Volume 21 Issue 2

Cotton is a vital fiber crop and major agricultural product worldwide. It was genetically engineered with Cry genes from Bacillus thuringiensis (Bt), producing insecticidal proteins called Cry (Bt) toxins. Bt cotton efficacy depends on the expression level of these toxins, which abiotic stress negatively affects. This study examined how salinity and drought stress influence Cry1Ac endotoxin levels in transgenic Bt cotton. Initially, Cry1Ac transgene presence was confirmed using polymerase chain reaction (PCR) and immunostrip assays. Genotypes were then subjected to varying levels of salinity and drought stress under controlled conditions. Bt toxin levels were quantified using a commercial ELISA kit. Results showed that increasing drought and salt stress led to a decline in Bt protein expression. Toxin concentrations in genotypes MNH-886 and Bt-121 varied across different exposure durations (days three and six) during salinity treatment. FH-113 and 3701 genotypes exhibited variable Bt protein expression in response to drought. Specifically, genotype FH-113 exhibited higher toxin levels under drought conditions (20% PEG) compared to genotype 3701. These findings indicate that genetic background influenced Bt toxin expression under drought stress. In conclusion, increasing salinity and drought result in decreasing Cry1Ac toxin levels, which may negatively impact insect resistance efficacy of Bt cotton.

Discarded tobacco leaves, a substantial agricultural by-product, represent an underutilized reservoir of bioactive phytochemicals. This study investigated the application of Supercritical Fluid Extraction (SFE) using CO₂ as a green technology for the recovery of tobacco oleoresin and α-tocopherol (Vitamin E). A Box-Behnken Design (BBD) integrated with Response Surface Methodology (RSM) was employed to optimize critical process variables: extraction pressure, temperature, and time. Statistical analysis identified the model-predicted optimum conditions as 21.3 MPa, 45.8 °C, and 63.4 min, yielding a maximum oleoresin recovery of 1.36%. This empirical result exhibited high concordance with the model prediction, validating the robustness of the optimization. Gas Chromatography-Mass Spectrometry (GC-MS) analysis demonstrated the tunable selectivity of the SFE process. The relative content of the high-value antioxidant Vitamin E was preferentially enriched to 19.1% under density-controlled conditions (25 MPa and 40 °C), minimizing the co-extraction of impurities. These findings established SFE as a superior, eco-friendly strategy for the valorization of tobacco residues, offering a sustainable pathway for the production of functional ingredients for pharmaceutical and cosmetic applications.

The effects of alkali treatment were studied relative to the physical, mechanical, and morphological properties of oil palm empty fruit bunch (OPEFB) and banana fibers to evaluate their potential as insulation materials. Both fibers were subjected to several concentrations of sodium hydroxide (3, 6, and 9 wt%). The impact of altered fibers was assessed using image analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), tensile testing, and thermal characterisation. The diameters of both fibers were decreased post-treatment, along with reductions in lignin and hemicellulose contents inside the fibers. Tensile strength was enhanced by 29% to 177% with 3% alkaline treatments for both fibers, while 6% alkali treatment yielded superior results for both fibers. The NaOH-treated OPEFB and BF exhibited increased residual content after thermogravimetric analysis and enhanced thermal stability. SEM analysis revealed that 3% alkali treatment eliminated silica bodies from OPEFB fiber, but 6% alkali treatment consistently filled the porosity of BF. The results implied that alkali treatment of OPEFB fiber significantly enhanced compatibility and mechanical properties, whereas treated BF had improved thermal stability for the manufacture of composite materials. Thus, alkali treatment effectively enhanced OPEFB and banana fibers, making them promising candidates for insulation material applications.

Ancient trees represent a significant ecological niche, constituting a vital habitat for a variety of species. Moreover, they serve as a cultural heritage and are worthy of preservation. The systematic analysis of volatile organic compounds (VOCs) in the wood of 11 species of ancient trees in Sichuan Province was performed using headspace gas chromatography–mass spectrometry (GC–MS). The results revealed significant compositional variations were demonstrated across different species of ancient trees. This finding indicates species-specific chemical defense mechanisms that have evolved in response to environmental adaptation. For instance, Magnolia sargentiana exhibited a preference for terpene-based preservation, whereas Acer grosseri demonstrated a preference for lipid-derived aldehydes. Terpenoids, which are the dominant constituents (e.g., α-cedrene and β-cedrene in Magnolia sargentiana and hexanal in Acer grosseri), demonstrate antimicrobial, insect-repellent and ecological signaling functions. These findings contribute to the advancement of knowledge regarding the role of VOCs in woods in ecological interactions and lay the foundation for the development of natural antimicrobial, flavorant, and medicinal products.