A Nomogram Model for Predicting the Polyphenol Content of Pu-Erh Tea.

To investigate different contents of pu-erh tea polyphenol affected by abiotic stress, this research determined the contents of tea polyphenol in teas produced by Yuecheng, a Xishuangbanna-based tea producer in Yunnan Province. The study drew a preliminary conclusion that eight factors, namely, altitude, nickel, available cadmium, organic matter, N, P, K, and alkaline hydrolysis nitrogen, had a considerable influence on tea polyphenol content with a combined analysis of specific altitudes and soil composition. The nomogram model constructed with three variables, altitude, organic matter, and P, screened by LASSO regression showed that the AUC of the training group and the validation group were respectively 0.839 and 0.750, and calibration curves were consistent. A visualized prediction system for the content of pu-erh tea polyphenol based on the nomogram model was developed and its accuracy rate, supported by measured data, reached 80.95%. This research explored the change of tea polyphenol content under abiotic stress, laying a solid foundation for further predictions for and studies on the quality of pu-erh tea and providing some theoretical scientific basis.

Arbuscular mycorrhizal fungi symbiosis and food security

Under the threat of the COVID-19 pandemic, the number of people impacted by hunger around the world continued to rise in 2020. This fact undermines the worldwide ambition of feeding the world's ever-increasing population, which is expected to hit a record high by 2050. In contrast to this, in the twentieth century, food production increased dramatically, mostly owing to the invention and application of herbicides and nitrogenous and phosphorous fertilizers, breakthroughs in plant breeding, and genetic technology. However, despite the development of various technologies, many key crop yields plateaued a few decades ago. Climate change, the ever-increasing human population, depleted soil nutrients, water shortage, overuse of fossil energy, loss of biodiversity, onset of superweeds, and resistant insects and phytopathogens, among others, are the key factors hindering optimum crop production and thus food security. Interestingly, the symbiotic attributes of the obligatory symbionts, arbuscular mycorrhizal fungi (AMF), in agriculture have long demonstrated dependability and efficiency toward a wide range of agriculturally important crops. Strong advocacy and hopes are placed upon AMF as they are believed to curb the burdens brought about by the currently used unfriendly agricultural models. Factually, their ability to enhance crop growth and yield, to mitigate the hindrances perpetrated by abiotic (droughts, heat, and salinity) and biotic (pests and diseases) stresses, and to improve the nutrient content of processed food coupled with sustained agricultural soil texture/structures makes AMF a top alternative promising technology toward sustainable production in the context of the global food crisis and erratic climatic conditions. Nonetheless, the composition of AMF inoculants in terms of several individual and diverse taxa is the key factor to consider for the presumed success of such biological agents in the highly competitive rhizospheric conditions. This chapter aims at shedding light on the current world food security status and the major challenges faced in current agriculture and, finally, describes the attributes of AMF that could help in coping with the current drawbacks of the agricultural system for a flourishing future. © 2023 Elsevier Inc. All rights reserved.

Chapter 24 - Impact of climate change and COVID-19 pandemic on citrus industry

Long-term shifts in weather of a particular region refers to climate change. Now the climate change is no longer a regional phenomenon. It has assumed global proportions and all countries are affected. These shifts may be natural, such as through variations in the solar cycle. But mainly since the 1800s, human activities, growing population and industrialization have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas on one hand and destroying green cover/vegetation/forests on the other. US Environmental Protection Agency defines carbon sequestration as the process through which carbon dioxide (CO2) from the atmosphere is absorbed by trees, plants and crops through photosynthesis, and stored as carbon in tree trunks, branches, foliage and roots (biomass) and also in soils. The term “sinks” is also used to refer to forests, croplands, and grazing lands, and their ability to sequester carbon. Agriculture and forestry activities can also release CO2 to the atmosphere. Therefore, a carbon sink occurs when carbon sequestration is higher than carbon released during the same period. Technologies for climate change mitigation and adaptation is the need of the hour. Covid-19 pandemic disrupted citrus production and trade but citrus fruit and juice consumption has increased.

Special Issue on Functional Properties in Preharvest and Postharvest Fruit and Vegetables

A total of fourteen papers (ten research papers and four review papers) in various fields of horticulture are presented in this Special Issue, including such topics as the identification and accumulation of the bioactive compounds in various plant species;the effects of abiotic stresses on bioactive compound composition and content;and exploration of the best methods for bioactive compound extraction. [1], the authors investigated the nutritional profile and the antioxidant, antiproliferative, and antibacterial activities of five species of Brassica (cauliflower, broccoli, red cabbage, white cabbage, and Chinese cabbage);they found that these Brassica vegetables are excellent sources of polyphenols that showed moderate antiproliferative and antibacterial potential. [2], the effect of the bulk density and water-holding capacity of lignite substrate in comparison to mineral wool and the EC of nutrient solution on the plant morphological parameters, yield, and fruit quality of greenhouse cucumber were investigated, and the results suggest that both the substrate density and water-holding capacity positively affected the morphological features of the plants. In the fourth paper, reported by Karim and Yusof [4], it was found that the impregnation of spinach leaves with salicylic acid, γ-aminobutyric acid, and sucrose effectively improved the quality and storage ability by reducing chilling injury through improvement of the proline content.

Assessment of Uptake, Accumulation and Degradation of Paracetamol in Spinach (Spinacia oleracea L.) under Controlled Laboratory Conditions.

The occurrence and persistence of pharmaceuticals in the food chain, particularly edible crops, can adversely affect human and environmental health. In this study, the impacts of the absorption, translocation, accumulation, and degradation of paracetamol in different organs of the leafy vegetable crop spinach (Spinacia oleracea) were assessed under controlled laboratory conditions. Spinach plants were exposed to 50 mg/L, 100 mg/L, and 200 mg/L paracetamol in 20% Hoagland solution at the vegetative phase in a hydroponic system. Exposed plants exhibited pronounced phytotoxic effects during the eight days trial period, with highly significant reductions seen in the plants' morphological parameters. The increasing paracetamol stress levels adversely affected the plants' photosynthetic machinery, altering the chlorophyll fluorescence parameters (Fv/Fm and PSII), photosynthetic pigments (Chl a, Chl b and carotenoid contents), and composition of essential nutrients and elements. The LC-MS results indicated that the spinach organs receiving various paracetamol levels on day four exhibited significant uptake and translocation of the drug from roots to aerial parts, while degradation of the drug was observed after eight days. The VITEK® 2 system identified several bacterial strains (e.g., members of Burkhulderia, Sphingomonas, Pseudomonas, Staphylococcus, Stenotrophomonas and Kocuria) isolated from spinach shoots and roots. These microbes have the potential to biodegrade paracetamol and other organic micro-pollutants. Our findings provide novel insights to mitigate the risks associated with pharmaceutical pollution in the environment and explore the bioremediation potential of edible crops and their associated microbial consortium to remove these pollutants effectively.

Characterization and Optimization of a Conical Corona Reactor for Seed Treatment of Rapeseed

Plasma agriculture is a growing field that combines interdisciplinary areas with the aim of researching alternative solutions for increasing food production. In this field, plasma sources are used for the treatment of different agricultural goods in pre- and post-harvest. With the big variety of possible treatment targets, studied reactors must be carefully investigated and characterized for specific goals. Therefore, in the present study, a cone-shaped corona reactor working with argon was adapted for the treatment of small seeds, and its basic properties were investigated. The treatment of rapeseed using different voltage duty cycles led to an increase in surface wettability, possibly contributing to the accelerated germination (27% for 90% duty cycle). The discharge produced by the conical reactor was able to provide an environment abundant with reactive oxygen species that makes the process suitable for seeds treatment. However, operating in direct treatment configuration, large numbers of seeds placed in the reactor start impairing the discharge homogeneity.

Underutilized Fruit Crops of Indian Arid and Semi-Arid Regions: Importance, Conservation and Utilization Strategies

Nowadays, there is a large demand for nutrient-dense fruits to promote nutritional and metabolic human health. The production of commercial fruit crops is becoming progressively input-dependent to cope with the losses caused by biotic and abiotic stresses. A wide variety of underutilized crops, which are neither commercially cultivated nor traded on a large scale, are mainly grown, commercialized and consumed locally. These underutilized fruits have many advantages in terms of ease to grow, hardiness and resilience to climate changes compared to the major commercially grown crops. In addition, they are exceptionally rich in important phytochemicals and have medicinal value. Hence, their consumption may help to meet the nutritional needs of rural populations, such as those living in fragile arid and semi-arid regions around the world. In addition, local people are well aware of the nutritional and medicinal properties of these crops. Therefore, emphasis must be given to the rigorous study of the conservation and the nutritional characterization of these crops so that the future food basket may be widened for enhancing its functional and nutritional values. In this review, we described the ethnobotany, medicinal and nutritional values, biodiversity conservation and utilization strategies of 19 climate-resilient important, underutilized fruit crops of arid and semi-arid regions (Indian jujube, Indian gooseberry, lasora, bael, kair, karonda, tamarind, wood apple, custard apple, jamun, jharber, mahua, pilu, khejri, mulberry, chironji, manila tamarind, timroo, khirni).

UV and Visible Spectrum LED Lighting as Abiotic Elicitors of Bioactive Compounds in Sprouts, Microgreens, and Baby Leaves-A Comprehensive Review including Their Mode of Action.

Background: According to social demands, the agri-food industry must elaborate convenient safe and healthy foods rich in phytochemicals while minimising processing inputs like energy consumption. Young plants in their first stages of development represent great potential. Objective: This review summarises the latest scientific findings concerning the use of UV and visible spectrum LED lighting as green, sustainable, and low-cost technologies to improve the quality of sprouts, microgreens, and baby leaves to enhance their health-promoting compounds, focusing on their mode of action while reducing costs and energy. Results: These technologies applied during growing and/or after harvesting were able to improve physiological and morphological development of sprouted seeds while increasing their bioactive compound content without compromising safety and other quality attributes. The novelty is to summarise the main findings published in a comprehensive review, including the mode of action, and remarking on the possibility of its postharvest application where the literature is still scarce. Conclusions: Illumination with UV and/or different regions of the visible spectrum during growing and shelf life are good abiotic elicitors of the production of phytochemicals in young plants, mainly through the activation of specific photoreceptors and ROS production. However, we still need to understand the mechanistic responses and their dependence on the illumination conditions.

Interactive Effects of Drought and Saline Aerosol Stress on Morphological and Physiological Characteristics of Two Ornamental Shrub Species

Effects of drought and aerosol stresses were studied in a factorial experiment based on a Randomized Complete Design with triplicates on two ornamental shrubs. Treatments consisted of four levels of water container (40%, 30%, 20%, and 10% of water volumetric content of the substrate) and, after 30 days from experiment onset, three aerosol treatments (distilled water and 50% and 100% salt sea water concentrations). The trial was contextually replicated on two species: Callistemon citrinus (Curtis) Skeels and Viburnum tinus L. ‘Lucidum’. In both species, increasing drought stress negatively affected dry biomass, leaf area, net photosynthesis, chlorophyll a fluorescence, and relative water content. The added saline aerosol stress induced a further physiological water deficit in plants of both species, with more emphasis on Callistemon. The interaction between the two stress conditions was found to be additive for almost all the physiological parameters, resulting in enhanced damage on plants under stress combination. Total biomass, for effect of combined stresses, ranged from 120.1 to 86.4 g plant−1 in Callistemon and from 122.3 to 94.6 g plant−1 in Viburnum. The net photosynthesis in Callistemon declined by the 70% after 30 days in WC 10% and by the 45% and 53% in WC 20% and WC 10% respectively after 60 days. In Viburnum plants, since the first measurement (7 days), a decrease of net photosynthesis was observed for the more stressed treatments (WC 20% and WC 10%), by 57%. The overall data suggested that Viburnum was more tolerant compared the Callistemon under the experimental conditions studied.

The TPR- and J-domain-containing proteins DJC31 and DJC62 are involved in abiotic stress responses in Arabidopsis thaliana.

Molecular chaperones play an important role during the response to different stresses. Since plants are sessile organisms, they need to be able to adapt quickly to different conditions. To do so, plants possess a complex chaperone machinery, composed of HSP70, HSP90, J proteins and other factors. In this study we characterized DJC31 (also known as TPR16) and DJC62 (also known as TPR15) of Arabidopsis thaliana, two J proteins that additionally carry clamp-type tetratricopeptide repeat domains. Using cell fractionation and split GFP, we could show that both proteins are attached to the cytosolic side of the endoplasmic reticulum membrane. Moreover, an interaction with cytosolic HSP70.1 and HSP90.2 could be shown using bimolecular fluorescence complementation. Knockout of both DJC31 and DJC62 caused severe defects in growth and development, which affected almost all organs. Furthermore, it could be shown that the double mutant is more sensitive to osmotic stress and treatment with abscisic acid, but surprisingly exhibited enhanced tolerance to drought. Taken together, these findings indicate that DJC31 and DJC62 might act as important regulators of chaperone-dependent signaling pathways involved in plant development and stress responses.

Microbial Biostimulants as Response to Modern Agriculture Needs: Composition, Role and Application of These Innovative Products.

An increasing need for a more sustainable agriculturally-productive system is required in order to preserve soil fertility and reduce soil biodiversity loss. Microbial biostimulants are innovative technologies able to ensure agricultural yield with high nutritional values, overcoming the negative effects derived from environmental changes. The aim of this review was to provide an overview on the research related to plant growth promoting microorganisms (PGPMs) used alone, in consortium, or in combination with organic matrices such as plant biostimulants (PBs). Moreover, the effectiveness and the role of microbial biostimulants as a biological tool to improve fruit quality and limit soil degradation is discussed. Finally, the increased use of these products requires the achievement of an accurate selection of beneficial microorganisms and consortia, and the ability to prepare for future agriculture challenges. Hence, the implementation of the microorganism positive list provided by EU (2019/1009), is desirable.