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• MI amendment improves morphological characteristics of crop leaf. • Light-harvesting and utilization by crop is promoted after adding MI. • MI amendment upregulates crop resilience to stress. Leaf growth and function play fundamental role for crop development and production. The introduction of functional microbial strains also known as, microbial inoculants (MI) represents promising strategy for enhancing crop vigor and resilience. To obtain a comprehensive understanding of the impact of the MI technique on foliar morphology and physiological performance, a meta-analysis encompassing 168 published articles, comprising of total 1656 paired observations, was conducted. The findings showed that MI amendments resulted in notable enhancements in several key parameters. Specifically the leaf area, leaf area index, and leaf nitrogen content exhibited increases of 16.56 %, 16.28 %, and 13.76 %, respectively. Moreover, the MI-treated crops demonstrated higher values in terms of chlorophyll content, leaf gas exchange indices, and chlorophyll fluorescence parameters suggesting improvements in the MI treatment indicated that light harvesting and utilization by the crops were improved. Additionally, the linear mixed-effects model showed that changes in these parameters (except for intercellular CO 2 concentration) after MI addition had a positive effect on crop yield. Upregulated antioxidant enzyme activities, such as POD, CAT, and SOD, in crop leaves increased by 20.91 %, 12.68 %, and 23.08 %, respectively, whereas H 2 O 2 content decreased significantly, by 38.46 %. These results indicate that MI amendment is a promising strategy for improvement of light interception and utilization in crops. MI treatment is expected to increase crop tolerance to stress, thus increasing productivity and yield. Therefore, future adoption of the MI technique could contribute to ensuring food security and agricultural sustainability, however, the factors affecting MI efficacy should be further clarified. [ABSTRACT FROM AUTHOR]

• We report for the first time comprehensive evaluation of salinity tolerance in jamun (Syzygium cumini L. Skeels). • The evaluation procedure used in this work closely mimics salinity under field conditions, and may be used to evaluate the responses of other fruit crops to a prolonged, gradually increased salinity. • Membership function analysis ranked three genotypes as highly salt tolerant. • Na+ exclusion was found to be a major trait underlying salt tolerance. We assessed the effects of salinity stress on 48 genotypes of jamun (Syzygium cumini L. Skeels) including 20 monoembryonic and 28 polyembryonic types to identify the salt tolerant genotypes and the morpho-physiological traits that underpin salt tolerance. Salinity of irrigation water was gradually raised over a period of 21 weeks, from 2.0 to 12.0 dS/m. Control plants were irrigated using fresh water (0.70 dS/m). The experiment was conducted in a Completely Randomized Block Design with four replications. Salinity had a more repressive effect on shoot than on root biomass, regardless of the seedling type, reflecting that roots might tolerate salt concentrations high enough to inhibit the growth of shoots. Salinity had little effects on the maximum quantum yield of photosystem II (F v /F m), and the relative leaf chlorophyll in most genotypes evaluated. Salt-induced decreases in photosynthetic assimilation were generally greater in genotypes with inherently high photosynthetic rates. Genotypes with strong capacities for Na+ exclusion (e.g., CSJ-18, and CSJ-19) were generally highly tolerant to salinity stress. Leaf Cl−concentrations under saline conditions were lower than Na+ concentrations, suggesting a more effective mechanism for Cl− exclusion. Leaf K+, Ca2+ and Mg2+ levels were not significantly different between control and salt treatments in both mono- and poly-embryonic types. The mean membership function value (MFV) was hardly different between mono- (0.5052) and poly-embryonic (0.5254) types, given quite similar reductions in plant height (∼22.0 %), leaf area (≤ 14.0 %), leaf (35–40 %), stem (∼40 %), and root (24–29 %) biomass, and net photosynthesis (∼64 %) as well as increases in leaf Na+ (79–85 %) and Cl− (70–76 %) under saline conditions. Based on mean MFV for all the traits, genotypes CSJ-19, CSJ-18 and CSJ-5 were found to be highly salt tolerant, whereas CSJ-1 and CSJ-31 were ranked as highly salt sensitive. We deduce that maintenance of leaf and root growth, reduced uptake of Na+, and preferential accumulation of K+, Ca2+ and Mg2+ could be the major traits underlying salinity tolerance in jamun. [Display omitted] [ABSTRACT FROM AUTHOR]

• Nutrient deficiency decreased the vegetative growth of Phalaenopsis to ambient CO 2 levels. • Elevated CO 2 alters nutrient availability, improving plant growth and SPAD value with deficient CAN levels (CAN0). • Elevated CO 2 decreased the biomass and photosynthetic efficiency with high CAN levels (CAN2−3). • Elevated CO 2 can be effectively used for Phalaenopsis cultivation with optimal CAN supply. Phalaenopsis Queen Beer 'Mantefon' is an orchid species that absorbs CO 2 at nighttime due to its crassulacean acid metabolism. These orchids originated from nutrient–poor environments in tropical forest understories. However, elevated CO 2 at nighttime influences plant nitrogen utilization for growth. This study investigated the leaf growth and photosynthetic responses in Phalaenopsis Queen Beer 'Mantefon' to varying ambient and elevated CO 2 (400 and 800 μmol⋅mol−1, respectively) and four nitrogen−based calcium ammonium nitrate (CAN) levels over 20 weeks: calcium, ammonium, and nitrate levels by 0.00, 0.00, and 0.00 mmol⋅L−1 (CAN0, control), 0.90, 0.55, and 2.97 mmol⋅L−1 (CAN1), 6.73, 1.11, and 6.05 mmol⋅L−1 (CAN2), and 12.80, 1.72, and 9.13 mmol⋅L−1 (CAN3), respectively. The phosphate and potassium levels were consistent across all CAN levels at 2.74 and 4.37 mmol⋅L−1, respectively. Elevated CO 2 levels showed no significant impact on the number of leaves in CAN1−3 plants yet increased with those with CAN0. Leaf area significantly increased with elevated CO 2 levels by 44 % (CAN0) and 26 % (CAN1). Strong correlations emerged between the number of leaves and leaf area, as well as between leaf area and root−to−shoot dry biomass ratio (R/S). Increasing CO 2 levels heightened SPAD chlorophyll in CAN0 plants, and SPAD and F 0 showed a strong correlation with elevated CO 2 and increasing CAN levels. The total dry biomass decreased in plants with high CAN (CAN and CAN3) compared to those with CAN0, regardless of CO 2 levels, and F v /F m dropped below 0.616 with high CAN under elevated CO 2. Phalaenopsis Queen Beer 'Mantefon' demonstrated augmented leaf growth and R/S under limited CAN (CAN0) and elevated CO 2 conditions, indicating improved resource allocation potential. The results suggest that supplying CO 2 in a greenhouse can effectively improve Phalaenopsis vegetative growth with limited nutrient conditions, which differs from growth aspects under ambient CO 2 levels. [ABSTRACT FROM AUTHOR]

• Melatonin maintains redox equilibrium (removing ROS and RNS), is a stress reduction agent, promotes root growth and development. • Encourages plant development, influences flowering and fruit ripening, prevents leaf senescence. • Improves gene expression and activity of enzymes, improves photosynthesis. • Shields plants from pathogen attack and influences other biochemical and physiological processes. Melatonin (N-acetyl-5-methoxytryptamine) is a biological indolamine. It is biologically synthesized in plants and can be used to promote sustainable agriculture. This molecule has multiple effects and a wide range of actions that are beneficial to plants. It plays an important role in plants as a modulatory agent (a bio-stimulator and plant growth regulator) that improves the plants tolerance to both biotic and abiotic stress (drought, waterlogging, severe temperatures, salt, alkalinity, chemical contaminants in soils (such as heavy metals, pesticides, and others), UV radiation). It acts as a stress-relieving hormone (regulates anti stress reactions) and as a bio-stimulator of plant growth. Melatonin maintains redox equilibrium (removing ROS and RNS), is a stress reduction agent, promotes root growth and development, encourages plant development, influences flowering and fruit ripening, prevents leaf senescence, improves gene expression and activity of enzymes, improves photosynthesis, shields plants from pathogen attack (regulates plant innate immunity, initiate defense responses) and influences other biochemical and physiological processes. This review explores these special functions of melatonin and how it impacts different plant systems specifically. Research is already ongoing in this field and through this compilation we can conclude that melatonin, a bio stimulator, is a crucial molecule that can be essential in increasing crop yields and nutraceutical values useful for addressing global food security issues. [ABSTRACT FROM AUTHOR]

• Melatonin is multifunctional nontoxic antioxidant biomolecule. • Melatonin regulates growth and development of Solanaceous vegetable crops. • Phytohormone reduced oxidative damage and enhanced antioxidant defense system. • Phytohormones enhanced the performance of horticultural crops under abiotic stress. Solanaceous vegetable crops are extensively consumed and cultivated around the world, however they are often subjected towards different abiotic stress conditions including cold, heat, drought, salt and heavy-metals toxicity. These stresses notably affect plant growth, yield, and quality. Novel Phytohormones plays a major role in managing crop responses to abiotic stress conditions, particularly those seen in Solanaceous vegetable crops. In this review, an overview of the physiological, morphological and molecular responses of Solanaceous vegetable crops to abiotic stresses, and the regulatory roles of the novel phytohormones in these responses, is furnished. Furthermore, the impact of abiotic stresses on the biosynthesis, metabolism and signaling pathways of major phytohormones, particularly melatonin (MEL), salicylic-acid (SA), jasmonic-acid (JA), strigolactones (SLs), brassinosteroids (BRs) and gamma-aminobutyric acid (GABA) is discussed. Consequently, phytohormones application remarkably boosts growth status of plant, leaf photosynthetic apparatus, root architecture system, osmolytes accumulation, and secondary metabolites production, and upregulates photosynthesis related gene expression. In addition, phytohormone regulates ascorbate-glutathione cycle and reduces cellular membrane damage, as well as maintains mineral nutrient homeostasis. Overall, the current review delivers a comprehensive overview of the recent studies on regulating roles of phytohormones for abiotic stresses in Solanaceous vegetables crops, which may serve as a valuable resource for researchers and breeders working for the enhancement of crop resilience and productivity in challenging environments. [ABSTRACT FROM AUTHOR]

• Leaf adaxial–abaxial polar establishment is crucial for leaf morphogenesis. • A novel leaf morphological mutant crsl with curled rod-shaped leaves and strikingly altered leaf adaxial–abaxial development was identified in Chinese cabbage. • BraA02g016100.3C (BrCRSL) gene is homologous to Arabidopsis MAB1 and encodes a putative mitochondrial PDH E1β subunit protein, which is the most likely causal gene for crsl and might serve as a new regulator of leaf polarity specification. • It's the first to identify BrCRSL function in leaf morphogenesis. Leaf morphogenesis requires precise genetic control and hormone regulation to develop into ideal plant architectures. Leaf flattening is an adaptive trait to obtain efficient photosynthesis, for which the leaf adaxial–abaxial polar establishment is of great importance. Herein, a novel leaf morphological mutant, curled rod-shaped leaf (crsl), was isolated and characterized from Chinese cabbage (Brassica rapa L. ssp. pekinensis) EMS-induced population. The leaves in crsl were slender and rod-shaped, with the abaxial side folded upwards and the distal side curled downwards, the mesophyll cells were loosely arranged, and the epidermal morphology was opposite on the adaxial and abaxial surface. Genetic analysis revealed that the curled rod-shaped leaf mutant phenotype was controlled by a dominate nuclear gene, named BrCRSL. MutMap and Kompetitive Allele Specifc PCR (KASP) genotyping demonstrated that BraA02g016100.3C was the most likely candidate for BrCRSL. Compared with the wild-type, a non-synonymous SNP mutation (C to T) occurred in the 8th exon of BraA02g016100.3C in crsl. BraA02g016100.3C is orthologous of Arabidopsis thaliana MAB1 (AT5G50850), which encodes a putative mitochondrial PDH E1β subunit protein and contributes to PIN-dependent auxin transport in organ development. The amino acid substitution from proline (P) to leucine (L) is conserved among the homologous proteins of BraA02g016100.3C. ​The crsl mutant exhibited abnormal auxin metabolism, primarily manifested by high level of L-tryptophan (TRP) accumulation that is the precursor of IAA biosynthesis. Furthermore, the expression of a wide range of leaf adaxial/abaxial polarity-related genes was affected in crsl. Our results contribute to a better understanding of the genetic control mechanism underlying leaf morphogenesis in Chinese cabbage and provide new insights into the auxin-related leaf axial growth. [ABSTRACT FROM AUTHOR]

Highlights • This study established a lettuce leaf area model based on TEP method under different light cycles in mini-plant factories. • Shortened light cycle makes the leaves compact and rounder which reduces self-shading. • Longer light cycle that closer to the circadian rhythms has growth advantage with slender and open leaves. • Different light cycle strategies has an advantage under different growth stages and plant density conditions. Abstract To establish an effective leaf area model in a mini plant factory with artificial lighting (mini-PFAL) environment, we conducted three experiments exposing lettuce plants to different light cycles. Three treatments were set up in the first experiment: 12-h/12-h (light/dark), 6-h/6-h (light/dark), and 3-h/3-h (light/dark). We analyzed the dynamic changes in the lettuce leaf area under different light cycles in a mini-PFAL and established a leaf area model based on the accumulated product of thermal effectiveness and photosynthetically active radiation (TEP) method. Data from two subsequent experiments were used to validate the lettuce leaf area model and uncover the difference in plant growth caused by different light/dark cycle patterns from a physiological perspective. Results show that the TEP and light cycle influenced lettuce leaf area significantly. Under 12-h/12-h (light/dark) treatment, lettuce growth was better than in 6-h/6-h (light/dark) and 3-h/3-h (light/dark) conditions within the same TEP. The light cycle appeared to significantly affect the leaf area as well as morphogenesis. The shape of lettuce leaves was slenderer and the leaf angle was steeper under the longer light cycle. We believed the different illumination durations in a single light cycle altered the functional relationships between phytochromes and led to different plant shapes. At the same time, the plant shape caused different light interceptions that affected the growth and leaf areas. A relative longer light period (6-h light/6-h dark) increased leaf stomatal conductance, net photosynthetic rate, and plant growth, compared to those of a shorter light period (3-h light/3-h dark). Based on these results, this study provides useful insights on regulation strategies related to light cycles and their effects on lettuce growth. [ABSTRACT FROM AUTHOR]

• An optical clearing technique suitable for grape mature leaf was established. • The morphological characteristics of both stoma and vein of grape leaf were presented during the process of leaf development. • The potential transcription factor regulating stoma/leaf vein were identified and discussed as well as leaf polarity and leaf expansion. The leaf functions through photosynthesis and determines the yield and quality of the grape (Vitis vinifera L.). Understanding the morphology, anatomy, and molecular regulation of leaf development can provide insight into the function of the leaf. In the present study, the microstructure of the vein and stomata was observed using an improved tissue clearing method, and differently expressed transcription factors (TFs) underlying leaf development were determined by transcriptome analysis in the 'Pinot Noir' grape. The process of stomata development from a single epidermal cell to a mature stomata cell was observed clearly under light microscopy by improving the method of tissue clearing. The onset of stomata formation in the leaf tip occurred prior to that in the central leaf, and developing stomata were observed in the center of the leaves at different development stages except for L5, when only mature stomata were present. The major vein was initiated before leaf unfolding (L1) and numbers of vessels increased underlying leaf growth. The shape of the vessel presented tapering. Freely ending veins were not observed until stages L4 and L5, and the vessels were different from other order veins in shape and ways of connection. Development-dependent differences between stomata and vein suggested differences in function during leaf development. A total of 445 TFs involved in leaf morphology and anatomy were identified. The members of the bHLH family (SCRM) and MYB family (MYB88) can contribute to stomata patterning during leaf development. Members of the TF families of ARF (ARF5), Dof (TMO6 and HCA2), HD-Zip III (HB14), and GRAS (SCR, SCL14 , and SCL28) were potential regulators involved in vein development. The grape orthologs of WOX9, TCP 4 , and GRF1-9 can participate in leaf outgrowth and expansion. These results will be helpful for our further study of the molecular regulation of leaf development and the relation between leaf structure and function, which can be applied to improve grape production. [ABSTRACT FROM AUTHOR]

• There is a close interaction between Fe nutrition and light perception in plants. • The tomato response mechanisms to Fe deficiency is highly light-dependent. • hp-1 tomato mutant is more tolerant to Fe deficiency. • au tomato mutant tend to accumulate less nutrients. Iron (Fe) is a micronutrient for plant development, as constituent of several photosynthesis- and respiration-related proteins and enzymes. Consequently, Fe deficiency leads to chlorosis in leaves and plant growth impairment. It has become increasingly evident that light signals coordinate iron homeostasis in plants. To further address new insights into how light is a fundamental part of Fe deficiency responses, we employed Micro-Tom (wild type, WT) tomato (Solanum lycopersicum L.) plants and high-pigment 1 (hp1) and aurea (au) photomorphogenic mutants, which exhibit an excessive light response and low light perception, respectively. Plant growth, pigment contents, oxidative status, and nutrient profile were analyzed. The results revealed the influence of the different genotypes on Fe deficiency responses. WT and au exhibited plant growth reduction under Fe deficiency. WT, hp1 and au demonstrated that Fe availability and light perception play fundamental roles in chlorophyll and anthocyanin biosynthesis. Lipid peroxidation was not increased for any genotype under Fe deficiency, indicating that mutations in light perception and signaling differentially modulate H 2 O 2 production and scavenging under this condition. Additionally, macronutrients and micronutrients were taken up and distributed differently among the different plant genotypes, tissues and Fe conditions analyzed. In general, the au plants accumulated lower amounts of nutrients (Ca, S, P, Mg, B and Zn) than the WT and hp1 genotypes regardless of the Fe concentrations. Our data clearly indicates that light perception and signaling influence Fe-dependent morphophysiological responses in plants, suggesting possibilities for biotechnological improvement of crops grown under Fe shortage. [ABSTRACT FROM AUTHOR]

• 'Orri' mandarin has a low parthenocarpic ability, in accordance with its low CcGA3ox1 gene expression, but the application of GA 3 does not increase fruit set. • Ringing branches performed 35-40 days after anthesis increases fruitlet growth rate. This effect correlates inversely with the fruitlet abscission rate, and positively with cell division, i.e., with the CcCYCA1.1 gene expression in the fruitlet, but not with the GA biosynthesis, i. e., with the CcGA3ox1 gene expression. • Ringing branches significantly increased CcPIN1 gene expression in the fruitlet. • Results suggest that ringing protects the fruitlet abscission zone mediated by polar auxin transport from the fruit, which allows the fruitlet to maintain carbohydrate assimilation and continue growing. Ringing branches is a technique which is widely used to increase the yield of Citrus cultivars with low parthenocarpic ability. When performed during the physiological fruitlet abscission stage it prevents fruitlet drop and increases the number of fruits harvested. This effect has been related with an increased carbohydrate supply, which requires an enhanced photosynthesis efficiency of leafy flowering shoots. Since ringing also reduces vegetative growth, both the number of shoots and the leaves per shoot, the mechanism by which the carbohydrate supply is increased should be revised. Our results show that ringing carried out at this stage maintains the ability of the ovary for cell division mediated by the availability of carbohydrates, as indicated by an increased CcCYCA1.1 expression. But this effect is not linked with an increase in GA 1 biosynthesis (CcGA3ox1 expression), as this occurs during fruit set; hence, hormones other than gibberellin must be controlling the physiological fruitlet abscission in response to ringing. We found that an increased expression of the auxin efflux carrier CcPIN1 gene suggests that ringing induces the auxin export out of the fruitlet and transport to the abscission zone (AZ-C), thus inhibiting its activation and allowing carbohydrates supply to the fruitlet which, thus, prevents abscission and continues growth. [Display omitted] [ABSTRACT FROM AUTHOR]

• Growth season is the main factor of secondary metabolites accumulation. • Phenolics of raspberry leaves gradually increase in growth season. • TPC, TFC and Q3GR, K3R, EA accumulate in apical leaves. • Condensed tannins, epicatechin and procyanidin B1 accumulate in basal leaves. • Leaves of all cultivars can be harvested twice in early summer and late autumn. Raspberry leaves with high polyphenols have high utilization value, but the accumulation trend of phenolics in raspberry leaves in different growing seasons, cultivars, and leaf positions, is not clear. The utilization of leaves and raspberry comprehensive income are limited due to the uncertain factors. Therefore, the content changes of chlorophyll a, chlorophyll b, carotenoids, total phenolic content (TPC), total flavonoids content (TFC), saponins, hydrolyzed tannins and condensed tannins of raspberry leaves from May to October, in annual-fruiting (AF) raspberry (cv. Heritage) and biennial-fruiting (BF) raspberry (cv. Reveille, cv. Tulameen and cv. Australian Red), and three leaf positions were investigated. Eighteen phenolic compounds were identified in which quercetin-3-glucuronide, kaempferol-3-rutinoside, ellagic acid, chlorogenic acid, epicatechin and procyanidin B1 were quantitatively analyzed by HPLC-MS. The results showed that chlorophyll a, chlorophyll b, carotenoids showed a parabolic trend of rising first and then falling, while TPC, TFC, hydrolyzed tannins, condensed tannins and saponins showed a gradual increase trend from May to October. The total accumulation of secondary metabolites was the Heritage, Australian Red, Tulameen and the Reveille from high to low. The apical leaves accumulated TPC, TFC and quercetin-3-glucuronide, kaempferol-3-rutinoside, ellagic acid, while the basal leaves accumulated condensed tannins and saponins. Overall, growth season was the main factor affecting the accumulation of secondary metabolites, followed by cultivar and leaf positions. Therefore, according the properties of cultivars, it can be recommended that AF and BF cultivar leaves can be harvested twice in early summer and late autumn after reproductive shoot preservation, while the leaves of BF cultivar without fruiting shoots can be extensively harvested once in late autumn. [ABSTRACT FROM AUTHOR]

• It firstly reported that the grapevine powdery mildew, Erysiphe necator NAFU1, effector CSEP087 molecular mechanism in interaction between powdery mildew and grapevine. • CSEP087, which is upregulated during En NAFU1 infection contains a secreted signal peptide verified by a yeast secretion assay. Expression of CSEP087 in grape leaves facilitates the powdery mildew growth and suppresses the production of reactive oxygen species (ROS) in grapevine. • CSEP087 interactes with a grape arginine decarboxylase VviADC, which is screened by yeast two-hybrid system. • Expression of VviADC in grape leaves inhibited the powdery mildew growth and promoted the ROS production during En NAFU1 infection. Grapevine (Vitis vinifera) is suffering from the fungal pathogen powdery mildew, which affects grape production worldwide. Powdery mildew secretes a large number of effectors into plant cells, which modulate the innate immune system to promote colonization of the infection. Many studies have been conducted on the interactions between pathogens and plants, but the working mechanism of the effectors in the interaction between powdery mildew and grapevine has not been reported. In this study, we identified the CSEP087 effector from the grapevine powdery mildew isolate, Erysiphe necator NAFU1, which was upregulated during infection and contained a signal peptide that was secreted into the plant cells as verified by a yeast secretion assay. The expression of CSEP087 in grapevine leaves facilitated the growth of powdery mildew and suppressed the production of reactive oxygen species (ROS). CSEP087 interacted with VviADC, an arginine decarboxylase from grapevine, as screened by a yeast two-hybrid system. VviADC is a conserved protein in horticultural and model plants, particularly localized at the recognition and catalytic sites of the enzyme active center. The expression of VviADC in grapevine leaves inhibited the growth of powdery mildew and promoted ROS production, including hydrogen peroxide in the plants. In addition, VviADC increases the enzymes related to ROS scavenging activities. Our results demonstrate that the powdery mildew effector CSEP087 targeted VviADC, which is a regulator of hydrogen peroxide production and plant immunity. This finding advances our understanding of the role of effectors in the grapevine-powdery mildew interaction. [ABSTRACT FROM AUTHOR]

Highlights: [•] High and low root temperatures affected dry matter partitioning of 5 peach rootstocks. [•] At 21°C, the root mass ratio was maximised. [•] At 21°C, the leaf, stem and shoot mass ratios were minimised. [•] The growth of plants exiting dormancy was influenced by root temperature. [•] Root temperature may affect rootstock-scion development. [ABSTRACT FROM AUTHOR]

Highlights: [•] MB-CO2 sterilized F. oxysporum f. sp. melonis and P. carotovorum subsp. carotovorum. [•] There were no changes of inorganic components in hydroponic solution by the MB-CO2. [•] The CO2-dissolved hydroponic solution had little effect on growth of leaf lettuce. [•] MB-CO2 was proposed to become to a new technique for disinfecting a hydroponic solution. [ABSTRACT FROM AUTHOR]

Highlights: [•] Shoot regeneration occurred during dark condition. [•] TDZ did not cause hyperhydricity in regenerated plantlets. [•] The best shoot regeneration rate (64%) from callus was observed on medium containing 16μM TDZ. [•] Regenerated shoots and donor shoots were identical with respect to the ploidy level. [•] We reported a simple protocol for indirect regeneration of some pear cultivars. [ABSTRACT FROM AUTHOR]

• Phosphate concentration control at lower levels is a viable option. • The phosphate concentration is controlled using pH measurement only. • Equal growth rates achieved at phosphate levels 10 times lower. Urban hydroponics is expanding on a global scale. This provides environmentalists with an ideal opportunity to couple sustainability principles to the development of the sector. A primary concern in hydroponics is the generation of large amounts of nutrient laden wastewater. Unlike conventional agriculture, the water effluent typically exits the urban farm via a dedicated outlet, where water quality can be monitored and regulated. It is therefore imperative to develop processes in which the quality of the exit water is part of the design objective. Minimisation of nitrogen and phosphorous in the effluent is key in this regard. This study presents an affordable technique to control phosphate levels in a hydroponic unit. The technique relies solely on continuous pH measurement from which the pH-buffering capacity of the nutrient solution is calculated. The pH-buffering capacity is then used as an inferential measurement to control the phosphate concentration in solution. This concentration can then be controlled at significantly lower levels and thereby reduce phosphate spillage proportionally. Experiments were performed in which the phosphate concentration was controlled at 1 ± 0.08 mM (representing standard protocol), 0.2 ± 0.03 mM and 0.1 ± 0.03 mM. No significant variation in plant growth rate or leaf mass fraction was observed in the runs with lower phosphate concentrations, suggesting that optimal growth is possible at phosphate levels ten times lower than conventional practice. Since the phosphate concentration in the hydroponic outlet is directly proportional to the load of phosphate spillage, the results are encouraging from a nutrient pollution perspective. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Pistachio cultivation requires the use of rootstock because grafting is the only form of vegetative propagation. The main commercial rootstocks are Pistacia integerrima L., Pistacia atlantica Desf., Pistacia terebinthus L. and Pistacia vera L. Pistachio is considered to be a drought and saline-resistant crop; however, there is little information describing varietal responses of rootstocks to water stress. Some studies have suggested that P. terebinthus L. is the most drought and cold resistant rootstock. The effect of the rootstock on the water relations of the grafted plant is crucial for improving crop performance under water stress conditions and for developing the best irrigation strategy. This work studied the physiological response to water stress of pistachio plants (P. vera L. cv. Kerman) grafted onto three different rootstocks P. terebinthus L., P. atlantica Desf. and a hybrid from crossbreeding P. atlantica Desf.× P. vera L. Plant physiological responses were evaluated during a cycle of drought and subsequent recovery in potted plants. Parameters measured were soil moisture, trunk diameter, leaf area, leaf number, leaf and stem dry weight, stem water potential, leaf stomatal conductance. The results showed different responses of cv. Kerman depending on the rootstock onto which it had been grafted. The hybrid rootstock was associated with a higher degree of stomatal control and reduced leaf senescence compared to P. atlantica and P. terebinthus, despite being associated with the most vigorous shoot growth. P. terebinthus enabled very effective stomatal control but was also associated with the most rapid leaf senescence. P. atlantica was associated with less vigorous shoot growth and similar levels of water stress as occurred with the others rootstocks under conditions of high evaporative demand, which was associated with lower stomatal control. The selection of the most effective rootstock choice for different environmental conditions is discussed. [Copyright &y& Elsevier]

Abstract: Pomegranate leaves are an important source of potentially healthy bioactive compounds. Changes in total phenolics, flavonoids, alkaloids and antioxidant activities in pomegranate leaves were recorded from April 18th to September 16th, 2007. Total levels of phenolics and flavonoids decreased significantly in the early stages of leaf growth, and then increased gradually until the end of September. However, concentrations of total alkaloids increased during leaf growth and development. Antioxidant activities in pomegranate leaves were significantly correlated with the level of total phenolics and flavonoids. All bioactive compounds measured from pomegranate leaves increased during leaf growth and development. These trends suggest that the optimum picking time for tea is before May and bioactive compounds should be extracted from pomegranate leaves after August. [Copyright &y& Elsevier]

Abstract: The Andean seed crop quinoa (Chenopodium quinoa Willd.) is traditionally grown under drought and other adverse conditions that constrain crop production in the Andes, and it is regarded as having considerable tolerance to soil drying. The objective of this research was to study how chemical and hydraulic signalling from the root system controlled gas exchange in a drying soil in quinoa. It was observed that during soil drying, relative g s and photosynthesis A max (drought stressed/fully watered plants) equalled 1, until the fraction of transpirable soil water (FTSW) decreased to 0.82±0.152 and 0.33±0.061, respectively, at bud formation, indicating that photosynthesis was maintained after stomata closure. The relationship between relative g s and relative A max at bud formation was represented by a logarithmic function (r 2 =0.79), which resulted in a photosynthetic water use efficiency of 1 when FTSW>0.8, and increased by 50% with soil drying to FTSW 0.7–0.4. Mild soil drying slightly increased ABA in the xylem. It is concluded that during soil drying, quinoa plants have a sensitive stomatal closure, by which the plants are able to maintain leaf water potential (ψ l) and A max, resulting in an increase of WUE. Root originated ABA plays a role in stomata performance during soil drying. ABA regulation seems to be one of the mechanisms utilised by quinoa when facing drought inducing decrease of turgor of stomata guard cells. [Copyright &y& Elsevier]

Abstract: A protocol was developed for organogenesis from immature leaflet explants derived from mature seeds of peanut. Immature leaflets pre-incubated on MS medium supplemented with 13.32μM BAP+4.95μM NAA for 7 days, turned green and enlarged. The enlarged green leaflets produced multiple shoot buds after 1–2 cycles of sub-culture on MS medium supplemented with 13.32μM BAP. Three cycles of shoot buds on the elongation medium (13.32μM BAP) produced 6.17±0.47 elongated shoots per explant. The shoot bud formation was genotype independent. All elongated shoots rooted on the medium containing 4.95μM NAA. The complete protocol gave efficient (>81%) direct organogenesis, leading to the development of plantlets within 4 months. [Copyright &y& Elsevier]

Abstract: Three ornamental bromeliads, i.e. Aechmea ‘Maya’ (CAM), Aechmea fasciata ‘Primera’ (CAM) and Guzmania ‘Hilda’ (C3) were grown under greenhouse conditions at ambient (380ppm) and elevated (750ppm) CO2. The effects of long-term exposure (34 weeks) to elevated CO2 on growth and morphological traits constituting the ornamental value were assessed. Aechmea ‘Maya’ and A. fasciata ‘Primera’ showed a different growth response to elevated CO2 exposure. Aechmea ‘Maya’ showed for both CO2 concentrations an equal biomass enhancement throughout the experimental period. In accordance leaf micromorphology remained unaffected. For A. fasciata ‘Primera’ CO2 fertilisation led to a decreased biomass production (25% less fresh and dry weight) due to a reduced total leaf area (41%) and lower leaf thickness (9%). These responses of both Aechmea hybrids are quite uncommon for CAM plants. Doubling the atmospheric CO2 concentration stimulated growth for Guzmania ‘Hilda’ shown by an increase in total leaf area (34%) and leaf thickness (11%). However, the surplus in biomass production (57% more fresh weight and 69% more dry weight) was gained only in the first 22 weeks of the experiment as afterwards acclimation occurred. For all three bromeliads elevated CO2 exposure led to adverse effects on the ornamental value. Leaves from high CO2 grown plants displayed a visual paler green colour than leaves from control plants due to halving of the total chlorophyll content. Furthermore, allometric relations changed between leaf length and leaf width causing a more compact plant shape. This ultimately resulted in the loss of the typical plant shape for ornamental bromeliads with long and slender leaves. Overall the results in the current study show that long-term exposure to elevated CO2 does not always lead to enhanced biomass production. Moreover it can lead to adverse effects on the ornamental value. Thus, it is apparent that caution is needed with the application of CO2 fertilisation in commercial ornamental cultures. The CO2 plant response can seriously differ among individual species in one family and even in one genus. Therefore it is important to realise that the study of only one representative for a certain plant family or a genus is not adequate to make the proper interpretations concerning general CO2 responses! [Copyright &y& Elsevier]

• Mixed red and blue light promote photosynthetic efficiency in tomato seedlings. • Carbon assimilation levels detected differences under red and blue light. • Understanding endogenous hormone function on plant growth under red and blue light. • Mixed red and blue light improve photomorphogenesis in tomato seedlings. The light frequency of red (R) and blue (B) plays a crucial role within plant growth cycle. Whereas, the relationship between the metabolic pathways involved in photosynthesis and carbohydrate accumulation in tomato seedling and hormone regulation still needs further investigation. This research comprehensively analyzed changes in leaf anatomy, stomatal traits, pigment content, gas exchange parameters, chlorophyll fluorescence, Rubisco and Calvin cycle-related enzyme expression and activities, as well as endogenous hormones biosynthesis in tomato (Solanum lycopersicum L.) seedlings, which radiated by four light qualities, including monochromatic white light (W), B, R and mixed light of R and B (RB). The findings showed the biomass accumulation as well as CO 2 assimilation were greatly increased in seedlings under B and especially under RB light. Their leaves were also thicker, and stomatal conductance, levels of pigment, photosynthetic electron transport capacity, and the photosynthetic rate were enhanced. In addition, enzyme expression level and activity related to the Calvin cycle were up-regulated. Moreover, RB-induced growth was accompanied by a significant inhibition in gibberellin (GA) concentration as well as an increment in auxin (indole-3-acetic acid (IAA)) in stem and root. Overall, photosynthesis of RB-treated seedlings was positively regulated by leaf anatomy and photosynthetic electron transportation as well as maintaining the activation states of the Calvin cycle, and then inducing changes in carbohydrate accumulation. In addition, both GA and IAA were found to be involved causally in the increased shoot and root biomass of tomato seedlings under RB treatment. [ABSTRACT FROM AUTHOR]

• The Zn treatments promoted leaf growth and reduced leaf thickness. • The Zn treatments inhibited root elongation and enhanced its thickness. • Leaf mitotic index (MI) increased, and root MI decreased with the Zn concentration. • Leaf and root nucleolar activity was reduced by the increase of Zn concentration. • 'Verdelho' and 'Dozenlinho Branco' were more tolerant to Zn than 'Bastardo'. Zinc (Zn) is an essential micronutrient to plants, but in most of the vineyard soils, its amount surpasses the threshold value recommended by the European Union. With this work, we intended to evaluate the growth, morpho-histological traits and nucleolar activity in leaves and roots of three grapevines (Vitis vinifera L.) varieties ('Donzelinho Branco', 'Verdelho' and 'Bastardo'). Forced cuttings of those varieties were placed in hydroponic solutions supplemented with 1.5, 3 and 5 mM Zn for two weeks to extrapolate their tolerance to Zn. Hoagland's nutritive solution (0 mM Zn) was used as control. The Zn treatments stimulated the leaf growth in all varieties, confirmed by the increase of the leaf mitotic index (MI). Leaf growth was higher in 'Donzelinho Branco' treated with 5 mM Zn, but it was accompanied by a significant reduction of the leaf thickness. The increase of Zn concentration contributed to the roots thickening and the decrease of the root MI, mean nucleolar number and area. The inhibition of root elongation and the leaf and root nucleolar activity changes seen in the Zn-treated plants are compatible with osmotic stress responses. The integration of the multidisciplinary data of this work allowed us to suggest that 'Verdelho' and 'Donzelinho Branco' were more tolerant than 'Bastardo' to higher Zn concentrations. [ABSTRACT FROM AUTHOR]

• Seed priming improved germination performance and seedling establishment under salt stress conditions. • Seed-priming conferred to cauliflower plants to better decipher subsequent salt stress. • H 2 O 2 as a pre-germination stimulus, helped cauliflower plants to prevent itself from subsequent oxidative injuries and so that better memory of subsequent salt stress. In the present study, we examined the impact of three seed priming agents; H 2 O 2 , GA 3 and NaCl on the oxidative stress status in primed seed germination dynamics and growth establishment of cauliflower seedlings subsequently grown under salt stress. Results showed beneficial effect of all priming agents in improving plant responses to salinity. However, specific differences, depending on development stage, organ and priming type were recorded. At the germination stage, GA 3 was the most advantageous agent to accelerate seedling emergence. At the seedling stage, seedlings obtained from redried H 2 O 2 -primed seeds showed the highest level of seed superoxide anion (5-fold) and H 2 O 2 (4-fold), resulting in higher MDA content (2.4-fold). At the same time, priming seeds with H 2 O 2 triggered the overall seedling antioxidant defense, including enzymatic (SOD, CAT, GPX and APX) and non-enzymatic systems (AsA, GSH and proline). Salinity restricted the growth of both leaves (43%) and roots (60%) of cauliflower seedlings issued from unprimed seeds. Under primed conditions, the relative contribution of GA 3 and NaCl was more associated with growth establishment and osmotic adjustment. However, H 2 O 2 role was greatly correlated with the antioxidant defense. Indeed, salt-treated seedlings issued from H 2 O 2 -primed seeds showed the lowest levels of superoxide anion, H 2 O 2 and MDA, resulting in the highest activities of the entire antioxidant systems. These findings support the hypothesis that cauliflower plants, when exposed to salt stress benefit from H 2 O 2 seed priming, as a pre-germination stimulus, to prevent itself from subsequent oxidative injuries, which supports the hypothesis of "stress memory" of subsequent salt stress. [ABSTRACT FROM AUTHOR]

Abstract: Glycinebetaine (GB) plays a role in stress tolerance in many plant species that synthesize this compatible solute; however, many plants are unable to naturally synthesize GB or synthesize very low levels. In an effort to increase stress tolerance, there have been attempts to artificially increase the concentration of GB in plants by selection for high accumulating species, genetic engineering, or exogenous application. Grape is an economically important temperate zone fruit species that is subject to multiple environmental stresses, such as temperature extremes, that lead to reductions in fruit yield and quality. Application of GB to grapevines at critical periods (e.g. prior to spring frosts) may protect plants and maintain yields. We examined endogenous levels of GB, and the effects of exogenous GB on growth and physiology of grapevine. Field-grown plants had very low endogenous levels of GB. There was no consistent genetic variation for GB either among a set of 13 cultivars or clones of Chardonnay or Pinot noir. Application of GB to plants grown in a controlled environment slightly reduced growth rates, resulting in a lower shoot leaf area at concentrations of 50, 100, or 200mM. Application of GB also increased the average number of days to maximum leaf area, and increased specific leaf weight. Concentrations of 100 or 200mM resulted in growth cessation and phytotoxicity. Leaf osmotic potential decreased only slightly with GB application. Leaf water potential and leaf relative water content were unaffected by GB. Photosynthetic rate of GB-treated plants increased in one experiment, but overall, our results reflect previous work indicating that GB has little or no affect on physiological parameters in non-stressed plants. We have established endogenous GB levels in grape and non-toxic application levels for further work on the potential effects of GB on grapevine stress tolerance. [Copyright &y& Elsevier]

• Gladiolus is one of the most popular bulbous cut flowers worldwide. • Response of gladiolus to water deficit using the FTSW approach is still unknown. • The threshold FTSW for transpiration is higher in the reproductive phase. • During the reproductive phase, water deficit reduces the flower stem quality. • Water deficit reduces leaf appearance rate, delaying the harvest point. The objective of this study was to evaluate the response of transpiration and leaf growth of gladiolus cultivars to a drying soil represented by the FTSW. Three experiments (E1, E2 and E3) were individually carried out in 20 pots, with four gladiolus cultivars. Plants did not experienced water deficit until they had less than seven leaves in E1, four leaves in E2 and, four and seven leaves in E3. At these stages, water deficit was imposed in 10 pots of each experiment, while the other 10 pots remained without water deficit. The FTSW, transpiration and leaf growth were measured daily, during the period of water deficit. Results indicated that the threshold FTSW for transpiration is higher when water deficit occur during the reproductive phase. We concluded that the FTSW threshold for NTR in gladiolus varies depending on the developmental stage at which the water deficit is applied, being higher when it occurs during the reproductive phase and lower when it occurs during the vegetative phase. Water deficit reduces leaf appearance rate in gladiolus, delaying the harvesting point of the flower stems. [ABSTRACT FROM AUTHOR]

• Great camas daughter bulbs develop during the summer rest period. • Great camas, common camas, and meadow death camas require chilling prior to emergence. • The chilling optimum for great and common camas is approximately 80 days for year old bulbs with no heat treatment. • This research informs storage and bulb forcing protocols for these understudied species. Great camas (Camassia leichtlinii (Baker) S. Watson [Asparagaceae]) and common camas (C. quamash (Pursh) Greene) are two of the most culturally and ecologically significant native geophyte species in the US Pacific Northwest. Like many geophytes, seasonal thermoperiodicity affects their growth and development. The daughter bulb of great camas grows and develops during the summer rest period. Increasing the duration of the summer rest period results in longer leaves in the subsequent growing season. Great camas, common camas, and meadow death camas (Toxicoscordion venenosum (S. Watson) Rydb. [Melanthiaceae]) require a period of chilling during their winter rest period to induce leaf emergence, and as the duration of chilling increases (1) the odds of leaf emergence increases, (2) the period between the cessation of chilling and leaf emergence decreases, and (3) leaf growth in the first week after leaf emergence increases. These results inform growers as to the proper storage methods for these species during their rest periods. Additionally, the chilling optimum, here defined as the amount of chilling at 4.6 °C that minimizes the duration of the winter rest period, is approximately 80 days for both great camas and common camas. However, this optimum was determined without considering a potential interaction with the heat treatment. Knowing the optimum duration of heat treatment and chilling may allow growers to manipulate native bulb species into emerging for multiple growing cycles in a single year, which could expedite their production. [ABSTRACT FROM AUTHOR]

• Seven AcDHN genes were identified and cloned in kiwifruit. • The expansion of the AcDHN gene family relied primarily on segmental duplication. • Some AcDHNs were involved in the regulation of leaf or fruit development. • Most AcDHNs were induced by various abiotic stresses or ABA treatment. Dehydrins (DHNs) play a vital role in enhancing plant tolerance to abiotic stresses. In kiwifruit, there has not been a comprehensive and systematic study undertaken on the DHN gene family to date. In this study, seven AcDHNs were identified and cloned in kiwifruit, which were divided into two subgroups, YnSKn- and SKn-types. AcDHN2 / AcDHN7 and AcDHN4 / AcDHN5 originated evolutionarily from segmental duplication. AcDHN2 and AcDHN7 were highly expressed in leaves, stems, roots, and fruits. During leaf growth, the expression levels of AcDHN1 , AcDHN4 and AcDHN5 were downregulated; during fruit growth, AcDHN1 and AcDHN6 were upregulated, while AcDHN4 and AcDHN5 were downregulated. These findings suggest that these genes may be involved in the regulation of leaf or fruit development. Under various abiotic stresses (drought, high and low temperatures, and salt stress) and abscisic acid treatment, the transcription levels of AcDHN1 , AcDHN2 , AcDHN6 , and AcDHN7 were significantly increased. AcDHN3 was only induced by low temperature stress, and AcDHN4 and AcDHN5 only slightly responded to high temperature and salt stress. These results lay a foundation for further study of their function under various stress conditions. [ABSTRACT FROM AUTHOR]

Produced biochar from mulberry wood by slow pyrolysis; added to the soil of the pots to mitigate negative effect of salt stress and improve chemical characteristics of soil as well as growth and nutrient of the plant. • Growth characteristics of summer savory under salinity stress are influenced by biochar usage. • Biochar can change the nutrient of salt-affected soils and plants. • Biochar is a useful way to modify chemical characteristics of soil under salinity stress. • Biochar is a suitable amendment for alleviating negative effects of salt stress. • Nutrient uptake of the plant is affected by biochar usage under salinity stress. Salinity is one of the environmental factors limiting plant growth and development. Biochar has various effects on the chemical properties of soil and through soil fertility enhancement, can enhance plant productivity. This study was aimed to study the effect of biochar on the growth, physiological traits and mineral nutrient contents of summer savory (Satureja hortensis L.) and some chemical and elemental properties of the soil under salinity condition. Thus, a pot factorial experiment based on a completely randomized design with four replications was performed. Experimental treatments included three levels of biochar (non-biochar, 1 and 2% of total pot mass) and four different NaCl levels (0, 3, 5 and 7 dS m−1). The results showed that the growth traits (fresh and dry weight of the shoots and roots, main root length and volume) and leaf nutrients of summer savory were improved by increasing soil biochar (especially 2% of total pot mass) under salinity stress. Using biochar as 2% of total pot mass, at 5 dS m−1 increased proline content. In addition, this study indicated that soils containing biochar were rich in nutrients content and showed the highest pH (8.18), OC (1.63 %) and N content (0.14 %) at 2% biochar under no salinity. The highest EC (29.8 dS m/m), CEC (10.6 Cmol(+) kg−1), Ca2+ (45.4 meq/L), Mg2+ (32.4 meq/L), Na+ (180 meq/L) and Cl- (318 meq/L) were observed at 7 dS m-1 salinity by using 2% biochar. In general, biochar can modify the soil nutrient situation to overcome the detrimental effects of NaCl. The positive effect of biochar on the growth, nutrient uptake, and soil properties encourage the application of biochar to overcome nutrient deficiency and improve the plant growth. [ABSTRACT FROM AUTHOR]

• Overexpression of DkGAL2 , a persimmon β-galactosidase gene, increases leaf area in Arabidopsis. • Overexpression of DkGAL2 delays dark-induced senescence in Arabidopsis. • Overexpression of DkGAL2 enhances tolerance to abotic stress in Arabidopsis Plant β-galactosidases (EC 3.2.1.23) have activities related to cell wall galactan-containing polysaccharides metabolism and cell wall remodeling, though their precise functions have not yet been established. We previously isolated a persimmon β-galactosidase gene, DkGAL2 , with high levels of transcripts were detected in leaves and during fruit developments. Here, abundant DkGAL2 transcripts were observed in expanding persimmon leaves, increasing with dark-induced senescence but remaining constant with glucose supplementation under dark conditions. The promoter sequence of DkGAL2 harbors several cis-elements related to leaf expansion. To further investigate the role of DkGAL2 , ectopic overexpression of DkGAL2 in Arabidopsis was performed, and the leaves of DkGAL2 -overexpressing plants exhibited high growth rates and large leaf areas. Moreover, DkGAL2 overexpression enhanced tolerance to abscisic acid (ABA), methyl jasmonate (MeJA) and NaCl, with plants have long root lengths and high galactose contents, suggesting a role for DkGAL2 in abiotic stress responses. In addition, DkGAL2 -transgenic plants showed delayed senescence under dark conditions, and some ABA signaling-related genes were significantly suppressed in transgenic plants during senescence compared to WT plants. Together, these results demonstrate that by affecting cell wall modification, DkGAL2 is involved in leaf expansion and senescence. The functions of DkGAL2 might affect ABA signaling during senescence. [ABSTRACT FROM AUTHOR]

• Ca concentrations and distributivity before and after tipburn were determined. • The influence of plant growth rate on the tipburn was evaluated by new approach. • Tipburn was caused by the decrease in the distribution of Ca in new leaves. Tipburn (leaf-tip necrosis) is severe problem for the production of lisianthus [ Eustoma grandiflorum (Raf.) Shinn.] cultivars. A previous study has suggested that tipburn of 14 lisianthus cultivars are caused by the inability to translocate sufficient quantities of calcium (Ca) to the tips of the upper leaves. However, systematic studies are not available that identify the differences in Ca concentrations and distributivity before and after the onset of tipburn. To address this insufficiency in our knowledge, we used the lisianthus cultivars 'Umihonoka' (UH), 'Voyage green' (VG), and 'Voyage pink' (VP) and determined Ca concentrations and the dry weight of each organ at weekly intervals for 8 weeks. In addition, we evaluated the Ca distributivity from the ratios of the relative Ca increase rate (RGR Ca) to the relative plant growth rate (RGR) by applying growth analysis methods. UH did not exhibit tipburn. In contrast, VG and VP exhibited tipburn after 4 and 5 weeks, respectively. At the same time, the concentrations and distributions of Ca in the roots increased and those of whole and new leaves decreased in each cultivar. Thus, it is suggested that the distribution of Ca in new leaves of the tipburn-sensitive cultivars VG and VP was below the threshold, which caused tipburn. Moreover, it was demonstrated that decreases in the distribution of Ca in whole and new leaves were mainly caused by not increase of the relative leaf growth rate (RGR leaf) but decrease of the relative leaf Ca increase rate (RGR leaf-Ca). We conclude that this approach more rigorously evaluates the influence of plant growth rate on the incidence of tipburn. Thefore, tipburn exhibited by lisianthus cultivars was caused by decreased distributions of Ca in new leaves, which was associated with an increase in the distribution of Ca in roots. [ABSTRACT FROM AUTHOR]

• The hexane extract of Stevia rebaudiana leaves inhibit in more than 50% the in vitro. • The hexane extract of S. rebaudiana leaves contained austroinulin as one of the bioactive compounds. • The ethanol, hexane and aqueous extracts that were evaluated in tomato plants inhibit the manifestation of vascular wilting symptoms and provide an antifungal effect. • The hexane extract of S. rebaudiana leaves stimulated the growth of non- F. oxysporum -inoculated tomato plants. The excessive application of agrochemicals to control phytopathogenic fungi has caused the development of resistant strains, damage to the environment and harmful effects on human health. The use of plant extracts represents an alternative to such chemicals because they have been shown to be effective in the control of phytopathogens and to be environmentally friendly since their secondary metabolites are biodegradable quickly. This study evaluated the antifungal activity of extracts of different polarity obtained from Stevia rebaudiana B. leaves against Fusarium oxysporum , a fungus that causes great losses in tomato cultivation. Hexane extract at a concentration of 833 ppm inhibited in vitro mycelial growth by more than 50%. Column chromatographic separation of the hexane extract resulted in a fraction with greater inhibitory activity and spectroscopic analysis of it revealed austroinulin to be the main component. In vivo tests with F. oxysporum infected tomato plants showed that all plants treated with the extract were taller, and had greater aerial and root dry weights that were significantly greather than those of control plants inoculated with F. oxysporum to which no extracts was applied. In treatments without F. oxysporum inoculum, applying hexane extract resulted in greater plant height and aerial dry weight. This indicates that the extracts contain secondary metabolites, including austroinulin, that not only inhibit the growth of F. oxysporum but that could also be acting as biostimulants. The aqueous, ethanol and hexane extracts added to tomato plants inoculated with F. oxysporum had an antifungal effect and were not phytotoxic. [ABSTRACT FROM AUTHOR]