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A new method to engineer zein films with controlled surface morphology and hydrophilicity has been developed. The resulting surface morphology and surface hydrophilicity have been studied by tapping mode atomic force microscopy (TP-AFM) and a combination of water contact angle measurements and X-ray photoelectron spectroscopy (XPS), respectively. Our AFM results revealed that zein films cast from acetic acid showed much smoother surfaces as compared to those cast from ethanol aqueous solutions. Furthermore, zein films of controlled hydrophilicity have been engineered through the use of UV/ozone treatment, which can efficiently decrease the water contact angles of zein films from approximately 80 degrees to less than 10 degrees within 130 s. XPS results suggest that the difference in surface hydrophilicity of zein films is due to the difference in surface elemental composition, and UV/ozone treatment converted some of the surface methyl groups mainly to carbonyl groups, therefore decreasing the water contact angles and increasing the surface hydrophilicity of zein films. This research opens up new opportunities of using zein as barrier materials and delivery vehicles for functional food ingredients, drugs, and dietary supplements.

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Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present sRNA sequencing data revealed that miR482 was in response to V. dahliae infection, but the function in potato is elusive. Here, we characterized potato miR482 family and its putative role resistance to Verticillium wilt. Members of the potato miR482 superfamily are variable in sequence, but all variants target a class of disease-resistance proteins with nucleotide binding site (NBS) and leucine-rich repeat (LRR) motifs. When potato plantlets were infected with V. dahliae, the expression level of miR482e was downregulated, and that of several NBS-LRR targets of miR482e were upregulated. Transgenic potato plantlets overexpressing miR482e showed hypersensitivity to V. dahliae infection. Using sRNA and degradome datasets, we validated that miR482e targets mRNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting (ta)-siRNAs, most of which target mRNAs of defense-related proteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived tasiRNA-mediated silencing on NBS-LRR-disease-resistance proteins. It is speculated that a miR482-mediated silencing cascade mechanism is involved in regulating potato resistance against V. dahliae infection and could be a counter defense action of plant in response to pathogen infection.Keywords: miR482; nucleotide binding site leucine-rich repeat; potato; sRNA; ta-siRNA; Verticillium dahliae; Verticillium wilt Citation: Yang L, Mu X, Liu C, Cai J, Shi K, Zhu W, Yang Q (2015) Overexpression of potato miR482e enhanced plant sensitivity to Verticillium dahliae infection.