Apolygus lucorum is one of the most important piercing-sucking insect pests of tea plant. In this study, we assessed the impact of intercropping young tea plants with garden pea Pisum sativum on the populations of A. lucorum and natural enemies, tea plant growth and metabolites, and soil nutrient status of tea plantation. Intercropping with flowering P. sativum var. arvense reduced the population density of A. lucorum, particularly between June 1, 2020, and June 15, 2021, with a peak reduction of 90.87%. The percentage of A. lucorum-damaged tea leaves in the tea-pea intercropping was also reduced, with the maximum reduction of 8.96% observed on June 15, 2021, in the intercropping group compared to the control. The tea-P. arvense intercrop had a minor impact on the populations of natural enemies, such as coccinellids, parasitoids, and syrphids in the tea plantations. The tea-pea intercropping increased the contents of soluble sugar, tea polyphenols, caffeine, and anthocyanins, and decreased the contents of free amino acids and catechins of the tea plant leaves, and finally improved the quality of tea. Effective phosphorus and quick acting potassium decreased significantly in the plots intercropped. Our research indicated that tea-pea intercropping has the potential to manipulate the population of A. lucorum and tea leaf damage, and improve tea quality, while also enhancing soil fertility in tea plantations. The findings from this study offer important insights into the use of intercropping as a sustainable agricultural practice.

Soil salinity, a critical environmental stressor, substantially impacts plant growth and productivity. It induces osmotic stress, disrupts ion homeostasis, and triggers the excessive production of reactive oxygen species (ROS), which can lead to oxidative damage within plant cells. To counteract these detrimental effects, plants have evolved sophisticated defense mechanisms, one of which involves the production of secondary metabolites (SMs). These SMs function as biostimulants that bolster antioxidative defenses and modulate signal transduction pathways, thus enhancing the plant's tolerance to salt stress. Recent evidence reveals SMs like sulforaphane (glucosinolate-derived) uniquely stabilize redox cofactors and reprogram stress-responsive miRNAs. Furthermore, they influence key signaling cascades, such as the mitogen-activated protein kinase (MAPK) pathway and various hormone-regulated pathways, which are instrumental in orchestrating adaptive responses to saline conditions. The regulation of SMs biosynthesis under salt stress is mediated by transcription factors like MYB, WRKY, and bHLH, which are essential for activating the genes involved in these metabolic pathways. Elucidating the intricate mechanisms by which SMs operate as biostimulants not only advances our understanding of plant stress responses but also paves the way for developing sustainable agricultural practices aimed at improving crop resilience in saline environments. This knowledge is instrumental for cultivating crops that can thrive under challenging soil conditions, ultimately contributing to global food security.

Heavy metals (HM) in agricultural soils are a significant threat to crop productivity, adversely affecting plant growth and development through various physiological and biochemical mechanisms. Among the HM, nickel (Ni) has been reported to be increasingly accumulated in the soil and is a serious threat to human health via the food chain. Poor seedlings growth and low-quality produce are major causes of Ni toxicity in plants. The current study aimed to assess the effect of activated pomegranate peel biochar (APPB) on morpho-physiological and biochemical processes of wheat grown in Ni-affected soil. Different treatments i.e. control, biochar, Ni, and biochar + Ni were designed under randomized complete block design with six replications of each treatment. The morphological, biochemical, and physiological responses were then evaluated. Present results revealed the growth decline in wheat seedlings subjected to Ni toxicity. Moreover, disturbances in photosynthetic pigments, metabolites, and thiol group were recorded in seedlings under excess of Ni content. The findings of this study demonstrate that the application of APPB supplementation significantly alleviated the negative effect of Ni on wheat seedlings and improved growth parameters by 171%, 83%, 330%, 78%, and 96% in shoot biomass, shoot length, root biomass, root length, and seedlings dry weight, respectively. Chlorophyll a, b, and total chlorophyll contents boosted by 44%, 83%, and 55%. Carbohydrate content also increased by 82%, while total phenols and flavonoids were reduced by 24% and 22%, respectively. The stunted growth and irregular photosynthesis were recorded in wheat seedlings due to nickel toxicity. Hence, APPB proved to be an effectives soil amendment, that may be used for improved crop growth with enhanced and increasing tolerance to metal stress through the modulation of defense indices.

Rice (Oryza sativa L.), a primary food source for a substantial portion of the world's population, faces a serious threat from bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo), leading to considerable yield reductions. The excessive use of synthetic pesticides not only affects soil health but also disrupts the community of organisms living in the soil. While some pesticides degrade quickly, others persist, leading to long-term environmental damage. To address these challenges, the aqueous extract of Terminalia arjuna (T. arjuna), was investigated as a sustainable alternative for controlling Xoo. The extract was prepared using a Soxhlet apparatus, and its antibacterial activity was assessed via zone of inhibition assays and bacterial growth inhibition studies. The results revealed significant antibacterial activity, with inhibition zones of 9.1 +/- 0.76 mm at 25 mu g/ml, 14.16 +/- 1.04 mm at 50 mu g/ml, and 15.5 +/- 1.31 mm at 100 mu g/ml. Furthermore, the antibacterial mechanism of the T. arjuna extract was investigated using computational approaches. For this molecular docking of CbsA, LipA, T3SEs, PDF, and Ddl was conducted with the phytochemicals of T. arjuna. Further molecular dynamics simulation analysis shows that 3-Hydroxyspirost-8-en-11-one can inhibit Ddl and CbsA, while 9-Oximino-2,7-diethoxyfluorene and 2-Naphthalene methanol can interact with T3SEs and PDF, respectively resulting inhibition of growth of Xoo. These findings highlight T. arjuna's potential as an eco-friendly, natural pesticide to combat Xoo, offering a sustainable solution to reduce the reliance on synthetic pesticides and their detrimental environmental impact. Further field studies are needed to confirm these results.

Soil worms are among the most abundant and functionally diverse soil animals. However, they have been largely overlooked in studies on microplastic (MP) toxicity. MPs and plant secondary metabolites (PSMs) are ubiquitous in soil due to plant litter decomposition and heavy MP contamination, inevitably interacting and exerting combined toxicity on soil organisms. However, little research has been conducted on their joint effects. This study investigates the individual and combined toxic effects of polyethylene (PE) MPs and three PSMs (glycyrrhizic acid, tannic acid, and matrine) on the model organism Caenorhabditis elegans. Physiological and biochemical responses were assessed using fluorescence microscopy, image analysis, and statistical methods. After 42 h of exposure to PE MPs and/or PSMs, worm growth and development were negatively impacted. Under experimental conditions, matrine and PE MPs synergistically inhibited worm growth, exacerbated neurological damage, and induced oxidative stress. In contrast, glycyrrhizic acid and tannic acid alleviated PE MP-induced growth inhibition, mitigated oxidative stress, and demonstrated antioxidant properties that counteracted oxidative damage. This study offers new insights into the combined effects of MPs and PSMs in soil ecosystems, contributing to ecological risk assessments and pollution management strategies.

Several plant-associated microbes have the capability of ameliorating the adverse effects of salinity stress in plants. Such microbes produce metabolites, including proline, glycine betaine, and secondary compounds, like melatonin, traumatic acid, and beta-estradiol, which have been found to have a role in reducing salinity-induced damage in plant cells. While the effects of these metabolites have been studied, their application-related aspects remain underexplored. In this study, we investigated the salinity-stress-alleviating potential of metabolites derived from the endophytic bacterium Bacillus safensis BTL5. The microbial metabolites were extracted using the hexane-chloroform fraction method and identified through LC-HRMS analysis. Four metabolites (traumatic acid, beta-estradiol, arbutin, and alpha-mangostin), along with a fifth compound, melatonin, were initially screened for their salinity alleviation potential. Subsequently, two metabolites, i.e., arbutin and beta-estradiol, were evaluated for their impact on growth parameters and enzymatic antioxidant activities under 200 mM salt stress. The results revealed that arbutin and beta-estradiol significantly improved plant growth, chlorophyll content, and enzymatic activities while reducing oxidative damage. The dose-dependent effects highlighted optimal concentrations for maximum efficacy from these compounds under elevated salinity. This study signifies the potential of microbial metabolites in enhancing crop resilience to salinity, highlighting their role in sustainable agriculture. The outcomes of this study provide a baseline for the applied use of such microbial metabolites under field conditions.

Heavy metal contamination of the environment is increasing alarmingly due to increased anthropogenic activities. Among the various heavy metals, cadmium is a highly toxic heavy metal requiring urgent removal from soil. Strobilanthes alternata, a herbaceous terrestrial plant, has been reported to be an excellent plant for Cd phytostabilization. The present study investigated the effect of 25 ppm of 6-Benzylaminopurine (6-BAP) foliar sprays on the modulation of the physiological responses and elemental constitution in S. alternata grown in 250 mg/kg CdCl2 treated soil. The administration of 6-BAP effectively relieved the toxic effects of Cd by enhancing the total soluble sugar and alkaloid content of leaves by 56 and 250%, respectively, the total soluble protein content of roots by 27%, the phenolic content of roots and leaves by 9 and 10% respectively, and flavonoid content of roots and leaves by 53 and 6% respectively, in Cd-stressed S. alternata. Moreover, the 6-BAP-induced elevation of the thiol content of roots indicated amplified sequestration of Cd, thereby inflicting less damage to the aboveground portions of Cd + 6-BAP-treated plants. This inference was confirmed by SEM-EDX analysis, which revealed high Cd weight percentages in the roots of Cd + 6-BAP-treated plants. The ionomics and CHNS analysis confirmed that 6-BAP ascribable alterations in the elemental content and distribution helped the plant tolerate the adverse effects of Cd in S. alternata. Thus, the 6-BAP treatment could be used as a suitable and ecologically acceptable amendment to reduce Cd-induced damage and enhance the Cd phytostabilization potential in S. alternata.

Prunella vulgaris, an essential component of traditional Chinese medicine, is suitable for growing in soil with a pH value ranging from 6.5 to 7.5. However, it is primarily cultivated in acidic soil regions of China, where its growth is frequently compromised by acidic stress. Selenium (Se) has been recognized for its potential to enhance stress tolerance in plants. However, its role in acid-stress-induced oxidative stress is not clear. In this study, the effects of varying Se concentrations on the growth and quality of P. vulgaris under acidic stress were investigated. The results showed that acid stress enhanced antioxidant enzyme activities, non-enzymatic antioxidant substances, and osmolyte content, accompanied by an increase in oxidant production and membrane damage. Furthermore, it decreased the photosynthetic capacity, inhibited root and shoot growth, and diminished the yield of P. vulgaris. In contrast, exogenous application of Se, particularly at 5 mg L-1, markedly ameliorated these adverse effects. Compared to acid-stressed plants, 5 mg L-1 Se treatment enhanced superoxide dismutase, peroxidase, ascorbate peroxidase, and glutathione peroxidase activities by 150.19%, 54.94%, 43.43%, and 45.55%, respectively. Additionally, soluble protein, soluble sugar, and proline contents increased by 11.75%, 23.32%, and 40.39%, respectively. Se application also improved root architecture and alleviated membrane damage by reducing hydrogen peroxide, superoxide anion, malondialdehyde, and electrolyte leakage levels. Furthermore, it significantly enhanced the photosynthetic capacity by elevating pigment levels, the performance of PSI and PSII, electron transfer, and the coordination of PSI and PSII. Consequently, plant growth and spica weight were significantly promoted, with a 12.50% increase in yield. Moreover, Se application upregulated key genes involved in flavonoid and phenolic acid metabolic pathways, leading to elevated levels of total flavonoids, caffeic acid, ferulic acid, rosmarinic acid, and hyperoside by 31.03%, 22.37%, 40.78%, 15.11%, and 20.84%, respectively, compared to acid-stressed plants. In conclusion, exogenous Se effectively alleviated the adverse effects of acid stress by improving the antioxidant system, growth, and photosynthetic capacity under acid stress, thus enhancing the yield and quality of P. vulgaris.

Understanding the mechanisms that give rise to obstacles in the continuous cultivation of C. pilosula is essential for addressing or mitigating these challenges. The findings of this study suggest that repeated cultivation significantly reduced the content of polysaccharide in roots, and significantly increased the dead seedling rate in the field. The vascular bundles of the affected plant were extensively colonized by fungi. Furthermore, the root vascular bundles exhibit significant woodiness and corkiness, accompanied by cellular fractures and structural collapse. It was determined that the pathogenic endophyte is Fusarium oxysporum, and the exacerbated disease manifestation corresponds to an acute wilting type. Additionally, the root-zone soil microorganisms Cladosporium austroafricanum, Fusarium foetens, Fusarium petersiae, and Acaulium retardatum may significantly contribute to the yield-reducing phenomenon associated with continuous cropping. The proliferation of pathogenic bacteria during continuous cultivation initiates a complex interaction mechanism between the host plant and these pathogens. This process is characterized by a rapid increase in calcium ion (Ca2+) concentration, which subsequently leads to an upsurge in reactive oxygen species (ROS), particularly manifested as elevated levels of hydrogen peroxide (H2O2). Additionally, this response triggers thickening of cell walls and other immune mechanisms aimed at inhibiting the invasion of pathogenic bacteria. At the same time, to prevent ROS from inducing oxidative damage and triggering oxidative stress, there is a notable increase in both antioxidant enzyme activity and antioxidant substances content.

Fifteen new aliphatic metabolites, 2-methylpyrimidin-4(3H)-ones (1,2), 2-methoxy-2-methyl-1,2-dihydro-3Hpyrrol-3-ones (4a/4b, 5a/5b), butyrolactones (6-9), and aliphatic metabolites (16-20) as well as known pyridin2(1H)-one (3) and butyrolactone analogues (10-15) were obtained from the fermentation broth of Streptomyces antifungus isolated from the forest soil sample collected in Tengchong, China. Pyrimidin-4(3H)-one derivatives (1, 2) with an individual 2-methylpyrimidin-4(3H)-one skeleton is a kind of rarely reported compound and were firstly obtained from natural source. The structures of the new metabolites were elucidated by comprehensive spectroscopic analysis including data from experimental and calculated ECD spectra as well as Mosher's reagent derivative method. Compounds 1, 2, 18, and 19 exhibited optimal activity against Staphylococcus aureus with MIC values ranged from 12.5 to 50 mu g/mL. Further investigation revealed that 1 effectively inhibited biofilm formation and destroyed the preformed biofilm of S. aureus through oxidative damage, thereby exerting antibacterial effect.