The Sugars Will Eventually be Exported Transporter (SWEET) gene family, identified as sugar transporters, has been demonstrated to play key roles in phloem loading, grain filling, pollen nutrition, and plant-pathogen interactions.  To date, the study of SWEET genes in response to abiotic stress is very limited.  In this study, we performed a genome-wide identification of the SWEET gene family in wheat and examined their expression profiles under mutiple abiotic stresses.  We identified a total of 105 wheat SWEET genes, and phylogenic analysis revealed that they fall into five clades, with clade V specific to wheat and its closely related species.  Of the 105 wheat SWEET genes, 59% exhibited significant expression changes after stress treatments, including drought, heat, heat combined with drought, and salt stresses, and more up-regulated genes were found in response to drought and salt stresses.  Further hierarchical clustering analysis revealed that SWEET genes exhibited differential expression patterns in response to different stress treatments or in different wheat cultivars.  Moreover, different phylogenetic clades also showed distinct response to abiotic stress treatments.  Finally, we found that homoeologous SWEET genes from different wheat subgenomes exhibited differential expression patterns in response to different abiotic stress treatments.  The genome-wide analysis revealed the great expansion of SWEET gene family in wheat and their wide participation in abiotic stress response.  The expression partitioning of SWEET homoeologs under abiotic stress conditions may confer greater flexibility for hexaploid wheat to adapt to ever changing environments.

During winter wheat production, aphids need to be controlled with pesticides for the entire growth period.  Controlled-release technology has been regarded as an alternative method for the improvement of pesticide efficiency.  This study investigated two types of imidacloprid controlled-release granule (CR-GR): 2% imidacloprid CR-GR and 0.2% imidacloprid pesticide-fertilizer controlled-release granule (PF-CR-GR) when wheat was sown in winter.  The release performance, utilization rate, terminal residues in edible parts, control effect on aphids, and achieved winter wheat yield were evaluated for both laboratory experiments and field application.  Imidacloprid PF-CR-GR released more quickly in aqueous medium than CR-GR because of its good water solubility.  After CR-GR treatments, the concentrations in wheat roots and soil were similar throughout the entire sampling period, and the concentrations in shoots were about 10–20% of those in roots.  Imidacloprid was better absorbed when CR-GR was used as root treatment, compared with foliar treatment.  Field application showed that imidacloprid CR-GR and PF-CR-GR controlled aphids throughout the entire growth period of winter wheat and improved the wheat yield.  These findings identified application of imidacloprid CR-GR and PF-CR-GR on winter wheat as an effective way to enhance the pesticide utilization rate and ensure adequate yield.  This paper provides a theoretical basis for the scientific use of pesticides and guides scientific pesticide application.