1,721,134 research outputs found
Impiego dei fitoregolatori in viticoltura: potenzialità e problematiche.
No full textThe use of plant bioregulators to regulate
physiological process occurring during plant growth
and development may represent an important tool for
growers. In viticulture, hormone treatments have been
mainly addressed to the reproductive developmental
cycle, taking into account that grapevine vegetative
activity can be successfully controlled by training
systems and agricultural practices. In this review we
discuss the role of various hormones in the control of
inflorescence development and berry growth and ripening.
The control of these processes may have relevant
implications for disease control in the vineyard
considering that the susceptibility of different grape
cultivars to Botrytis bunch rot, powdery mildew and
downey mildew attacks is closely correlated with
bunch architecture. The timing and the extent of ripening
is of considerable scientific interest, but has also
implications for the various grape industries (fresh
market, winery logistic and processing, as well as
grape withering). In viticulture several bioregulators
can be used to regulate events of reproductive developmental
cycle. However, the most important applications
regard the use of gibberellins to modify inflorescence
length and bunch architecture as well as
berry size in seedless varieties, and abscissic acid,
ethylene and brassinosteroids to improve quality traits
of berries. Auxins can be mainly used as inhibitors of
ripening; therefore, they can be applied to delay the
vintage without significant changes of global quality of
berries. A delayed ripening can be also achieved by
spraying 1-methylcyclopropene, an inhibitors of ethylene
action. The knowledge of these effects has been
significantly improved in the last years thanks to the
increasing availability of information concerning the
molecular basis of hormone action. In the future, this
information could be used to develop new strategies
in the control of reproductive developmental cycle. In
addition, crystallography X-ray is an important tool to
elucidate the structure of plant hormone receptors
and thus to select, from chemical libraries, small biomolecules
able to interact with them. This is a crucial
point to develop new molecules with a lower synthesis
cost, which is often the main constraint on the introduction
of new plant bioregulators
Il controllo genetico-molecolare della maturazione e della qualità dei frutti
No full textIl completamento di progetti di sequenziamento dei genomi delle diverse specie frutticole consentirà di ampliare notevolmente le conoscenze sui processi di maturazione e sui meccanismi fisiologici e molecolari più rilevanti per la definizione della qualità dei frutti. Ciò permetterà di mettere a punto strumenti molecolari utilizzabili in programmi di miglioramento genetico assistito e di razionalizzare le tecnologie di produzione e di conservazione dei prodotti ortofrutticoli
The use of microarray μpeach 1.0 to investigate the transition from pre-climacteric to climacteric phase in peach fruit
No full textThe transition from preclimacteric to climacteric phase is a critical step during fruit development and ripening. An holistic approach to study this transition has been undertaken using the first peach microarray (μpeach 1.0) containing 4800 oligos corresponding to an equal number of genes expressed at preclimacteric and climacteric stages. Microarray hybridization indicated that 260 and 98 genes are up- and down-regulated, respectively. According to the TAIR Gene Ontology, genes have been classified into three main ontologies named cellular localization, molecular function and biological process. Considering the cellular localization the most significant up-and down-regulated gene products belong to cell wall and chloroplast. As far as cell wall is concerned major up-regulated genes encode pectinesterases and expansins, while down-regulation regards genes involved in cell wall growth and lignification. Among genes localized at chloroplast level a dramatic up-regulation of those controlling isoprenoids biosynthesis has been observed. Considering ontologies concerning molecular functions and biological process, a dramatic up-regulation has been detected for genes encoding transcription factors and enzymes involved in ethylene biosynthesis and action. Among transcription factors members of the APETALA and AUX/IAA families are the most represented, while within the family of ethylene receptors a peach new member has been described
Genomic tools for a better understanding of the fruit ripening process
No full textPurpose of the review: Increased understanding of fruit ripening is feasible with high-throughput methodologies for comprehensive transcriptome analyses. This article reviews main results gained by transcript profiling methods in the identification of genes involved in the regulation of fleshy-fruit ripening, and outlines potential applications of genomic tools developed in model species and already available in some important fruit crops.
Main findings: Global transcript profiling methods allowed the association of newly identified genes, such as some transcription factors, with the ripening syndrome. Furthermore, they helped in the functional characterisation of genes important for quality traits, such as aroma evolution and pigmentation. Comparative genomics carried out by digital analysis of expressed sequence tag repertoires and microarray analyses indicated that groups of genes responsible for regulatory mechanisms are shared between climacteric and non-climacteric fruits.
Direction for the future research: Gene sequences are important for fruit characteristics and can be useful in marker-assisted selection of new varieties. Further information on regulation of fruit ripening requires an extensive analysis of the proteome. Comparative proteomics is an efficient strategy that could be used to achieve this goal. The identification of differentially-expressed protein is becoming easier as a result of the rapid growth of plant DNA databases that allow association of a protein sequence with its cognate gene
Ethylene byosinthesis and kiwifruit softening following different post-harvest treatments
No full textThe softening of cv. Hayward fruit kept in air, air + C2H4, and CA (2% O2 + 5% CO2) + C2H4 at 20°C was related
to ethylene biosynthesis and action. Fruit softening (firmness below 40 N) occurred after 10, 14 and 21 days of
treatment with air + C2H4, air, and CA + C2H4, respectively. No relationship between whole fruit measurable ethylene
evolution and loss of firmness was found. In air and air + C2H4 treatments the ethylene rise generally appeared only
after the fruit had partially softened (firmeness about 50 N). No ethylene peak was observed, at least during the
experimental period, in fruit softened in CA + C 2H4. ACC content slightly increased in control fruit during ripening. A
higher ACC concentration was induced by exogenous ethylene only in fruit kept in air. ACC oxidase activity was
stimulated in air + C2H4 and reduced in CA + C2H4. In control fruit the highest ACC oxidase activity (over 40 nl
ethylene/gfw/h) was observed when the penetration force dropped below 50 N. The appearance of the ethylene peak,
which took place in the second phase of the ripening process was concurrent with a great increase of ACC oxidase
activity
Different postharvest conditions modulate ripening and ethylene biosynthetic and signal transduction pathways in Stony Hard peaches
Full text linkStony hard (SH) peaches are characterized, at ripening, by the maintenance of flesh firmness and the lack of ethylene production due to a reduced expression of Pp-ACS1. In a trial comparing melting flesh (MF, cv. ‘Summer Rich’) and SH (‘IFF331’ selection) fruit at two different postharvest temperatures (10 and 20 °C), unexpected behaviour was observed in SH peaches that displayed an increase in ethylene production and a decrease in flesh firmness when stored at 10 °C, a temperature regime basically ineffective in delaying ripening in MF fruit. This appeared to be the result of an induction of Pp-ACS1 transcription, making this genotype of particular interest for studying temperature stress physiology and ethylene-related ripening processes in peaches. Comparative expression analyses of genes involved in cell wall metabolism pointed out the presence of a negative (Pp-EG4), positive (Pp-endoPG) or no (one member of the PL family) relationship with ethylene at ripening. Results clearly showed that the last stage of firmness decrease (melting) only occurs in fruit producing ethylene and is associated with Pp-endoPG transcript accumulation. The expression of genes involved in ethylene biosynthesis and signalling pathways was evaluated using QRT-PCR. Pp-ACO1 appeared to be induced in SH kept at 10 °C but not at 20 °C. Transient increases in Pp-CTR1 and Pp-EIN2like gene expression have only been detected at the early stages of ripening in samples producing ethylene, indicating that a causal relationship might exist between ethylene and elements of its transduction pathway during peach fruit ripening
Brevi trattamenti in postraccolta con ULO e 1-MCP per il mantenimento della qualità delle pesche
No full textUn approccio biotecnologico avanzato per lo studio del ciclo di fruttificazione e della qualità del frutto
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