Albino Maggio

Summary: Sodium is an essential element for animal growth and survival. Here we test the hypothesis that plants exposed to insect feeding can translocate sodium from the feeding site to other plant organs as a defense strategy against phytophagous insects, which need sodium in their diet. By modulating leaf sodium levels in tomato and by profiling the gene expression of key plant sodium transporters in response to insect feeding, we assessed sodium redirection pathways as affected by leaf damage and the impact of different sodium levels on food preference and intake, growth and development of Spodoptera littoralis larvae. We demonstrated that upon S. littoralis attack, tomato plants removed sodium from the feeding site by relocating it basipetally from the leaf to the root, through a coordinated regulation of the sodium transporters HKT1;1 and HKT1;2 . We also showed that the leaf damage by S. littoralis larvae was positively correlated with sodium concentration and that low sodium plants negatively affected food preference, larvae growth and development. These results shed light on a novel mechanism of plant response to herbivore insect damage, providing new insights on the role of sodium in plant–insect interactions.

Biofuels can play an important role to reduce fossil fuels consumption and decrease carbon dioxide emissions. However, current biofuels derived from food crops can exacerbate food security concerns due to their competition for cropland and resources. Second‐generation biofuels obtained from non‐food crops can represent a promising opportunity to overcome this conflict. Safflower ( Carthamus tinctorius L .), an under‐utilised crop (UUC), shows promise for biofuel production due to its oil properties and resilience in extreme/unsuitable environments. In this study, we evaluated the response of two safflower genotypes CWL990L (CWL) and Oscar (OS) under two different water treatments: well‐watered (100% of ETc) and half‐watered (HW) (50% of ETc) across three locations in Southern Italy. CWL maintained high shoot biomass, seed yield and oil yield under HW conditions in the two deepest soils, whereas OS showed reductions up to 75% and 62% in biomass and seed yield, respectively. CWL had a reduced relative water content by only 6% (vs. 20% in OS), increased leaf mass per area by 26%, and developed a root system with 70% steeper root angle. In contrast, OS showed a much more limited plasticity in these traits. However, we observed significant variations in productivity across locations due to the different pedoclimates. In conclusion, safflower holds great potential as a sustainable biofuel feedstock. These results also demonstrate that resilient genotypes that require moderate agronomic inputs can maintain good yields while adapting to diverse environmental conditions.

This article is focused on the comprehensive evaluation of alleyways to scale-invariant feature transform (SIFT) and random sample consensus (RANSAC) based multispectral (MS) image registration. In this paper, the idea is to extensively evaluate three such SIFT- and RANSAC-based registration approaches over a heterogenous mix containing Triticum aestivum crop and Raphanus raphanistrum weed. The first method is based on the application of a homography matrix, derived during the registration of MS images on spatial coordinates of individual annotations to achieve spatial realignment. The second method is based on the registration of binary masks derived from the ground truth of individual spectral channels. The third method is based on the registration of only the masked pixels of interest across the respective spectral channels. It was found that the MS image registration technique based on the registration of binary masks derived from the manually segmented images exhibited the highest accuracy, followed by the technique involving registration of masked pixels, and lastly, registration based on the spatial realignment of annotations. Among automatically segmented images, the technique based on the registration of automatically predicted mask instances exhibited higher accuracy than the technique based on the registration of masked pixels. In the ground truth images, the annotations performed through the near-infrared channel were found to have a higher accuracy, followed by green, blue, and red spectral channels. Among the automatically segmented images, the accuracy of the blue channel was observed to exhibit a higher accuracy, followed by the green, near-infrared, and red channels. At the individual instance level, the registration based on binary masks depicted the highest accuracy in the green channel, followed by the method based on the registration of masked pixels in the red channel, and lastly, the method based on the spatial realignment of annotations in the green channel. The instance detection of wild radish with YOLOv8l-seg was observed at a mAP@0.5 of 92.11% and a segmentation accuracy of 98% towards segmenting its binary mask instances.

Weeds are a fundamental component of agroecosystems and, if not appropriately managed, can cause severe crop yield losses. New perspectives on weed management are required, because current approaches, such as herbicide application or soil tillage, have significant environmental and agronomic drawbacks. We propose the concept of “neutral weed communities,” which are weed communities that coexist with crops and do not negatively affect crop yield and quality compared with weed-free conditions. Management practices that promote neutral weed communities can enable reduced use of herbicides and soil tillage while enhancing ecosystem services and biodiversity. We report scientific evidence of neutral weed communities and survey ecological explanations for why different weed communities have different effects on crop production. We also propose two weed management approaches for attaining neutral weed communities. The first approach aims to maximize weed biodiversity using traditional approaches such as cropping system diversification and integrated weed management. Higher weed biodiversity is associated with lower dominance of competitive weed species that reduce crop yield. The second approach relies on modern tools such as robots and biotechnology to manipulate the density of specific weed species. This approach can remove highly problematic species and minimize niche overlap between the weeds and crops. Given the complexity of interactions among crops, weeds, and other components of the agroecosystem, we highlight the need for multidisciplinary research to illuminate mechanisms that determine the neutrality of weed communities.

Biostimulants have rapidly and widely been adopted as growth enhancers and stress protectants in agriculture, however, due to the complex nature of these products, their mechanism of action is not clearly understood. By using two algal based commercial biostimulants in combination with the Solanum lycopersicum cv. MicroTom model system, we assessed how the modulation of nitrogen metabolites and potassium levels could contribute to mediate physiological mechanisms that are known to occur in response to salt/and or osmotic stress. Here we provide evidence that the reshaping of amino acid metabolism can work as a functional effector, coordinating ion homeostasis, osmotic adjustment and scavenging of reactive oxygen species under increased osmotic stress in MicroTom plant cells. The Superfifty biostimulant is responsible for a minor amino acid rich-phenotype and could represent an interesting instrument to untangle nitrogen metabolism dynamics in response to salinity and/or osmotic stress.

Abiotic stresses adversely affect crop production causing yield reductions in important crops, including tomato (Solanum lycopersicum L.). Among the different abiotic stresses, drought is considered to be the most critical one, since limited water availability negatively impacts plant growth and development, especially in arid and semi-arid areas. The aim of this study was to understand how biostimulants may interact with critical physiological response mechanisms in tomato under limited water availability and to define strategies to improve tomato performances under drought stress. We investigated the physiological responses of the tomato genotype ‘E42’ grown in open fields under optimal conditions (100% irrigation) and limited water availability (50% irrigation) treated or not with a novel protein hydrolysate-based biostimulant (CycoFlow, Agriges, BN, Italy). Plants treated with the protein hydrolysate showed a better water status and pollen viability, which also resulted in higher yield under drought stress compared to untreated plants. The treatment with the biostimulant had also an effect on antioxidant contents and activity in leaves and fruits depending on the level of irrigation provided. Altogether, these results indicate that the application of protein hydrolysates on tomato improved plant performances under limited water availability and in different experimental fields.

Biostimulants hold great potential for developing integrated sustainable agriculture systems. The rhizobacteria Azotobacter chroococcum strain 76A and the fungus Trichoderma harzianum strain T22, with demonstrated biostimulant activity in previous systems, were evaluated in Triticum durum cv Creso for their ability to enhance growth and tolerance to drought stress. Growth and drought tolerance were evaluated in conditions of low and high soil nitrogen, with two levels of water stress. T. harzianum increased plant growth (+16%) under control conditions and tolerance to moderate drought stress (+52%) under optimal fertilization, while A. chroococcum conferred a growth penalty (−28%) in well-watered conditions under suboptimal fertilization and increased tolerance only under extreme drought stress (+15%). This growth penalty was ameliorated by nitrogen fertilization. T. harzianum abundance was found to be positively correlated to extreme soil drying, whereas A. chroococcum-induced tolerance was dependent on soil nitrogen availability. These results indicate that while biostimulants may enhance growth and stress tolerance, nutrient availability soil and environmental conditions heavily influence these responses. These interactions should be considered when designing biostimulant products targeted to specific cultural conditions.

Abiotic stresses will be one of the major challenges for worldwide food supply in the near future. Therefore, it is important to understand the physiological mechanisms that mediate plant responses to abiotic stresses. When subjected to UV, salinity or drought stress, plants accumulate specialized metabolites that are often correlated with their ability to cope with the stress. Among them, anthocyanins are the most studied intermediates of the phenylpropanoid pathway. However, their role in plant response to abiotic stresses is still under discussion. To better understand the effects of anthocyanins on plant physiology and morphogenesis, and their implications on drought stress tolerance, we used transgenic tobacco plants (AN1), which over-accumulated anthocyanins in all tissues. AN1 plants showed an altered phenotype in terms of leaf gas exchanges, leaf morphology, anatomy and metabolic profile, which conferred them with a higher drought tolerance compared to the wild-type plants. These results provide important insights for understanding the functional reason for anthocyanin accumulation in plants under stress.

Abiotic stress adversely affects crop production, causing yield reductions in important crops, including tomato (Solanum lycopersicum). Among different abiotic stresses, drought is considered to be the most critical one since limited water availability negatively impacts plants growth and development, especially in arid or semi-arid areas. This study aimed to understand how biostimulants may interact with critical physiological response mechanisms in tomatoes under limited water availability and to define strategies to improve tomato performances under drought stress. We investigated physiological responses of the tomato genotype ‘E42’ grown in an open field under control conditions (100% irrigation) and limited water availability (50% irrigation) and treated or not with a novel plant-based biostimulant named CycoFlow (Agriges, BN, Italia). Plants treated with the biostimulant showed an increase in stomatal conductance. The highest yield per plant was registered under the 100% water regimens in biostimulant-treated plants. Biostimulant-treated plants had higher pollen viability (+50.94% under water deficit) and higher fruit weight (+56.13% under water deficit) compared to non-treated plants. The treatment with the biostimulant had also an effect on antioxidants and pigments content in leaves and fruits. Altogether, these results indicate that the application of the biostimulant CycoFlow to tomato plants improved plant performances under limited water availability.