Metarhizium rileyiis a wide spread insect fungi with a good biocontrol potentiality to various pests, particularly noctuid insects. However, it is characterized by its slow growth, its sensitivity to abiotic stress, and the slow speed of kill to pests, which hinder its use compared with other entomopathogenic fungi. In this study, the responses ofM. rileyito eight types of lipids were observed; among the lipids, oleic acid and linoleic acid significantly promoted the growth and development ofM. rileyiand enhanced its stress tolerances and virulence. An additional mechanistic study demonstrated that exogenous oleic acid and linoleic acid significantly improved the conidial germination, appressorium formation, cuticle degradation, and cuticle infection, which appear to be largely dependent on the up-regulation of gene expression in growth, development, protective, and cuticle-degrading enzymes. In conclusion, exogenous oleic acid and linoleic acid enhanced the stress tolerances and virulence ofM. rileyivia protecting conidial germination and promoting cuticle infection. These results provide new insights for the biopesticide development ofM. rileyi.
Xun Zhan,Jian Chen,Yanhua Kang,Zhaozhe Yang,Guomin Wu,Zhenwu Kong
In the application of waterborne coatings, enhancing the water resistance and mechanical properties of coating films derived from waterborne coatings has been a critical challenge in need of urgent resolution. To tackle this issue, we propose an innovative strategy that involves surface modification of cellulose nanocrystals (CNC) using long-chain alkyl alcohols and the preparation of polyurethane composite films with excellent hydrophobicity by compounding the modified CNC (C-CNC) with waterborne polyurethane (WPU). Using a custom mold, we achieved surface hydrophobic functionalization. This study delves into the impact of CNC on the hydrophobic composite film, particularly focusing on its contribution to film morphology, thermal properties, and mechanical properties, significantly enhancing its hydrophobicity. Experimental results demonstrate that the mold with a rough surface constructs numerous rough and porous structures on the coating film surface, significantly enhancing its hydrophobicity. Notably, the C 28 –CNC/WPU composite film prepared using octacosanol-modified CNC exhibits the best hydrophobicity, with a water contact angle reaching 122.80°. This strategy of preparing hydrophobic coating films through a simple and effective method not only overcomes limitations of waterborne coatings in terms of water resistance and mechanical properties but also holds significant potential for environmentally friendly coatings, offering new insights for waterborne coating development.
Ziqi Zhang,Yue Jiang,Xinyu Zhao,Jianbo Qiao,Guanqun Du,Yaxun Fan,Yilin Wang
Surfactants are essential components of pesticide adjuvants, facilitating the solubilization of active ingredients, promoting droplet deposition on hydrophobic or superhydrophobic leaf surfaces, and enhancing uptake by plant tissues. However, the effect of deposited surfactant droplets on the interactions with plant waxes remains poorly understood. In this study, spherical micelles with tunable hydrophobicity were prepared by assembling fatty acids of varying alkyl chain lengths─decanoic (C10), lauric (C12), myristic (C14), and palmitic (C16) acids─with the branched organic base tetrabutylammonium hydroxide. Aqueous droplets containing more hydrophobic micelles exhibit slower retraction upon a high-speed impact on hydrophobic wax films, maintain larger contact areas during evaporation, and demonstrate a stronger solubilization of hydrophobic pesticides. Increasing the chain length of the fatty acid enhances both micellar self-assembly and surface activity in solution. To mimic plant leaf wax, 1-octacosanol films with a water contact angle of ∼120° were employed. Micelles with higher hydrophobicity display increased surface activity, faster molecular diffusion, and stronger interactions with wax molecules, resulting in larger retention areas after deposition and evaporation. These interactions also improve the fluidity of the wax layer, potentially facilitating pesticide penetration into the leaves. This work highlights the critical role of micelle–wax interactions in determining surfactant performance as pesticide adjuvants and provides insights into optimizing droplet behavior and pesticide efficacy.
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