Exposure to invasive weeds in pasturelands may result in significant losses and toxicity in forage crops. These species may also contain a compound that may be toxic as well as beneficial depending upon the effect induced. The Ministry of Environment of the Republic of Korea has now recognized Solanum carolinense (Horsenettle)—an invasive weed species—as a potential threat to forage crops in pasturelands and to the entire agro-ecosystem. As a forage crop, Festuca arundinacea (Tall fescue) is one of the major economical crops and diets of livestock; in this study, the competition patterns of Solanum carolinense and Festuca arundinacea were examined with respect to their seeding ratios and growth periods. In addition, an extract from the root of Solanum carolinense (SCE) was prepared and treated at 2500 ppm and 5000 ppm in a Festuca arundinacea plant to observe its effect. The experimental results showed that as the growth period of the Horsenettle and the SCE treatment increased, the germination rate, plant height, root length, fresh weight, and dry weight of the tall fescue were significantly decreased. Moreover, the SCE treatment significantly increased the quantities of reactive oxygen species (O₂⁻ and H₂O₂), antioxidants (Catalase and Peroxidase), and endogenous phytohormones (Abscisic acid and Salicylic acid), and simultaneously decreased the superoxide dismutase content in the tall fescue shoots. Furthermore, we identified several glycoalkaloids from the SCE extract, among which Solanidan-3-ol, (3β,5α)’ possessed a higher number (52%). Based on these results, we predicted that the Solanidan-3-ol, (3β,5α)’ present in horsenettle has a major role in imposing phytotoxicity on agricultural crops. The glycoalkaloids in the Solanum species have been reported to possess both phytotoxic and therapeutic uses. Based on this concept, we believe that the compound available in Solanum carolinense could be used in developing crop protection or medicinal products through broader research. Conversely, our findings also showed the probable risk of horsenettle to the agro-ecosystem, especially in terms of forage production.

Introduction: Ambient temperature-induced hypocotyl elongation in Arabidopsis seedlings is sensed by the epidermis-localized phytochrome B (phyB) and transduced into auxin biosynthesis via a basic helix-loop-helix transcription factor, phytochrome-interacting factor 4 (PIF4). Once synthesized, auxin travels down from the cotyledons to the hypocotyl, triggering hypocotyl cell elongation. Thus, the phyB-PIF4 module involved in thermosensing and signal transduction is a potential genetic target for engineering warm temperature-insensitive plants. Objectives: This study aims to manipulate warm temperature-induced elongation of plants at the post- translational level using phyB variants with dark reversion, the expression of which is subjected to heat stress. Methods: The thermosensitive growth response of Arabidopsis was manipulated by expressing the single amino acid substitution variant of phyB (phyB[G515E]), which exhibited a lower dark reversion rate than wild-type phyB. Other variants with slow (phyB[G564E]) or rapid (phyB[S584F]) dark reversion or light insensitivity (phyB[G767R]) were also included in this study for comparison. Warming-induced transient expression of phyB variants was achieved using heat shock-inducible promoters. Arabidopsis PHYB [G515E] and PHYB[G564E] were also constitutively expressed in rice in an attempt to manipulate the heat sensitivity of a monocotyledonous plant species. Results: At an elevated temperature, Arabidopsis seedlings transiently expressing PHYB[G515E] under the control of a heat shock-inducible promoter exhibited shorter hypocotyls than those expressing PHYB and other PHYB variant genes. This warm temperature-insensitive growth was related to the lowered PIF4 and auxin responses. In addition, transgenic rice seedlings expressing Arabidopsis PHYB[G515E] and PHYB[G564E] showed warm temperature-insensitive shoot growth. Conclusion: Transient expression of phyB variants with altered dark reversion rates could serve as an effective optogenetic technique for manipulating PIF4-auxin-mediated thermomorphogenic responses in plants. (c) 2024 The Authors. Published by Elsevier B.V. on behalf of Cairo University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Globally, cadmium (Cd) stress dramatically reduces agricultural yield. Illite, a natural clay mineral, is a low-cost, environmentally acceptable, new promising method of reducing the heavy metal (HM) stress of cereal crops. In research statistics, there is little research on stress tolerance behavior of Illite (IL) on an experimental soybean plant. In the present study, we took IL and examined it for tolerance to Cd, as well as for other plant-growth-promoting (PGP) characteristics in Glycine max (soybean). The results showed that applying clay minerals in different concentrations enhanced the level of SA (defense hormone) and reduced the level of ABA (stress hormone). Cd 1 mM significantly reduces plant growth by altering their morphological characteristics. However, the application of IL significantly enhanced the seedling characteristics, such as root length (RL), 29.6%, shoot length (SL), 14.5%, shoot fresh biomass (SFW), 10.8%, and root fresh biomass (RFB), 6.4%, in comparison with the negative control group. Interestingly, IL 1% also enhanced the chlorophyll content (C.C), 15.5%, and relative water content (RWC), 12.5%, in all treated plants. Moreover, it resulted in an increase in the amount of superoxide dismutase (SOD), phenolics, and flavonoids in soybean plants, while lowering the levels of peroxidase (POD) and H₂O₂. Furthermore, compared to control plants, soybean plants treated with the Illite exhibited increased Si absorption and lower Cd levels, according to inductively coupled plasma mass spectrometry (ICP-MS). Thus, the IL can operate as an environmentally beneficial biofertilizer and sustainable approach under Cd stress by promoting plant development by activating signaling events.

The application of N-acetylglucosamine (GlcNAc) and melatonin (Mel) in agriculture could be a promising avenue for improving crop resilience and productivity, especially under challenging environmental conditions. In the current study, we treated the cucumber plant with GlcNAc and Mel solely and combinedly under salt stress (150 mM) then studied photosynthetic attributes using the transient OJIP fluorescence method. The results showed that the combination of GlcNAc × Mel significantly improved the plant morphological attributes, such as root and shoot biomass, and also improved chlorophyll and photosynthetic components. The mineral elements such as K, Mg, Ca, and P were significantly elevated, whereas a lower influx of Na was observed in GlcNAc × Mel treated cucumber shoots. A significant reduction in abscisic acid was observed, which was validated by the reduction in proline content and the increase in stomatal conductance (Gs), transpiration rate (E), and substomatal CO₂ concentration (Ci). Furthermore, the activities of antioxidants such as polyphenol and flavonoid were considerably improved, resulting in a decrease in SOD and CAT with GlcNAc × Mel treatment. In addition, GlcNAc × Mel treatment dropped levels of the toxic radical Malondialdehyde (MDA) and elevated amino acids in cucumber shoots. These findings suggest that the combination of GlcNAc × Mel could be an effective elicitor for modeling plant metabolism to confer stress tolerance in crops.

Invasive weed species exhibit both advantages, such as the potential for allelochemicals in bioherbicide development, and risks, including their threat to crop production. Therefore, this study aims to identify an allelochemical from Solidago altissima, an invasive weed species. The dose-dependent effects of S. altissima shoot and root extracts (SSE, SRE) on the signaling in the forage crop Trifolium repens and germination in various weed species (Echinochloa oryzicola, Cyperus microiria, Alopecurus aequalis, Portulaca oleracea, and Amaranthus retroflexus) were evaluated. The results showed that the T. repens seedlings treated with root extracts exhibited a significant decrease in plant height, dry weight, and chlorophyll content, along with an increase in H₂O₂ levels. Additionally, antioxidant activities, such as superoxide dismutase, catalase, and peroxidase enzyme activities, were significantly elevated in T. repens treated with SRE. Moreover, SRE treatment significantly inhibited the seed germination of all tested weed species in a concentration-dependent manner. Gas chromatography-mass spectrometry analysis of S. altissima root extract identified a high concentration of methyl kolavenate, a clerodane diterpene predicted to act as a phytotoxic agent. These findings highlight the potential of S. altissima for the development of crop-protective agents while emphasizing its potential risks in agriculture.

Cobalt (Co), whose environmental release is escalating due to battery recycling and industrial activities, poses a growing threat to crop productivity despite its essential role as a micronutrient. Excessive Co disrupts cellular redox homeostasis, impairs photosynthesis, and markedly restricts plant growth; nevertheless, sustainable mitigation strategies remain limited. Although chitin-derived compounds have been suggested to enhance plant tolerance to certain abiotic stresses, the mechanisms underlying these responses and the potential advantages of combining chitin with chitinase-producing microorganisms remain unclear. Therefore, this study aims to clarify the physiological, biochemical, and molecular mechanisms underlying the ability of the chitinase-producing bacterium Paenibacillus illinoisensis JS80 and chitin to mitigate Co toxicity in soybean (Glycine max L.). Strain JS80 is a highly Co-tolerant rhizobacterium exhibiting chitinase activity of 144.55 mU mL^-1. Under Co toxicity, co-application of JS80 and chitin significantly enhanced biomass production and photosynthetic performance, and reduced the accumulation of reactive oxygen species (O₂^- and H₂O₂) and lipid peroxidation. These improvements were associated with the activation of pattern-triggered immunity, as evidenced by the upregulation of defense-related genes (GmCERK1, GmRLCK, GmCaMK, GmMAPKs, and GmWRKY), elevated salicylic acid levels, and elevated activities of antioxidant enzymes (SOD, CAT, GPx, and APx). These findings indicate how the co-application of the chitinase-producing bacterial strain JS80 and chitin activates abiotic stress signaling that interacts with biotic responses through shared signaling pathways. This interaction boosts Co stress tolerance and provides an effective, sustainable strategy to improve crop resilience under adverse environmental conditions.