16 research outputs found
Aktivnost β-galaktozidaze i poligalakturonaze u kaši od tikvica (Cucurbita pepo L.) uskladištenoj pri niskim temperaturama
When fruits are exposed to chilling temperatures, enzymatic systems are affected and normal cell metabolism is altered; cell wall enzymes are the least studied in this respect. Our objective is to determine the effect of storage temperature and/or kind of tissue on the activity of the enzymes polygalacturonase (PG) and β-galactosidase (β-gal) in zucchini squash (Cucurbita pepo L.) subjected to 2.5 and/or 12 °C for 16 days. Exocarp and endocarp samples were analyzed every 4 days for PG and β-gal activities. The highest β-gal activity was found in the exocarp at 12 °C; in both tissues β-gal decreased with time at 2.5 °C, but increased at 12 °C. PG activity was higher in the endocarp (highest activity at 2.5 °C) than in the exocarp (highest activity at 12 °C). It was concluded that PG activity in the exocarp constitutes an adequate system for studying the relationship between chilling injury and cell wall biological activity.U plodovima izloženim niskim temperaturama mijenja se enzimska aktivnost što utječe na metabolizam stanica. Najmanje je istražen utjecaj niskih temperatura na enzime stanične stijenke. Istraživanje je provedeno da bi se ustanovio učinak temperature skladištenja na aktivnost enzima poligalakturonaze i β-galaktozidaze u kaši tikvica (Cucurbita pepo L.) tijekom 16 dana pri temperaturi od 2,5 ili 12 °C. Svaki četvrti dan u uzorcima egzokarpa i endokarpa ispitivana je aktivnost poligalakturonaze i β-galaktozidaze. Najveća aktivnost β-galaktozidaze pronađena je u uzorku egzokarpa pri 12 °C. U oba se tkiva aktivnost β-galaktozidaze smanjivala s vremenom pri temperaturi od 2,5 °C, a povećala pri 12 °C. Veća aktivnost poligalakturonaze bila je u endokarpu (najveća pri 2,5 °C) nego u egzokarpu (najveća aktivnost pri 12 °C). Zaključeno je da se praćenjem aktivnosti poligalakturonaze u egzokarpu može utvrditi odnos između oštećenja nastalih pri niskim temperaturama i biološke aktivnosti stanične stijenke
Total RNA quality of lyophilized and cryopreserved dormant grapevine buds
Background: Plant tissues must be preserved in their collection state,
especially for genome-wide expression profile studies. Lyophilization
is a feasible, affordable tool when fresh tissues cannot be shipped at
ultralow temperatures from their origin to the place of analysis. In
this study, the total RNA quality of dormant grapevine buds ( Vitis
vinifera L. cv. \u2018Flame Seedless\u2019) of freeze-dried
samples stored at room temperature conditions was evaluated and
compared to that of cryopreserved (-80\ub0C) grapevine buds. Results:
Good yield and quality of RNA were obtained from freeze-dried dormant
buds stored at room temperature for 0, 3 and 6 weeks after they were
lyophilized. Further experiments confirmed that the extracted total RNA
could be used for actin and \u3b2-tubulin PCR gene amplification.
Conclusion: High-quality RNA that is useful for downstream applications
was obtained from freeze-dried dormant grapevine bud tissue, similarly
to the RNA obtained from cryopreserved dormant grapevine buds
Compuestos Derivados de Ajo Como Agentes Inductores de Brotación en Cultivo Orgánico de Uva de Mesa
Viticulture is one of the most important economic activities in the
Northwest of Mexico. A major obstacle for the economic production is
the insufficient period of chilling temperatures. This problem leads to
poor budbreak, which in turn results in reduced yields. This problem is
aggravated when plants are cultivated using the organic farming system,
mostly because there are not organically approved restbreaking agents.
In this work different products derived from garlic ( Allium sativum
L.) were obtained and evaluated as stimulate budbreak agent of table
grape ( Vitis vinifera L.) cvs. Flame Seedless and Perlette. The
isolated compounds were chemically identified and include allicin,
diallyl disulfide, diallyl trisulfide, 3-vynil-[4H]-1,2-ditiin and
2-vynil-[3H]-1,3-ditiin, S-methyl cysteine sulphoxide, dimethyl
disulfide, dimethyl trisulfide and dimethyl thiosulfonate. Cuttings
with six buds were used to evaluate the compounds. After compounds were
applied, the cuttings were transferred to a growing chamber at 24
°C. All evaluated compounds promoted budbreak in the cuttings of
Flame Seedless and Perlette. The volatile compounds from S-methyl
cysteine sulfoxide promoted 100% of budbreak of both cultivars. The
compounds from garlic that stimulated budbreak in grapevines in this
work include sulphur in their molecule; therefore we propose that
sulphur could play a key role in breaking bud dormancy of grape
cultivars evaluated in this study.La viticultura es una de las principales actividades económicas en
el Noroeste de México. Entre los problemas que enfrenta esta
actividad está el período de frío insuficiente, lo que
lleva a una pobre brotación y consecuentemente una menor
producción. Este problema se agrava cuando se cultivan plantas por
el método orgánico, ya que no existen agentes inductores de
brotación aprobados para uso orgánico. En este trabajo se
aislaron diferentes compuestos derivados de ajo ( Allium sativum L.)
que se evaluaron para medir su efecto en la inducción de
brotación de yemas de vid ( Vitis vinifera L.) de los cultivares
Flame Seedless y Perlette. Los compuestos aislados de ajo e
identificados químicamente fueron: allicina, dialil disulfuro,
dialil trisulfuro, 3-vinil-(4H)-1,2-ditiin y 2-vinil-(3H)-1,3-ditiin,
S-metilcisteína sulfóxido, dimetil disulfuro, dimetil
trisulfuro y dimetil tiosulfonato. Se utilizaron estacas de seis yemas
para la evaluación de los compuestos; después de la
aplicación las estacas se desarrollaron en cámara de
crecimiento a 24 °C. Todos los compuestos evaluados promovieron la
brotación de las yemas de ambos cultivares. Los compuestos
volátiles de S-metilcisteína sulfóxido indujeron 100% de
brotación. Los compuestos derivados de ajo que indujeron la
brotación en este trabajo contienen sulpher en su molécula,
por lo que se deduce que el sulpher puede tener un importante papel en
el rompimiento de la dormancia de las yemas de vid de los cultivares
evaluados en este estudio
Activity of β-Galactosidase and Polygalacturonase in Zucchini Squash (Cucurbita pepo L.) Stored at Low Temperatures
When fruits are exposed to chilling temperatures, enzymatic systems are affected and normal cell metabolism is altered; cell wall enzymes are the least studied in this respect. Our objective is to determine the effect of storage temperature and/or kind of tissue on the activity of the enzymes polygalacturonase (PG) and β-galactosidase (β-gal) in zucchini squash (Cucurbita pepo L.) subjected to 2.5 and/or 12 °C for 16 days. Exocarp and endocarp samples were analyzed every 4 days for PG and β-gal activities. The highest β-gal activity was found in the exocarp at 12 °C; in both tissues β-gal decreased with time at 2.5 °C, but increased at 12 °C. PG activity was higher in the endocarp (highest activity at 2.5 °C) than in the exocarp (highest activity at 12 °C). It was concluded that PG activity in the exocarp constitutes an adequate system for studying the relationship between chilling injury and cell wall biological activity
Pectic and Galacturonic Acid Oligosaccharides on the Postharvest Performance of Citrus Fruits
Orange [Citrus sinensis (L.) Osbeck] and grapefruit (Citrus paradisi Macfad) citrus fruits are prone to develop different peel physiological disorders caused by storage at both chilling and nonchilling temperatures. The effect of galacturonic acid oligosaccharides (GAOs) and pectic oligosaccharides (POs) in reducing postharvest nonchilling peel pitting (NCPP), decay, and chilling injury (CI) in orange cv. Navelina and the effect of POs in reducing CI in grapefruit cv. Rio Red, were investigated. The incidence of these disorders was examined in fruits stored at chilling and nonchilling temperatures and at 90% to 95% relative humidity (RH). POs showed a better efficacy than GAOs in reducing postharvest losses in orange. The POs were able to reduce NCPP and decay in ‘Navelina’ fruits stored at 20 °C, irrespective of the fruit maturity stage. The application of 10 g·L−1 POs also reduced CI and the chilling-induced ethylene production in oranges and grapefruits maintained at the chilling temperature. Likewise, the decrease in ethylene production found in ‘Navelina’ fruits that developed NCPP during storage at the nonchilling temperature was related to lower peel damage. Moreover, results showed that POs do not induce an increase in ethylene when fruit are stored under conditions that do not cause stress-related injury to fruit. Therefore, POs efficacy in reducing postharvest physiological disorders is not likely mediated by ethylene. Overall results indicate that the application of POs may be an acceptable alternative to mitigate postharvest losses of citrus fruits.Araceli M. Vera-Guzman is a doctoral student in the graduate program of CIAD, and received a graduate fellowship from CONACyT, México. Part of this work was supported by the Spanish Ministry of Science and Technology (Research Grant AGL2013-41734-R and AGL2014-55802-R) and by the Generalitat Valenciana, Spain (Grant PROMETEOII/2014/027).Peer reviewe