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The multinational Arabidopsis research community is highly collaborative and over the past thirty years these activities have been documented by the Multinational Arabidopsis Steering Committee (MASC). Here, we (a) highlight recent research advances made with the reference plantArabidopsis thaliana; (b) provide summaries from recent reports submitted by MASC subcommittees, projects and resources associated with MASC and from MASC country representatives; and (c) initiate a call for ideas and foci for the "fourth decadal roadmap," which will advise and coordinate the global activities of the Arabidopsis research community., UKRI-BBSRC grant [BB/M004376/1]; HHMI Faculty Scholar Fellowship; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [118Z137], UKRI-BBSRC grant, Grant/Award Number: BB/M004376/1; HHMI Faculty Scholar Fellowship; the Scientific and Technological Research Council of Turkey, Grant/Award Number: 118Z137

Nell’ambito dell’orticoltura, così come in generale in tutte le produzioni agrarie, la propagazione riveste un ruolo prioritario. Il suo scopo, infatti, è quello di fornire materiale vegetale per l’impianto delle colture: semi; piantine da seme (semenzali); organi sotterranei (tuberi, rizomi, bulbi); piante autoradicate (moltiplicazione per talea, margotta, propaggine); piante innestate; piante micro-propagate (da colture in vitro). Nel capitolo vengono approfondite tutte queste modalità di propagazione con approfondimenti su alcuni casi studio (carciofo, fragola, patata)

In autogamous plants, self-pollination is ensured by a timely opening of anthers (dehiscence) and release of mature pollen grains. Auxin plays a paramount role in controlling the correct timing of anther dehiscence. Now, a molecular switch that allows the timely change in auxin level in rice anthers has been unveiled.

Grafting of vegetable is a unique horticultural technology practiced for many years in East Asia to overcome issues associated with intensive cultivation using limited arable land. This technology was introduced to Europe and other countries in the late 20th century along with improved grafting methods suitable for commercial production of grafted vegetable. Later, grafting was introduced to North America from Europe and it is now attracting growing interest worldwide, both from greenhouse and open field growers. Vegetable crops are often exposed to abiotic stresses in the root zone (e.g. salinity, drought, alkalinity and heavy metals contamination) limiting crop productivity in many parts of the world. One way to avoid or reduce losses in production caused by adverse soil chemical conditions in vegetables crops in particular Solanaceous crops (tomato, eggplant, and pepper) and Cucurbits (watermelon, melon and cucumber) would be to graft them onto rootstocks capable of reducing the effect of external stresses on the shoot. This review gives an actual overview how grafting can alleviate the adverse effects of the main abiotic stresses on vegetable’s crop performance at agronomical level. The paper will also focus on the additional improvement of abiotic stresses tolerance through integration of vegetable grafting with other control strategies such as inoculation with arbuscular mycorrhizal fungi and fertilization.

Arabidopsis abcb1 abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcb1 and abcb19 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcb1 but not in the abcb19 mutant. Accordingly, endothecium lignification is altered only in abcb1 anthers. Both abcb1 and abcb1 abcb19 stamens also show altered early development, with asynchronous anther locules and a multilayer tapetum. DAPI staining showed that the timing of meiosis is asynchronous in abcb1 abcb19 anther locules, while only a small percentage of pollen grains are nonviable according to Alexander's staining. In agreement, TAM (TARDY ASYNCHRONOUS MEIOSIS), as well as BAM2 (BARELY ANY MERISTEM)--involved in tapetal cell development--are overexpressed in abcb1 abcb19 young flower buds. Correspondingly, ABCB1 and ABCB19 mRNA localization supports the observed phenotypes of abcb1 and abcb1 abcb19 mutant anthers. In conclusion, we provide evidence that auxin transport plays a significant role both in early and late stamen development: ABCB1 plays a major role during anther development, while ABCB19 has a synergistic role.

Arabidopsis abcb1 abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcb1 and abcb19 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcb1 but not in the abcb19 mutant. Accordingly, endothecium lignification is altered only in abcb1 anthers. Both abcb1 and abcb1 abcb19 stamens also show altered early development, with asynchronous anther locules and a multilayer tapetum. DAPI staining showed that the timing of meiosis is asynchronous in abcb1 abcb19 anther locules, while only a small percentage of pollen grains are non-viable according to Alexander's staining. In agreement, TAM (TARDY ASYNCHRONOUS MEIOSIS), as well as BAM2 (BARELY ANY MERISTEM)-involved in tapetal cell development-are overexpressed in abcb1 abcb19 young flower buds. Correspondingly, ABCB1 and ABCB19 mRNA localization supports the observed phenotypes of abcb1 and abcb1 abcb19 mutant anthers. In conclusion, we provide evidence that auxin transport plays a significant role both in early and late stamen development: ABCB1 plays a major role during anther development, while ABCB19 has a synergistic role.

Phytochelatins (PCs) are metal binding peptides involved in heavy metal detoxification. To assess whether enhanced phytochelatin synthesis would increase heavy metal tolerance and accumulation in plants, we overexpressed the Arabidopsis phytochelatin synthase gene (AtPCS1) in the non-accumulator plant Nicotiana tabacum. Wild-type plants and plants harbouring the Agrobacterium rhizogenes rolB oncogene were transformed with a 35S AtPCS1 construct. Root cultures from rolB plants could be easily established and we demonstrated here that they represent a reliable system to study heavy metal tolerance. Cd2+ tolerance in cultured rolB roots was increased as a result of overexpression of AtPCS1, and further enhanced when reduced glutathione (GSH, the substrate of PCS1) was added to the culture medium. Accordingly, HPLC analysis showed that total PC production in PCS1-overexpressing rolB roots was higher than in rolB roots in the presence of GSH. Overexpression of AtPCS1 in whole seedlings led to a twofold increase in Cd2+ accumulation in the roots and shoots of both rolB and wild-type seedlings. Similarly, a significant increase in Cd2+ accumulation linked to a higher production of PCs in both roots and shoots was observed in adult plants. However, the percentage of Cd2+ translocated to the shoots of seedlings and adult overexpressing plants was unaffected. We conclude that the increase in Cd2+ tolerance and accumulation of PCS1 overexpressing plants is directly related to the availability of GSH, while overexpression of phytochelatin synthase does not enhance long distance root-to-shoot Cd2+ transport.

The objective of the current work was to evaluate the possibility to improve the growth and quality of micropropagated shoots of Aloe barbadensis Miller through the addition of charcoal to the rooting substrate. Single shoots were multiplied in 45 days using a substrate containing agar, MS salts, sucrose 3%, BA 1 mg L-1, and IAA 0.2 mg L-1; shoots were then transferred for 20 and 40 days in a solid substrate containing half-strength MS salts, and sucrose 3% with or without the addition of charcoal at the concentration of 1%. After this period, shoots were transferred in greenhouse for acclimatization using a substrate containing peat:perlite (1:1 v/v). Growth parameters of shoots and their content of total chlorophyll and carotenoids were analyzed at the end of 20 and 40 days of in vitro culture and after 50 days of acclimatization. The height, fresh weight and root number of shoots were highest in the substrate containing charcoal after 40 days of in vitro culture. The content of total chlorophyll and carotenoids in shoots were highest without the addition of charcoal to the substrate and after 40 days of in vitro culture. The positive effects of charcoal on growth parameters of shoots persisted into the next phase of acclimatization while the content of total chlorophyll and carotenoids in shoots decreased.

Consumer interest in the quality of vegetable products has increased in recent years especially for the beneficial effects of vegetables on human health. Vegetable quality is a broad term and includes physical properties, flavor, and health–related compounds. The purpose of this paper is to review the recent literature of the main pre-harvest factors that can improve the quality of vegetables and consequently their beneficial role in human diet. The importance of genotype and grafted plants selection, the optimization of the environmental conditions (light and temperature) and the advantages and disadvantages of greenhouse in comparison to open field cultivation concerning product quality will be outlined first; followed by the optimization of agricultural practices in particular, water quantity and quality, mineral nutrition, salinity and growing system (e.g. soilless). The review will conclude by identifying several prospects for future research such as modeling of the nutritional value of vegetable crops.

Les cultures maraîchères sont souvent cultivées dans des conditions défavorables à cause des stress abiotiques (e.g. salinité, sécheresse, alcalinité) et biotiques fréquemment rencontrés en culture protégée. Les plantes exposées à ces types de stress présentent divers troubles physiologiques et biochimiques conduisant à un retard de croissance et une perte sévère du rendement. Une façon d'éviter ou de réduire les pertes de production causées par les mauvaises conditions chimiques du sol ou à cause de stress biotiques dans les cultures maraîchères serait par l’association les champignons mycorhiziens à arbuscules capable de réduire les symptômes du stress en complément des mécanismes protecteurs intrinsèques de la plante. Trois expériences de culture en pot sous serre ont été conduites afin d'étudier La réponse des plantes mycorhizées (+MA) e non (-MA) sur la croissance, le rendement et la composition minerale de trois espèce de cucurbitacées: courgette (Cucurbita pepo L., expérience 1), concombre (Cucumis sativus L., expérience 2), et melon (Cucumis melo L.). La mycorhization des plantes a été réalisée en utilisant un inoculum commercial contenant Glomus intraradices et Glomus mosseae produites par Italpollina SpA. Dans l'expérience 1 ont été cultivés en pot avec deux niveaux de salinité (1 et 35 mM de chlorure de sodium), donnant des valeurs de conductivité électrique de 1,8 et 5,0 dS m-1. Dans l'expérience 2, les plantes ont également ont été cultivés en pot et fourni avec des solutions nutritives ayant deux niveaux de pH (6.0 ou 8.1). Le pH de la solution nutritive élevée a la même composition de base plus un montant additionnel de 10 mM NaHCO3 et 0,5 g L-1 de CaCO3. Dans l’expérience 3, les plantes de melon ont été cultivées aussi en pot sans et avec inoculation de Fusarium oxysporum f.sp. melonis race 1,2w. Dans les deux premières expériences, la croissance et le rendement de la courgette et le concombre a diminué à la fois chez les plantes avec et sans mycorhization, mais l'ampleur de la diminution due à la salinité et à l’alcalinité était plus élevé chez les plantes +MA que celles –MA. Les mécanismes impliqués dans la protection des plantes mycorhizées face au stress salin et alcalin seraient liés à des teneurs plus élevées en macro (K dans l'expérience 1, et P, K et Mg dans l'expérience 2) et micro éléments (Zn expérience 1, et plus Fe, Zn, Mn dans l'expérience 2) et donc une meilleure croissance que les plantes non mycorhizées. Les résultats de l’expérience 3 ont montré une augmentation de la tolérance plants mycorhizés à Fusarium oxysporum f.sp. melonis 1.2 et donc un retard dans l’apparition de symptômes.

The expansion of hydroponics in many countries of the world in the last few decades may be ascribed to the ability of soilless growing systems to avoid various problems arising from the use of the soil. Cucumber (Cucumis sativus L.) and zucchini (Cucurbita pepo L.) plants were grown in closed-soilless culture under unheated-greenhouse conditions at the experimental farm of University of Tuscia, Central Italy to evaluate the effects of four substrates (rockwool, pumice, perlite, and cocofiber) on growth, yield and plant mineral composition. For both cultures, plants grown in cocofiber, perlite and pumice yielded more than those grown in rockwool. The better temperature regime in cocofiber, perlite and pumice was due to the greater thermal inertia compared to rockwool slabs. The concentration of N in zucchini and cucumber leaves was significantly higher in cocofiber, perlite and pumice in comparison to the rockwool treatment. The concentration of K was significantly affected by the substrate only for the zucchini squash with the highest value recorded on the organic substrate (cocofiber), whereas the Ca concentration was significantly influenced by the growing media only for cucumber with the highest value observed on pumice. Finally, the lowest Mg concentration in leaf tissue was observed on plants grown with the rockwool substrate for both zucchini squash and cucumber. We can conclude that cocofiber, perlite and pumice are suitable for zucchini and cucumber production in closed soilless system, whereas the use of rockwool is more suitable for crops grown under heated greenhouse conditions.

Consumer interest in the quality of vegetable products has increased in recent years. Regular consumption of vegetables has been linked to a reduction of some diseases, since vegetable is a source of an array of phytochemicals, which are appreciated for their benef icial heal th ef fects. Vegetable quality is a complex issue with different means depending to the target customer group. Quality has both a product- and a consumer-dependent dimension. From the first perspective, quality attributes are inherent in a product and can be objectively quantified, whereas a consumer orientation, which defines quality in terms of user satisfaction, is much less tangible and less quantifiable concept. This review will be focused only on product-oriented quality and objective criteria for its evaluation. Standard for quality assessment of fresh vegetables are established in Europe and North and Central America. However, they take into consideration mostly external quality attributes (e.g. size, shape, color, absence of defects and decay, critical concentrations of pesticides and nitrate), whereas very important internal quality attributes such as texture, flavor and healthpromot ing compounds are not considered. Environmental conditions, crop management and physiological factors may modify the vegetable quality. The purpose of this paper is to review the recent literature dealing with the main pre-harvest factors that can modify the quality of vegetables and, in particular, the physical properties, flavor, and health–related compounds. First of all, the importance of the genotype and grafted plants selection, the optimization of the environmental conditions and the advantages and disadvantages of protected environments in comparison to open field cultivation concerning product quality will be outlined. Then, the effects of the optimization of agricultural practices, in particular water quantity and quality, mineral nutrition and growing systems (e.g. soilless culture), will be discussed. The review highlighted that vegetable quality is a product of the interaction of genetic, climatic, and cultural factors. Finding the best combinations of those factors to maximize vegetable quality according consumer demand will be a challenge. The use of novel cultural practices and development of new genetic lines to enhance the quality of vegetables are the main directions that research should take in the near future. Integrated quality production and management must be considered as a global target to reach.

Les produits à base d'acides aminés ont été utilisés par les agriculteurs depuis plus de trois décennies en raison de leur nombreux effets bénéfiques sur la croissance et rendement des cultures agricoles. Les acides aminés peuvent être d'origine végétale ou animale. Les acides aminés d'origine végétale, grâce à leurs caractéristiques biochimiques, sont plus facilement absorbés par les plantes par rapport à ceux d'origine animale, Ils ont également une plus grande efficacité nutritionnelle. En outre, grâce à l'origine exclusivement végétale les engrais foliaires ne contiennent pas de résidus d'antibiotiques, ou tous autres contaminants. De nombreux résultats de recherche démontrent clairement les effets positifs de la fertilisation foliaire avec des acides aminés d'origine végétale sur les produits horticoles tels que: amélioration de l'absorption des éléments nutritifs et de l'efficience de l'utilisation des nutriments; meilleure résistance aux stress biotiques et abiotiques; et l'amélioration de la qualité du produit horticole. Deux expériences sous serre ont été conduites afin d'étudier l'efficacité d'un engrais à base d'acides aminés (TRAINER, Italpolina S.P.A) sur la croissance et le développent du mais (Zea mays L., expérience 1) et de la laitue (Lactuca sativa L., expérience 2). Dans l'expérience 1, les plantes ont été cultivés en pot avec quatre concertations du produit Trainer: 0 - 0,25 - 0.5 et 2.5 ml/L. Dans l'expérience 2, les plantes ont été cultivés dans des bacs et fourni avec deux solutions nutritives (Standard et Réduite à 10%) recevant deux concentrations du produit Trainer (0 et 2,5 ml/L). Dans la première expérience, les trois concentrations testées ont montré une croissance plus élevée de la partie aérienne (hauteur de la tige et la biomasse aérienne sèche) par rapport au témoin. En outre, l'augmentation de la concentration du produit a montré une augmentation de la teneur en chlorophylle (indice SPAD) et de la concentration de l'azote dans les feuilles indiquant le rôle bénéfique du produit dans la nutrition des plantes horticoles. Dans l'expérience 2, l'application foliaire du produit Trainer d'une façon hebdomadaire avec une concentration réduite de la solution nutritive a montré une augmentation de la production, de l'indice SPAD et de la concentration d'azote dans les feuilles de laitue par rapport aux plantes non traitées. Les résultats montrent un rôle positif de la nutrition foliaire avec Trainer dans des conditions de faible disponibilité des nutriments au niveau racinaire, indiquant que l'utilisation de ce produit peut être considéré comme un outil intéressant pour la production horticole durable.