Ethylene is a plant hormone involved in several physiological processes and regulates the plant d... more Ethylene is a plant hormone involved in several physiological processes and regulates the plant development during the whole life. Stressful conditions usually activate ethylene biosynthesis and signaling in plants. The availability of nutrients, shortage or excess, influences plant metabolism and ethylene plays an important role in plant adaptation under suboptimal conditions. Among the plant nutrients, the nitrogen (N) is one the most important mineral element required for plant growth and development. The availability of N significantly influences plant metabolism, including ethylene biology. The interaction between ethylene and N affects several physiological processes such as leaf gas exchanges, roots architecture, leaf, fruits, and flowers development. Low plant N use efficiency (NUE) leads to N loss and N deprivation, which affect ethylene biosynthesis and tissues sensitivity, inducing cell damage and ultimately lysis. Plants may respond differently to N availability balancing ethylene production through its signaling network. This review discusses the recent advances in the interaction between N availability and ethylene at whole plant and different organ levels, and explores how N availability induces ethylene biology and plant responses. Exogenously applied ethylene seems to cope the stress conditions and improves plant physiological performance. This can be explained considering the expression of ethylene biosynthesis and signaling genes under different N availability. A greater understanding of the regulation of N by means of ethylene modulation may help to increase NUE and directly influence crop productivity under conditions of limited N availability, leading to positive effects on the environment. Moreover, efforts should be focused on the effect of N deficiency or excess in fruit trees, where ethylene can have detrimental effects especially during postharvest.
Hibiscus rosa-sinensis L. is a popular ornamental species valued for its large brightly coloured ... more Hibiscus rosa-sinensis L. is a popular ornamental species valued for its large brightly coloured ephemeral flowers and has a range of health-promoting properties. The value of H. rosa-sinensis could be improved even further if there were ways to prolong the display life of its short-lived flowers, and to improve its frost tolerance. Development of an efficient plant transformation and regeneration procedure that allows introduction of genes into the plant will greatly facilitate this. Here we outline a transformation and regeneration procedure that is the first to produce transformed H. rosa-sinensis plants successfully. We first optimised callus induction and shoot regeneration efficiency. The highest shoot regeneration frequency of 66.7 % was achieved in the cultivar ‘Ruby’ when callus induced from axillary buds using a basal medium supplemented with 2.22 µM benzylaminopurine and 2.47 µM β-naphthoxyacetic acid was cultured on shoot regeneration medium. The frequency of shoot regeneration from callus was lower in ‘Ben James’ and absent in ‘Bright Light’, indicating genotypic differences. When axillary bud-derived callus of ‘Ruby’ was co-cultured with Agrobacterium tumefaciens harbouring a β-glucuronidase (GUS) reporter plasmid, 49 % of calli produced shoots on selection media. All tested plantlets were confirmed as transformed based on the presence of the GUS transgene in the genomic DNA and GUS activity measurements. Roots were induced on transgenic plantlets using half-strength basal medium supplemented with 2.85 µM indole-3-acetic acid. This simple protocol can be used to improve the ornamental, agronomic and health-promoting traits of H. rosa-sinensis hitherto recalcitrant to A. tumefaciens-mediated transformation.
A comparative study on functional leaf treats and the diurnal dynamics of photosynthetic processe... more A comparative study on functional leaf treats and the diurnal dynamics of photosynthetic processes was conducted on 2-year-old potted plants of two grape (Vitis vinifera L.) varieties (Aleatico, ALE, and Trebbiano giallo, TRE), exposed under controlled conditions to realistic concentrations of the pollutant gas ozone (80 ppb for 5 h day-1, 8:00-13:00 h, + 40 ppb for 5 h day-1, 13:00-18:00 h). At constitutive levels, the morphological functional traits of TRE improved leaf resistance to gas exchange, suggesting that TRE is characterized by a potential high degree of tolerance to ozone. At the end of the treatment, both varieties showed typical visible injuries on fully expanded leaves and a marked alteration in the diurnal pattern of photosynthetic activity. This was mainly due to a decreased stomatal conductance (-27 and -29% in ALE and TRE, in terms of daily values in comparison to controls) and to a reduced mesophyllic functioning (+33 and +16% of the intercellular carbon dioxide concentration). Although the genotypic variability of grape regulates the response to oxidative stress, similar detoxification processes were activated, such as an increased content of total carotenoids (+64 and +30%, in ALE and TRE), enhanced efficiency of thermal energy dissipation within photosystem II (+32 and +20%) closely correlated with the increased de-epoxidation index (+26 and +22%) and variations in content of some osmolytes. In summary, we can conclude that: the daily photosynthetic performance of grapevine leaves was affected by a realistic exposure to ozone. In addition, the gas exchange and chlorophyll a fluorescence measurements revealed a different quali-quantitative response in the two varieties. The genotypic variability of V. vinifera and the functional leaf traits would seem to regulate the acclimatory response to oxidative stress and the degree of tolerance to ozone. Similar photoprotective mechanisms were activated in the two varieties, though to a different extent.
Le tecniche agronomiche stanno evolvendo verso metodi di coltivazione organici, sostenibili e a b... more Le tecniche agronomiche stanno evolvendo verso metodi di coltivazione organici, sostenibili e a basso impatto ambientale. Lo scopo dell’agricoltura oggi è quello di ridurre gli input senza diminuire le produzioni e la loro qualità. I biostimolanti contengono composti bioattivi, in gran parte ancora sconosciuti, e sono in grado di aumentare la “nutrient use efficiency” delle piante e la tolleranza verso stress di tipo biotico e abiotico. Nelle colture orticole l’uso di biostimolanti permette di ridurre l’apporto di fertilizzanti senza compromettere la resa e la qualità del prodotto. Negli ortaggi da foglia sensibili all’accumulo di nitrati, come la rucola, i biostimolanti hanno la capacità di incrementare la qualità e mantenere il livello di nitrati sotto i limiti di legge. Nelle colture floricole i biostimolanti stimolano la crescita e anticipano la fioritura. English: The cultivation systems are developing towards new and low input systems, more environmental friendly and sustainab...
Il mantenimento delle caratteristiche ornamentali dei prodotti floricoli rappresenta una delle ca... more Il mantenimento delle caratteristiche ornamentali dei prodotti floricoli rappresenta una delle caratteristiche del loro successo commerciale. La durata post-raccolta dei fiori e del fogliame reciso è un parametro qualitativo molto importante nel settore floricolo. La caratterizzazione fisiologica e l'individuazione delle cause delle principali alterazioni fisiologiche permettono la scelta di strategie tecniche e soluzioni tecnologiche che possono preservare la qualità dei prodotti floricoli dal produttore al consumatore (Reid e Ferrante, 2002). La qualità delle piante fiorite in vaso è determinata dall'interazione di un complesso di fattori che contribuiscono a esprimere l'aspetto estetico e la capacità di conservare le caratteristiche ornamentali. Quindi, anche nel caso delle piante fiorite in vaso la durata dei fiori, intesa tanto in termini di numero che di persistenza e turnover, è naturalmente un requisito di qualità, che dipende essenzialmente dallo stato nutrizion...
Tra questi il floating system è di particolare interesse per la produzione di baby leaf. Il float... more Tra questi il floating system è di particolare interesse per la produzione di baby leaf. Il floating system (dal verbo to float, galleggiare) è una tecnica di coltivazione idroponica innovativa. Si tratta di un sistema di produzione in mezzo liquido statico in cui le piante sono allevate in pannelli di polistirolo provvisti di fessure riempiti con modesti quantitativi di substrato inerte (vermiculite, perlite etc.) o in contenitori alveolati (numero e dimensione degli alveoli variano a seconda della specie coltivata), galleggianti in vasche ...
Ethylene is a plant hormone involved in several physiological processes and regulates the plant d... more Ethylene is a plant hormone involved in several physiological processes and regulates the plant development during the whole life. Stressful conditions usually activate ethylene biosynthesis and signaling in plants. The availability of nutrients, shortage or excess, influences plant metabolism and ethylene plays an important role in plant adaptation under suboptimal conditions. Among the plant nutrients, the nitrogen (N) is one the most important mineral element required for plant growth and development. The availability of N significantly influences plant metabolism, including ethylene biology. The interaction between ethylene and N affects several physiological processes such as leaf gas exchanges, roots architecture, leaf, fruits, and flowers development. Low plant N use efficiency (NUE) leads to N loss and N deprivation, which affect ethylene biosynthesis and tissues sensitivity, inducing cell damage and ultimately lysis. Plants may respond differently to N availability balancing ethylene production through its signaling network. This review discusses the recent advances in the interaction between N availability and ethylene at whole plant and different organ levels, and explores how N availability induces ethylene biology and plant responses. Exogenously applied ethylene seems to cope the stress conditions and improves plant physiological performance. This can be explained considering the expression of ethylene biosynthesis and signaling genes under different N availability. A greater understanding of the regulation of N by means of ethylene modulation may help to increase NUE and directly influence crop productivity under conditions of limited N availability, leading to positive effects on the environment. Moreover, efforts should be focused on the effect of N deficiency or excess in fruit trees, where ethylene can have detrimental effects especially during postharvest.
Hibiscus rosa-sinensis L. is a popular ornamental species valued for its large brightly coloured ... more Hibiscus rosa-sinensis L. is a popular ornamental species valued for its large brightly coloured ephemeral flowers and has a range of health-promoting properties. The value of H. rosa-sinensis could be improved even further if there were ways to prolong the display life of its short-lived flowers, and to improve its frost tolerance. Development of an efficient plant transformation and regeneration procedure that allows introduction of genes into the plant will greatly facilitate this. Here we outline a transformation and regeneration procedure that is the first to produce transformed H. rosa-sinensis plants successfully. We first optimised callus induction and shoot regeneration efficiency. The highest shoot regeneration frequency of 66.7 % was achieved in the cultivar ‘Ruby’ when callus induced from axillary buds using a basal medium supplemented with 2.22 µM benzylaminopurine and 2.47 µM β-naphthoxyacetic acid was cultured on shoot regeneration medium. The frequency of shoot regeneration from callus was lower in ‘Ben James’ and absent in ‘Bright Light’, indicating genotypic differences. When axillary bud-derived callus of ‘Ruby’ was co-cultured with Agrobacterium tumefaciens harbouring a β-glucuronidase (GUS) reporter plasmid, 49 % of calli produced shoots on selection media. All tested plantlets were confirmed as transformed based on the presence of the GUS transgene in the genomic DNA and GUS activity measurements. Roots were induced on transgenic plantlets using half-strength basal medium supplemented with 2.85 µM indole-3-acetic acid. This simple protocol can be used to improve the ornamental, agronomic and health-promoting traits of H. rosa-sinensis hitherto recalcitrant to A. tumefaciens-mediated transformation.
A comparative study on functional leaf treats and the diurnal dynamics of photosynthetic processe... more A comparative study on functional leaf treats and the diurnal dynamics of photosynthetic processes was conducted on 2-year-old potted plants of two grape (Vitis vinifera L.) varieties (Aleatico, ALE, and Trebbiano giallo, TRE), exposed under controlled conditions to realistic concentrations of the pollutant gas ozone (80 ppb for 5 h day-1, 8:00-13:00 h, + 40 ppb for 5 h day-1, 13:00-18:00 h). At constitutive levels, the morphological functional traits of TRE improved leaf resistance to gas exchange, suggesting that TRE is characterized by a potential high degree of tolerance to ozone. At the end of the treatment, both varieties showed typical visible injuries on fully expanded leaves and a marked alteration in the diurnal pattern of photosynthetic activity. This was mainly due to a decreased stomatal conductance (-27 and -29% in ALE and TRE, in terms of daily values in comparison to controls) and to a reduced mesophyllic functioning (+33 and +16% of the intercellular carbon dioxide concentration). Although the genotypic variability of grape regulates the response to oxidative stress, similar detoxification processes were activated, such as an increased content of total carotenoids (+64 and +30%, in ALE and TRE), enhanced efficiency of thermal energy dissipation within photosystem II (+32 and +20%) closely correlated with the increased de-epoxidation index (+26 and +22%) and variations in content of some osmolytes. In summary, we can conclude that: the daily photosynthetic performance of grapevine leaves was affected by a realistic exposure to ozone. In addition, the gas exchange and chlorophyll a fluorescence measurements revealed a different quali-quantitative response in the two varieties. The genotypic variability of V. vinifera and the functional leaf traits would seem to regulate the acclimatory response to oxidative stress and the degree of tolerance to ozone. Similar photoprotective mechanisms were activated in the two varieties, though to a different extent.
Le tecniche agronomiche stanno evolvendo verso metodi di coltivazione organici, sostenibili e a b... more Le tecniche agronomiche stanno evolvendo verso metodi di coltivazione organici, sostenibili e a basso impatto ambientale. Lo scopo dell’agricoltura oggi è quello di ridurre gli input senza diminuire le produzioni e la loro qualità. I biostimolanti contengono composti bioattivi, in gran parte ancora sconosciuti, e sono in grado di aumentare la “nutrient use efficiency” delle piante e la tolleranza verso stress di tipo biotico e abiotico. Nelle colture orticole l’uso di biostimolanti permette di ridurre l’apporto di fertilizzanti senza compromettere la resa e la qualità del prodotto. Negli ortaggi da foglia sensibili all’accumulo di nitrati, come la rucola, i biostimolanti hanno la capacità di incrementare la qualità e mantenere il livello di nitrati sotto i limiti di legge. Nelle colture floricole i biostimolanti stimolano la crescita e anticipano la fioritura. English: The cultivation systems are developing towards new and low input systems, more environmental friendly and sustainab...
Il mantenimento delle caratteristiche ornamentali dei prodotti floricoli rappresenta una delle ca... more Il mantenimento delle caratteristiche ornamentali dei prodotti floricoli rappresenta una delle caratteristiche del loro successo commerciale. La durata post-raccolta dei fiori e del fogliame reciso è un parametro qualitativo molto importante nel settore floricolo. La caratterizzazione fisiologica e l'individuazione delle cause delle principali alterazioni fisiologiche permettono la scelta di strategie tecniche e soluzioni tecnologiche che possono preservare la qualità dei prodotti floricoli dal produttore al consumatore (Reid e Ferrante, 2002). La qualità delle piante fiorite in vaso è determinata dall'interazione di un complesso di fattori che contribuiscono a esprimere l'aspetto estetico e la capacità di conservare le caratteristiche ornamentali. Quindi, anche nel caso delle piante fiorite in vaso la durata dei fiori, intesa tanto in termini di numero che di persistenza e turnover, è naturalmente un requisito di qualità, che dipende essenzialmente dallo stato nutrizion...
Tra questi il floating system è di particolare interesse per la produzione di baby leaf. Il float... more Tra questi il floating system è di particolare interesse per la produzione di baby leaf. Il floating system (dal verbo to float, galleggiare) è una tecnica di coltivazione idroponica innovativa. Si tratta di un sistema di produzione in mezzo liquido statico in cui le piante sono allevate in pannelli di polistirolo provvisti di fessure riempiti con modesti quantitativi di substrato inerte (vermiculite, perlite etc.) o in contenitori alveolati (numero e dimensione degli alveoli variano a seconda della specie coltivata), galleggianti in vasche ...
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