAP apresentou-se mais eficiente com solvente 60%, 60 minutos e 220W de potência, enquanto que para o método ABTS+ foi com 80% de solvente e 80 W de potência, independente do tempo de extração. Os extratos obtidos através das diferentes metodologias de extração não apresentaram atividade antimicrobiana. Contudo, o estudo confirma a capacidade antioxidante do mirtilo, podendo este ser utilizado como ingrediente funcional ou como antioxidante natural na elaboração de produtos alimentícios.