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Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte and some varieties are able to cope with salinity levels as high as those present in sea water. Due to its traditionally broad cultivation area (from the salt flats of the Andes at 3,800 m above sea level to the seacoast and from Colombia down to southern Chile), there is a very wide range of quinoa cultivars adapted to specific conditions displaying a broad genetic variability in stress tolerance. For this reason, quinoa offers a valuable source of germplasm for breeding new cultivars adapted to stressful environments in diverse geographical conditions and for identifying mechanisms potentially useful in breeding tolerant glycophytes. In Chile, the genetic distance between highland (altiplano) and coastal cultivars of quinoa has been assessed but their responses to salinity are less known. In the present work, the response to salt treatments (0, 100 and 300 mM NaCl) was investigated in one altiplano landrace, R49, and two coastal ones, VI-1 and VR (from central and southern Chile, respectively). Salt treatment caused a significant increase in Na+ concentrations in all plant organs; the Na+ concentration accumulated in leaves under 300 mM salt was highest in VI-1 and was ca. 1.5- to 3-fold higher in leaves and roots of plants grown under 300 mM NaCl than 100 mM NaCl. Growth was significantly inhibited by the lower salt concentration only in R49, whereas 300 mM NaCl reduced growth also in VI-1 and VR, albeit to a lower extent than in R49. The concentrations of photosynthetic pigments, total phenolics and flavonoids were differentially affected by salt in leaves of the three cultivars. Seed production at harvest was unaffected or even enhanced (VR) by 100 mM NaCl relative to controls, while with 300 mM it was reduced in R49 and VI-1 (ca. 80% and 40% inhibition, respectively) but was not affected in VR. The germinability of seeds collected from plants grown in the presence (100 or 300 mM) or absence (0 mM) of NaCl was tested on agar plates containing 0-500 mM NaCl. Results showed that the response varied between landraces with VR exhibiting the highest sensitivity (germination was inhibited even by 100 mM NaCl). Seed protein profiles (SDS-PAGE of total proteins and the amount of the 11S seed storage protein chenopodin) were compared among different cultivars not treated with salt and the effect of salt treatments on protein profile were checked in the frame of the single cultivar; this allow to compare the differences due to the genotype and also the plant response to the salt treatments.

Quinoa's adaptation was tested in Mali, West Africa, where the difficult agroclimatic conditions are similar to those in central northern Chile. The traditional varieties used were predominantly from Chile ('A64', 'BO25', 'BO78', 'PRP', 'PRJ', 'UDeC9', 'R49', 'VI-1', 'Regalona', 'Mix'), plus two crop cultivars from Argentina ('Roja Tastina' and 'Sajama') and one varietyfrom Bolivia. Trials began in 2007 and continue today. They tested sowing in the rainy season (June-Oct.) and in the dry season (Nov.- Mar.). Pests, diseases and yields were assessed, taking into account also the grain storage conditions and more sustainable soil management (compost). Some Altiplano cultivars were recalcitrant ('A64', 'R49' and 'MIX'), while the traditional varieties from central southern Chile gave satisfactory yields (1-2 tonnes/ha). Ideally, seeds should be sown each season to avoid a reduction in germination vigour which is caused by the ambient humidity and high temperatures characteristic of in situ storage in tropical zones. The crop cycle is 90-100 days for the accessions from Chile and up to 108-119 days for the accessions from Argentina. The panicles can be attacked by fungal diseases that reduce productivity in the rainy season. The presence of phytophagous insects (Bemisia, Aphis and Aspavia genera) was observed, as well as Coccinellidae, which are their natural predators in biological control. Quinoa has the potential to improve the supply of high quality protein in Africa. Pests in the rainy season and insect infestation can be controlled by adopting ecological management practices, using saponins from the same quinoa varieties. The limiting factor is the energy requirement for using water (not readily available in the dry season) and for mechanized threshing. The population's use and acceptance of quinoa can be expected to be high, on the basis of past experience introducing other crops from America (potato, maize and tomato) to this continent and given the culinary similarity with millet and rice.

Salinity is today amongst the most widespread constraints in irrigated agriculture. Thus, salt tolerance is an agronomically important trait that is receiving increasing attention among scientists worldwide. Quinoa is tolerant to soil salinity and other adverse environmental factors, hence attracting the attention of researchers as a possible crop in a changing world scenario in which scarcity of water resources and increasing soil and water salinization are the primary causes of crop loss. Quinoa's exceptional tolerance to salinity, frost, drought and other types of abiotic stress also makes it a model species for investigating cellular, physiological, bio-molecular and morphological mechanisms at the basis of stress tolerance in halophytes and in plants as a whole. There are quinoa ecotypes adapted to valley, altiplano, salt desert, sea level and tropics, which display broad genetic variability in salinity tolerance. For this reason, quinoa represents a valuable resource for selection of the most suitable material and for breeding new varieties adapted to different environmental and geographical conditions. In this chapter, scientific studies on salinity tolerance in quinoa conducted in the last decade by numerous research groups operating in at least nine different countries are described. We focus on studies in which different quinoa genotypes are compared for their response to saline conditions, demonstrating that salt tolerance is a complex, multigenic trait involving a plethora of physiological and structural adaptations. Results available up to now regarding the effect of salinity on the nutritional properties of quinoa are reported. (Texte intégral)

An increasing number of studies have been performed in recent years in Italy on quinoa (Chenopodium quinoa Willd.). Interest in this Andean seed crop is mainly due to its resistance to the abiotic stresses affecting Mediterranean agro-ecosystems, in particular drought and salinity, and to the high nutritional value of its seeds. The principal research activities in Italy currently focus on the agronomic, biological and nutritional aspects of quinoa. Several field trials were carried out at CNR-ISAFoM in Ercolano (Napoli) to evaluate, in terms of growth, yield and physiological aspects, the adaptability of quinoa to Italian pedoclimatic conditions, and the crop’s response to different agronomic management practices. Post-harvest chemical and product analyses were also performed to evaluate seed quality and aptitude for food processing. Quinoa’s tolerance to salinity stress was investigated under controlled environmental conditions at the University of Bologna, where morphological and metabolic responses were analysed. All of these studies were conducted within national and international research projects with the collaboration of foreign research centres (CEAZA, Chile) and universities (University of Copenhagen), mainly using plant material selected in Denmark or sourced from the Andean region. This chapter describes the results of the main research activities carried out in the last decade by Italian institutions and discusses the potential for the introduction of quinoa cultivation in Italian cropping systems.

Salinity is today one of the most widespread constraints in irrigated agriculture. Thus, salt tolerance is an agronomically important trait receiving increasing attention among scientists worldwide. Quinoa is tolerant to soil salinity and other adverse environmental factors, hence it attracts the attention of researchers as a possible crop in a changing world scenario in which scarcity of water resources and increasing soil and water salinization are the primary causes of crop loss. Quinoa’s exceptional tolerance to salinity, frost, drought and other types of abiotic stress also makes it a model species for investigating cellular, physiological, biomolecular and morphological mechanisms at the basis of stress tolerance in halophytes and in plants as a whole. There are quinoa ecotypes adapted to valley, highland, salt desert, sea level and tropical environments, displaying broad genetic variability in salinity tolerance. For this reason, quinoa represents a valuable resource for selection of the most suitable material and for breeding new varieties adapted to different environmental and geographical conditions. In this chapter, scientific studies on salinity tolerance in quinoa conducted in the last decade by numerous research groups operating in at least nine different countries are described. We focus on studies in which different quinoa genotypes are compared for their response to saline conditions, demonstrating that salt tolerance is a complex, multigenic trait involving a plethora of physiological and structural adaptations. Results available to date regarding the effect of salinity on the nutritional properties of quinoa are reported.

La salinidad está hoy entre las restricciones más extendidas en la agricultura de regadío. Así, la tolerancia a la sal es un rasgo agronómicamente importante que está recibiendo cada vez más atención entre los científicos de todo el mundo. La quinua es tolerante a la salinidad del suelo y otros factores ambientales adversos, y por consiguiente atrae la atención de los investigadores como un cultivo posible en un escenario mundial cambiante en el que la escasez de los recursos hídricos y el aumento de la salinización del suelo y el agua son las principales causas de la pérdida de cultivos. La tolerancia excepcional de la quinua a la salinidad, heladas, sequías y otros tipos de estrés abiótico también hace que sea una especie modelo para la investigación de los mecanismos celulares, fisiológicos, biomoleculares y morfológicas en la base de la tolerancia al estrés en halófitas y en las plantas en su conjunto. Hay ecotipos de quinua adaptadas al valle, altiplano, salares, el nivel del mar y los trópicos, que muestran una amplia variabilidad genética de la tolerancia a la salinidad. Por esta razón, la quinua representa un recurso valioso para la selección del material más adecuado para la obtención de nuevas variedades adaptadas a diferentes condiciones ambientales y geográficas. En este capítulo, se describen los estudios científicos sobre la tolerancia a la salinidad en la quinua realizados en la última década por numerosos grupos de investigación que operan en al menos nueve países diferentes. Nos centramos en los estudios en los que se comparan diferentes genotipos de quinua por su respuesta a condiciones de salinidad, lo que demuestra que la tolerancia a la sal es un rasgo complejo y multigénico que implica una gran cantidad de adaptaciones fisiológicas y estructurales. Se reportan los resultados disponibles hasta ahora sobre el efecto de la salinidad sobre las propiedades nutricionales de la quinua.

Un creciente número de estudios se han realizado en los últimos años en Italia en la quinua (Chenopodium quinoa Willd). El interés en este pseudo-cereal Andino se debe principalmente a su resistencia a estreses abióticos, en particular, la sequía y la salinidad, que afectan a los ecosistemas agrícolas mediterráneos, y al alto valor nutricional de sus semillas. Las principales actividades de investigación en Italia se centran actualmente en los aspectos agronómicos, biológicos y nutricionales de la quinua. Varias pruebas de campo se han llevado a cabo en el CNR-ISAFoM de Ercolano (NA) para evaluar, en términos de crecimiento, rendimiento y aspectos fisiológicos, la capacidad de adaptación de la quinua a las condiciones edafoclimáticas italianos, y la respuesta del cultivo a diferentes prácticas de manejo agronómico. También se realizaron análisis químicos postcosecha y tecnológicos para evaluar la calidad de la semilla y la aptitud para el procesamiento de alimentos. La tolerancia de la Quinua a estrés por salinidad fue investigado bajo condiciones ambientales controladas en la Universidad de Bolonia, donde se analizaron algunas de las respuestas morfológicas y metabólicas. Todos estos estudios se llevaron a cabo dentro de los proyectos de investigación nacionales e internacionales con la colaboración de centros de investigación extranjeros (por ejemplo, CEAZA, Chile) y universidades (por ejemplo, de la Universidad de Copenhague), utilizando principalmente material vegetal seleccionado en Dinamarca o se originó en la región andina. En este capítulo, los resultados de las principales actividades de investigación llevadas a cabo en la última década por las instituciones italianas se describirán, y las perspectivas para la introducción del cultivo de la quinua en los sistemas de cultivo italianos discutidos.

La adaptación de quinua en Mali, África del Oeste, se probó dada la similitud de las condiciones agroclimáticas estresantes con el centro-norte de Chile. Las variedades campesinas usadas fueron en su mayoría de Chile (A64, BO25, BO78, PRP, PRJ, UDeC9, R49, VI-1, Regalona, Mix) más dos cultivares de cosechas Argentinas (Roja Tastina y Sajama, variedad Boliviana) y uno más proveniente de Bolivia. Los ensayos comenzaron en el 2007 y se han extendido hasta el presente. Se probaron siembras en temporada de lluvias (junio a octubre) y en temporada seca (noviembre a marzo). Se evaluaron plagas, enfermedades y rendimientos considerando las condiciones ecológicas de almacenamiento de granos y manejos más sustentables del suelo (compost). Algunos cultivares altiplánicos resultaron recalcitrantes (A64, R49 y MIX) mientras que se tuvo rendimientos más aceptables (1-2 Ton/ ha) para las variedades campesinas del centro-sur de Chile. Las semillas deben idealmente sembrarse cada estación para evitar degradación de su vigor a la germinación por la humedad ambiental y altas temperaturas debido a condiciones naturales para la conservación in situ en zonas tropicales. El ciclo de cultivo puede ser desde 90-100 días para las accesiones de Chile, hasta 108-119 días para las accesiones de Argentina. Las panojas pueden ser atacadas por hongos que deciman la producción en la estación de lluvias. Se nota también la presencia de insectos fitófagos que pertenecen a los géneros Bemisia, Aphis, y Aspavia, mientras que Coccinélidos depredan sobre éstos, como control biológico. La quinua mejoraría la oferta proteica de alta calidad en África. Posibles plagas en temporadas húmedas, ataques de insectos son tal vez controlables con manejos ecológicos, usando saponinas de las mismas quinuas. Limitante será la energía para usar aguas no fácilmente disponibles en la estación seca y para el desaponficado mecánico. El uso y aceptación por la población puede estimarse alto dada la experiencia de introducción de otros cultivos de América (papas, maíz, tomates) en este continente y la similitud culinaria con el mijo y el arroz.

La adaptación de quínoa en Mali, África del Oeste, se probó dada la similitud de las condiciones agroclimáticas estresantes con el centro-norte de Chile. Las variedades campesinas usadas fueron en mayoría de Chile (A64, BO25, BO78, PRP, PRJ, UDeC9, R49, VI-1, Regalona, Mix) más dos cultivares de cosechas Argentinas (Roja Tastina y Sajama, variedad Boliviana) y uno más proveniente de Bolivia. Los ensayos comenzaron en el 2007 y se han extendido hasta el presente. Se probaron siembras en temporada de lluvias (junio a octubre) y en temporada seca (noviembre a marzo). Se evaluaron plagas, enfermedades y rendimientos considerando las condiciones ecológicas de almacenamiento de granos y manejos más sustentables del suelo (compost). Los resultados indican que algunos cultivares altiplánicos resultaron recalcitrantes (A64, R49 y MIX) mientras se tuvo rendimientos más aceptables (1-2 Ton/ha) para las variedades campesinas del centro-sur de Chile. Las semillas deben idealmente sembrarse cada estación para evitar degradación de su vigor a la germinación por la humedad ambiental y altas temperaturas debido a condiciones naturales para la conservación in situ en zonas tropicales. El ciclo de cultivo puede ser de 90-100 días para las accesiones de Chile, a 108-119 días para las accesiones de Argentina. Las panojas pueden ser atacadas por hongos que deciman la producción en la estación de lluvias. Se nota también la presencia de insectos fitófagos que pertenecen a los géneros Bemisia, Aphis, y Aspavia, mientras que Coccinélidos depredan sobre éstos, como control biológico. El potencial de mejorar con el uso de la quínoa la oferta proteica y de un alimento de alta calidad en África es alto. Posibles plagas en temporadas húmedas, ataques de insectos son tal vez controlables con manejos ecológicos, usando saponinas de las mismas quínoas. Limitante será la energía para usar aguas no fácilmente disponibles en la estación seca y para el desaponficado mecánico. El uso y aceptación por la población puede estimarse alto dada la experiencia de introducción de otros cultivos de América (papas, maíz, tomates) en este continente. (Texte intégral)

In the present study, the effects of epibrassinolide (EBL) on indole-3-acetic acid (IAA), abscisic acid (ABA) and polyamine (PA) tissue concentrations and antioxidant potential of 7-day-old Raphanus sativus L. cv. 'Pusa chetki' seedlings grown under Cu stress were investigated. EBL treatment alone or in combination with Cu enhanced free and bound IAA titers when compared with the metal alone. Modest increases in free and bound ABA contents were observed for EBL treatment alone. However, the combination of EBL with Cu caused major increases in both forms of ABA, over Cu alone. Among the PAs analyzed, only putrescine and cadaverine concentrations were enhanced by EBL treatment alone. By contrast, a significant decline in putrescine and spermine contents was found in seedlings treated with EBL plus Cu. EBL treatments alone or in combination with Cu enhanced activities of guaiacol peroxidase (EC1.11.1.7), catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) and protein contents in comparison with metal and control treatments. A major decrease in malondialdehyde content was also recorded for EBL treatments with or without Cu. An increase in phytochelatin content was also observed in seedlings treated with EBL alone or in combination with Cu. Major improvement in radical scavenging activities, as attested by the antioxidant activity assay using DPPH (1,1-diphenylpicrylhydrazyl), and elevated deoxyribose and reducing powers, along with increased contents of ascorbic acid, total phenols and proline, also suggest a major influence of EBL application in mitigating copper-induced oxidative stress in radish seedlings.

An in-vitro model system of micropropagated shoots of the commercial clone ‘Villafranca’ of Populus alba (L.) was used to investigate polyamine (PA) biosynthesis and accumulation in response to high concentrations of zinc (Zn) and copper (Cu). Based on leaf symptoms, rate of adventitious root formation and ethylene production, 0.5-1 mM Zn was transiently toxic while 2–4 mM Zn concentrations were increasingly toxic. Free and conjugated putrescine and spermidine accumulated in a dose-response manner and proportionally to toxicity. The expression profiles of the PA biosynthetic genes were analyzed by RT-PCR in plants exposed to Zn. In both leaves and stems, PaADC and PaODC transcript levels were early enhanced by all Zn concentrations, while those of PaSAMDC did not. In adventitious roots, free and conjugated PA levels also rose, although their composition and reciprocal ratios were different from those of leaves and no changes in transcript levels of PA biosynthetic genes were detected. Several Cu concentrations (5-500 μM) were tested in shoots showing severe leaf toxicity, strongly impaired adventitious root formation and high ethylene production. No changes in PA levels were detected until culture end. The different timing of the PA response to Zn and Cu, despite their rapid uptake and translocation already at 24 h, is discussed in relation to the extent of leaf toxicity.

Poplar is a good candidate for use in phytoremediation of contaminated soil, but its tolerance to heavy metals has not been fully investigated yet. In the present work, an in-vitro model system with shoot cultures was used to investigate the tolerance to high concentrations of zinc (Zn) of a commercial clone (Villafranca) of Populus alba. Based on chlorophyll content (leaf chlorosis) and the rate of adventitious root formation from shoot cuttings as parameters of damage, 0.5 – 4 mM zinc concentrations were all toxic albeit to different extents. Northern blot and reverse transcriptase (RT)-PCR analyses were used to examine the expression profiles of type 1, 2 and 3 PaMT genes in stems, leaves and roots of plants exposed to Zn treatments. In leaves, MT1 and MT3 mRNA levels were enhanced by Zn, while MT2 transcripts were not affected. The PaMT expression profiles were differentially affected by Zn in an organ-specific manner, and the relationship with Zn concentration and exposure time was rarely linear. The developmental and molecular data reveal that the in vitro model is a sensitive and reliable system to study heavy metal stress responses.

Le piante del genere Passiflora, originarie delle zone tropicali e sub-tropicali del Centro- e Sud America, comprendono diverse centinaia di specie. Alcune di queste sono coltivate come piante da frutto, altre, come ad es. Passiflora incarnata L., sono note da tempo per le loro proprietà sedative e farmacologiche e per questo sono state studiate in modo approfondito per quanto riguarda la composizione chimica e le attività biologiche. I principali composti bioattivi descritti nelle piante appartenenti a questo genere sono rappresentati da derivati glicosidici dei flavonoidi luteolina e agipenina, quali orientina, isoorientina, vitexina, isovitexina, shaftoside e isoshaftoside [1]. Le tecniche delle colture di cellule vegetali rappresentano uno strumento utile per studiare la produzione e l’accumulo di costituenti attivi. Le colture in vitro presentano alcuni vantaggi rispetto alla pianta intera per gli studi di biosintesi, in particolare sono relativamente semplici da coltivare e possono essere mantenute in condizioni nutritive e ambientali strettamente controllate. Inoltre, la produzione di composti del metabolismo secondario può essere modulata ottimizzando alcuni fattori fisico-chimici che svolgono un ruolo importante nella sintesi di tali composti. In particolare l’elicitazione con fattori biotici o abiotici rappresenta una delle strategie più utilizzate per incrementare la produzione di alcuni metaboliti che vengono scarsamente prodotti oppure per indurre la sintesi di altri che normalmente non vengono sintetizzati [2]. Scopo di questo lavoro è di valutare la capacità di produzione di alcuni glicosil-flavonoidi (isoorientina, orientina, isovitexina e vitexina) in colture in vitro ottenute da due specie di Passiflora e di analizzare la risposta di tali colture al trattamento con elicitori quali il metilgiasmonato (MJ) e la luce UV-B. Le colture in vitro di P. quadrangularis producono livelli molto bassi di flavonoidi. Tra quelli testati sono presenti solo orientina ed isorientina. Il trattamento con luce UV-B determina un incremento fino ad oltre 100 volte nei livelli di questi flavonoidi e un’induzione di isovitexina e vitexina, e tale aumento risulta strettamente dipendente dalla dose e dalla durata dell’irraggiamento. Anche l’elicitazione con MJ provoca un aumento nella produzione di flavonoidi nelle colture di P. quadrangularis, seppure di entità inferiore rispetto a quello indotto dalla luce UV-B. Le colture di callo di P. quadrangularis trattate con la dose UV-B in grado di stimolare maggiormente la produzione di flavonoidi mostrano un aumento dell’attività antiossidante. Anche l’enzima fenilalanina ammonio-liasi (PAL) risulta regolato dal trattamento con luce UV-B. La risposta delle colture in vitro di P. palmeri all’elicitazione con luce UV è più attenuata rispetto all’altra specie e addirittura assente nel caso del MJ. I risultati confermano l’inducibilità della biosintesi di flavonoidi da parte della luce UV-B e, in misura minore, del MJ in colture di callo di P. quadrangularis. Le differenze riscontrate nella risposta all’elicitazione tra le due specie prese in esame suggeriscono meccanismi specie-specifici nell’attivazione delle vie biosintetiche e/o di trasmissione del segnale in risposta ad uno stimolo.

Effetti di zinco e rame sull’espressione genica delle metallotioneine e sul contenuto di poliammine in Populus alba L. in micropropagazione S. BIONDI1, C. FRANCHIN1, T. FOSSATI2, E. PASQUINI1, V. ZIOSI1, P. TORRIGIANI1, S. CASTIGLIONE2, 1 Dipartimento di Biologia, Università di Bologna, Via Irnerio 42, 40126 Bologna; 2 Dipartimento di Biologia, Università di Milano, via Celoria 26, 20133 Milano Vi sono molte evidenze a favore di un possibile coinvolgimento delle metallotioneine (MT) nelle risposte a stimoli ambientali, in particolare si ipotizza che queste proteine siano strettamente correlate alla capacità di molti organismi di tollerare dosi elevate di metalli pesanti. Nelle piante le MT sono classificate in quattro classi (COBBETT, GOLDSBROUGH, 2002)) e in Arabidopsis, pomodoro e cotone vi sono famiglie geniche di MT (ZHOU & GOLDSBROUGH, 1994; GIRITCH et al., 1998; HUDSPETH et al., 1996). Per chiarire le funzioni delle MT nelle piante, sono stati effettuati numerosi studi sull’espressione di questi geni sia durante lo sviluppo che in risposta a stress biotico e abiotico con risultati ancora contrastanti. Pertanto informazioni certe sull’attività endogena delle MT non sono ancora state raggiunte e il loro ruolo rimane elusivo. Nei vegetali le poliammine (PA) si accumulano in risposta a vari stimoli biotici e abiotici (BOUCHEREAU et al., 1999), compresi gli inquinanti ambientali quali i metalli pesanti (WEINSTEIN et al., 1986; HAUSCHILD, 1993). Esse svolgono probabilmente un ruolo nella resistenza allo stress ossidativo, stabilizzando gli acidi nucleici e le membrane biologiche. Il rapido accrescimento, l’elevata produzione di biomassa, l’apparato radicale esteso, la facile propagazione vegetativa e la possiblità di utilizzo nelle coltivazioni a breve rotazione fanno del pioppo un ottimo candidato come pianta arborea da usare nel fitorisanamento di siti inquinati. Tuttavia, sono molte scarse le informazioni circa le sue capacità di accumulo e di tolleranza nei confronti dei metalli. Inoltre, il pioppo è di recente assurto a “pianta arborea modello” in quanto il suo genoma è stato interamente sequenziato, aprendo la via a studi molecolari di ampio respiro (TUSKAN et al., 2004). Nel presente lavoro, è stata esaminata la risposta di un clone commerciale di Populus alba, la cv Villafranca, allevato in vitro attraverso la micropropagazione ed esposto per tempi diversi, fino a un massimo di 15 giorni, a dosi elevate di ZnSO4 o CuCl2. Sono stati valutati i sintomi visivi di tossicità, i livelli endogeni di poliammine libere e coniugate, e i livelli di trascritto di tre geni codificanti MT (MT1, MT2 e MT3). I risultati hanno evidenziato un’evidente clorosi fogliare già dopo 1 giorno in piante esposte a concentrazioni di Zn di 1, 2 e 4 mM, ma non 0.5 mM. Un forte ingiallimento e senescenza delle foglie si osservava soltanto con le due dosi più alte a partire dal 7° giorno. Tali sintomi di tossicità, associati a un calo significativo nel contenuto di clorofille, si palesavano in piante trattate con Cu anche a concentrazioni molto più basse (0.1 mM). La formazione di radici avventizie sui germogli trattati con Zn era inibita in maniera dose dipendente, arrivando fino al 50%. Al contrario, in presenza di Cu la rizogenesi era totalmente inibita a partire dalla concentrazione 0,1 mM e fortemente ridotta anche a dosi molto più basse (5 mM). Pur essendo già noto l’effetto fortemente inibente del Cu sulla crescita radicale (MURPHY & TAIZ, 1995) i dati mostrano che anche la rizogenesi è molto sensibile alla tossicità di questo metallo. Del resto, il Cu è uno dei metalli più tossici conosciuti. Nel suolo, la sua biodisponibilità è bassa, ma in soluzione acquosa la sua tossicità viene messa in evidenza provocando stress ossidativo (FERNANDES & HENRIQUES, 1991). Come riportato in Figura 1, il contenuto totale di PA, sia libere che coniugate, misurate dopo 15 giorni di esposizione a tre diverse concentrazioni di Zn (0,5, 1 e 2 mM) ...

I giasmonati (JA) costituiscono un segnale importante nell’elicitazione di risposte a stress mediante induzione di JA-induced proteins (JIPs); tra queste, gli enzimi biosintetici delle poliammine. E’ stato riportato un ruolo attivo dei JA anche nei processi di sviluppo, quali la crescita e la maturazione dei frutti, e in post-raccolta. In polpa di mela e ciliegia i livelli di JA mostrano un picco di concentrazione durante le fasi precoci di crescita (divisione cellulare); in mela tali livelli salgono nuovamente all’inizio del climaterio etilenico. Dati esogenamente questi composti inducono una serie di risposte biologiche: stimolano la produzione di beta-carotene in pomodoro, riducono il danno da freddo in post-raccolta in mango, riducono la muffa verde in pompelmo e promuovono lo sverdimento in mela. Tuttavia, le relazioni reciproche tra JA ed etilene non sono ben stabilite. In mela il metilgiasmonato (MJ) stimola la produzione di etilene in frutti pre-climaterici e la inibisce in quelli post-climaterici. Alcuni Autori suggeriscono che l’effetto del MJ sullo sverdimento della mela sia almeno in parte indipendente dall’etilene. Risultati contraddittori sono stati ottenuti anche in altri sistemi modello. Una relazione ben stabilita è quella tra JA e poliammine. I JA infatti stimolano fortemente il metabolismo delle poliammine con forti riflessi sui loro coniugati fenolici. I livelli di poliammine, che sono importanti regolatori della crescita, variano durante lo sviluppo del frutto e il trattamento del frutto in maturazione con poliammine libere riduce l’emissione di etilene e il rammollimento della polpa. Questo lavoro riporta i risultati di un’indagine atta a stabilire quali siano le relazioni reciproche tra JA ed etilene allo scopo di chiarire i meccanismi fisiologici coinvolti nel controllo della maturazione e della post-raccolta nelle nettarine. A seguito della somministrazione esogena di JA in campo (MJ e propilgiasmonato, PJ) al frutto in S3, l’emissione di etilene al climaterio, così come l’evoluzione dei principali parametri di qualità del frutto, viene inibita da PJ ma non da MJ. L’espressione di ACO1 è influenzata solo da MJ. I livelli di poliammine libere sono significativamente incrementati sia nell’esocarpo che nel mesocarpo da entrambi i trattamenti. L’espressione dell’enzima che decarbossila l’S-adenosilmetionina (SAM), precursore comune dell’etilene e delle poliammine, non è influenzata dai trattamenti. L’inibizione dell’emissione di etilene e il rallentamento della maturazione che ne consegue sono associati ad incrementi nel contenuto di poliammine che potrebbero contribuire all’effetto antisenescente dei trattamenti. Si conferma così il ruolo dei JA nel controllo della maturazione del frutto e il coinvolgimento delle poliammine in tale processo.

Saponins (SAPs) are a diverse family of plant secondary metabolites and due to their biological activities, SAPs can be utilised as biopesticides and as therapeutic compounds. Given their widespread industrial use, a search for alternative sources of SAPs is a priority. Quinoa ( Chenopodium quinoa Willd) is a valuable food source that is gaining importance worldwide for its nutritional and nutraceutical properties. SAPs from quinoa seed coats could represent a new sustainable source to obtain these compounds in high quantities due to the increasing production and worldwide expansion of the crop. This research aims to characterise saponins of seed coat waste products from six different quinoa varieties for their potential use as a saponin source. Gas chromatography (GC)- and Liquid chromatography (LC)- with mass spectrometry (MS) were applied for qualitative and relative quantitative analysis of saponins. GC–MS led to the identification of three main aglycones, oleanolic acid (Ole), hederagenin (Hed), and a phytolaccagenic acid (Phy), while LC–MS enabled characterization of 24 SAPs with varying sugar moieties. Hed was the most abundant aglycone, followed by Phy and Oledepending on the genotype. Saponin distribution and relative abundances are discussed in the light of genotype provenance and agronomic features. Improved knowledge on the phytochemicals present in quinoa varieties might help in finding valuable and sustainable uses for quinoa SAPs in agroindustry as biopesticides as well as in the production of food and pharmaceuticals.

To further our understanding of the mechanisms governing salt stress responses and adaptation in halophytes, we explored morphological, metabolic, and gene expression responses to high salinity in quinoa (Chenopodium quinoa Willd). The main objective of this study was to analyze selected responsive genes in a time-course experiment to test for expression kinetics and to compare short-term salt-induced effects at the transcript level between two Chilean landraces belonging to different ecotypes. Quinoa genotypes exhibit a large variability in their responses to salinity, but it is not clear whether this is strictly related to the ecotype to which they belong. We tested this hypothesis by comparing the expression levels of genes involved in growth, ion homeostasis, abscisic acid (ABA) biosynthesis, perception, and conjugate cleavage, polyamine (PA) biosynthesis and oxidation, and proline biosynthesis as well as genes encoding ABA-dependent and −independent transcription factors. Landraces R49 (salares ecotype) and Villarrica (VR, coastal-lowlands ecotype) were analyzed from 0.5 to 120Âh after transfer to saline (300ÂmM NaCl) or non-saline (control) medium. All the genes, except CqSOS1 and CqNHX, were investigated here for the first time in quinoa under salt stress. Transcript levels were determined by quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) analysis. Germination, seedling growth, ABA, and PA contents were evaluated in parallel. Even though on saline medium germination was inhibited in VR but not in R49, seedling growth reduction at 120Âh was not substantially different in the two landraces. The ABA biosynthetic enzyme NCED was the most strongly salt-induced gene; ABA content was similarly enhanced (shoots) or unaffected (roots) in both R49 and VR. NaCl treatment also altered transcript levels of some PA metabolic enzymes and the PA profile leading to an enhanced ratio between the higher PAs and putrescine. All other genes also exhibited similar expression profiles in response to salinity in the two landraces especially in roots, while in shoots some differences were observed. Our results provide new information indicating that crucial salt adaptation strategies at the molecular level and in terms of ABA and PA contents are shared by the coastal-lowlands and salares landraces; however, the timing of the onset of transcriptional changes (e.g., NCED, ABF3, and RD22) may reflect genotype-dependent constitutive and/or inducible adaptive strategies.

Quinoa (Chenopodium quinoa Willd) is an ancient Andean seed-producing crop well known for its exceptional nutritional properties and resistance to adverse environmental conditions, such as salinity and drought. Seed storage proteins, amino acid composition, and bioactive compounds play a crucial role in determining the nutritional value of quinoa. Seeds harvested from three Chilean landraces of quinoa, one belonging to the salares ecotype (R49) and two to the coastal-lowlands ecotype, VI-1 and Villarrica (VR), exposed to two levels of salinity (100 and 300 mM NaCl) were used to conduct a sequential extraction of storage proteins in order to obtain fractions enriched in albumins/globulins, 11S globulin and in prolamin-like proteins. The composition of the resulting protein fractions was analyzed by one- and two-dimensional polyacrylamide gel electrophoresis. Results confirmed a high polymorphism in seed storage proteins; the two most representative genotype-specific bands of the albumin/globulin fraction were the 30- and 32-kDa bands, while the 11S globulin showed genotype-specific polymorphism for the 40- and 42-kDa bands. Spot analysis by mass spectrometry followed by in silico analyses were conducted to identify the proteins whose expression changed most significantly in response to salinity in VR. Proteins belonging to several functional categories (i.e., stress protein, metabolism, and storage) were affected by salinity. Other nutritional and functional properties, namely amino acid profiles, total polyphenol (TPC) and flavonoid (TFC) contents, and antioxidant activity (AA) of protein extracts were also analyzed. With the exception of Ala and Met in R49, all amino acids derived from protein hydrolysis were diminished in seeds from salt-treated plants, especially in landrace VI-1. By contrast, several free amino acids were unchanged or increased by salinity in R49 as compared with VR and VI-1, suggesting a greater tolerance in the salares landrace. VR had the highest TPC and AA under non-saline conditions. Salinity increased TPC in all three landraces, with the strongest increase occurring in R49, and enhanced radical scavenging capacity in R49 and VR. Overall, results show that salinity deeply altered the seed proteome and amino acid profiles and, in general, increased the concentration of bioactive molecules and AA of protein extracts in a genotype-dependent manner.

none 5 no This research was supported by funds from the University of Bologna (RFO2014) to S.B.and from the University of Urbino (RFO 2014) to V.S.. Quinoa (Chenopodium quinoa Willd), an ancient Andean seed crop, exhibits exceptional nutritional properties and resistance to abiotic stress. The species' tolerance to heavy metals has, however, not yet been investigated nor its ability to take up and translocate chromium (Cr). This study aimed to investigate the metabolic adjustments occurring upon exposure of quinoa to several concentrations (0.01–5mM) of CrCl3. Young hydroponically grown plants were used to evaluate Cr uptake, growth, oxidative stress, and other biochemical parameters three and/or seven days after treatment. Leaves accumulated the lowest amounts of Cr, while roots and stems accumulated the most at low and at high metal concentrations, respectively. Fresh weight and photosynthetic pigments were reduced only by the higher Cr(III) doses. Substantially increased lipid peroxidation, hydrogen peroxide, and proline levels were observed only with 5mM Cr(III). Except for a significant decrease at day 7 with 5mM Cr(III), total polyphenols and flavonoids maintained control levels in Cr(III)-treated plants, whereas antioxidant activity increased in a dose-dependent manner. Maximum polyamine accumulation was observed in 1mM CrCl3-treated plants. Even though α- and γ-tocopherols also showed enhanced levels only with the 1mM concentration, tyrosine aminotransferase (TAT, EC 2.6.1.5) activity increased under Cr(III) treatment in a dose- and time-dependent manner. Taken together, results suggest that polyamines, tocopherols, and TAT activity could contribute to tolerance to 1mM Cr(III), but not to the highest concentration that, instead, generated oxidative stress. open Scoccianti, Valeria; Bucchini, Anahi E.; Iacobucci, Marta; Ruiz, Karina B.; Biondi, Stefania Scoccianti, Valeria; Bucchini, Anahi E.; Iacobucci, Marta; Ruiz, Karina B.; Biondi, Stefania

Quinoa (Chenopodium quinoa Willd.) is a highly salt-tolerant species subdivided into five ecotypes and exhibiting broad intra-specific differences in tolerance levels. In a greenhouse study, Chilean landraces belonging either to the salares (R49) or coastal lowlands (VI-1, Villarrica) ecotype with contrasting agro-ecological origins were investigated for their responses to high salinity. The effects of two levels of salinity, 100 (T1) and 300 (T2) mM NaCl, on plant growth and on some physiological parameters were measured. Leaf and root Na(+) accumulation differed among landraces. T2 reduced growth and seed yield in all landraces with maximum inhibition relative to controls in R49. Salinity negatively affected chlorophyll and total polyphenol content (TPC) in VI-1 and Villarrica but not R49. Germination on saline or control media of seeds harvested from plants treated or not with NaCl was sometimes different; the best performing landrace was R49 insofar as 45-65% of seeds germinated on 500 mM NaCl-containing medium. In all landraces, average seedling root length declined strongly with increasing NaCl concentration, but roots of R49 were significantly longer than those of VI-1 and Villarrica up to 300 mM NaCl. Salt caused increases in seed TPC relative to controls, but radical scavenging capacity was higher only in seeds from T2 plants of R49. Total SDS-extractable seed proteins were resolved into distinct bands (10-70 kDa) with some evident differences between landraces. Salt-induced changes in protein patterns were landrace-specific. The responses to salinity of the salares landrace are discussed in relation to its better adaptation to an extreme environment.

Neochloris oleoabundans (Chlorophyta) is widely considered one of the most promising microalgae for biotechnological applications. However, the large-scale production of microalgae requires large amounts of water. In this perspective, the possibility of using exhausted growth media for the re-cultivation of N. oleoabundans was investigated in order to simultaneously make the cultivation more economically feasible and environmentally sustainable. Experiments were performed by testing the following media: autotrophic exhausted medium (E+) and mixotrophic exhausted medium after cultivation with glucose (EG+) of N. oleoabundans cells grown in a 20-L photobioreactor (PBR). Both exhausted media were replenished with the same amounts of nitrate and phosphate as the control brackish medium (C). Growth kinetics, nitrate and phosphate consumption, photosynthetic pigments content, photosynthetic efficiency, cell morphology, and lipid production were evaluated. Moreover, the free fatty acid (FFA) composition of exhausted media and the polyamine (PA) concentrations of both algae and media were analyzed in order to test if some molecules, released into the medium, could influence algal growth and metabolism. Results showed that N. oleoabundans can efficiently grow in both exhausted media, if appropriately replenished with the main nutrients (E+ and EG+), especially in E+ and to the same extent as in C medium. Growth promotion of N. oleoabundans was attributed to PAs and alteration of the photosynthetic apparatus to FFAs. Taken together, results show that recycling growth medium is a suitable solution to obtain good N. oleoabundans biomass concentrations, while providing a more sustainable ecological impact on water resources.