Discovery of a DFR gene that controls anthocyanin accumulation in the spiny Solanum group: roles of a natural promoter variant and alternative splicing.

Anthocyanins are important pigments that impart color in plants. In Solanum, different species display various fruit or flower colors due to varying degrees of anthocyanin accumulation. Here we identified two anthocyanin-free mutants from an ethylmethane sulfonate-induced mutant library and naturally occurring mutants in Solanum melongena, with mutations in the 5' splicing site of the second intron of dihydroflavonol-4-reductase (DFR) - leading to altered splicing. Further study revealed that alternative splicing of the second intron was closely related to anthocyanin accumulation in 17 accessions from three cultivated species: S. melongena, Solanum macrocarpon and Solanum aethiopicum, and their wild related species. Analysis of natural variations of DFR, using an expanded population including 282 accessions belonging to the spiny Solanum group, identified a single-nucleotide polymorphism in the MYB recognition site in the promoter region, which causes differential expression of DFR and affects anthocyanin accumulation in fruits of the detected accessions. Our study suggests that, owing to years of domestication, the natural variation in the DFR promoter region and the alternative splicing of the DFR gene account for altered anthocyanin accumulation during spiny Solanum domestication.

Adsorption Properties of Diatomite Minerals on Glyceryl Monostearate for Antifogging of the Plastic Film.

Adding an appropriate amount and the stable precipitation of surfactant on the inner surface of agricultural plastic greenhouse films can prevent the formation of water droplets on the inner surface of the film to reduce its harmful effects in the process of plant cultivation and production. In this work, for the stable precipitation of the surfactant glycerol monostearate, diatomite minerals from three origins in China were compared through structural analysis and adsorption performance. The effects of acid treatments and alkali treatments on the mineral structure were studied, and the adsorption mechanism of glycerol monostearate was further investigated. The results show that the structural characteristics of Jilin diatomite are more suitable as adsorbents for glyceryl monostearate adsorption. Because diatomite is resistant to acids but not alkalis, when diatomite is treated with an alkali, impurities on its surface can be removed and the hydroxyl group and specific surface area can be greatly increased. The adsorption capacity of glycerol stearate was increased to 218.4 mg/g, or 32.08%, over its pretreatment level. The results show that this is mainly the result of physical adsorption caused by van der Waals force imbalance and chemisorption caused by a small number of hydrogen bonds. In addition, the dripping performance of this composite dripping film with mineral diatomite was better than that of the commercial dripping film, which provided a theoretical basis for efficient mineral slow-release drip irrigation composite film.