Ethylene has an important role in regulating plant growth and development as well as responding to adversity stresses. The 1-aminocyclopropane-1-carboxylate synthase (ACS) is the rate-limiting enzyme for ethylene biosynthesis. However, the role of the ACS gene family in wheat has not been examined. In this study, we identified 12 ACS members in wheat. According to their position on the chromosome, we named them TaACS1-TaACS12, which were divided into four subfamilies, and members of the same subfamilies had similar gene structures and protein-conserved motifs. Evolutionary analysis showed that fragment replication was the main reason for the expansion of the TaACS gene family. The spatiotemporal expression specificity showed that most of the members had the highest expression in roots, and all ACS genes contained W box elements that were related to root development, which suggested that the ACS gene family might play an important role in root development. The results of the gene expression profile analysis under stress showed that ACS members could respond to a variety of stresses. Protein interaction prediction showed that there were four types of proteins that could interact with TaACS. We also obtained the targeting relationship between TaACS family members and miRNA. These results provided valuable information for determining the function of the wheat ACS gene, especially under stress.

Drought stress is an important factor that severely affects crop yield and quality. Autophagy has a crucial role in the responses to abiotic stresses. In this study, we explore TaNBR1 in response to drought stress. Expression of the TaNBR1 gene was strongly induced by NaCl, PEG, and abscisic acid treatments. The TaNBR1 protein is localized in the Golgi apparatus and autophagosome. Transgenic Arabidopsis plants overexpressing TaNBR1 exhibited reduced drought tolerance. When subjected to drought stress, compared to the wild-type (WT) lines, the transgenic overexpressing TaNBR1 plants had a lower seed germination rate, relative water content, proline content, and reduced accumulation of antioxidant enzymes, i.e., superoxide dismutase, peroxidase, and catalase, as well as higher chlorophyll losses, malondialdehyde contents, and water loss. The transgenic plants overexpressing TaNBR1 produced much shorter roots in response to mannitol stress, in comparison to the WT plants, and they exhibited greater sensitivity to abscisic acid treatment. The expression levels of the genes related to stress in the transgenic plants were affected in response to drought stress. Our results indicate that TaNBR1 negatively regulates drought stress responses by affecting the expression of stress-related genes in Arabidopsis.

Schizaphis graminum is the most important pest of wheat, and its feeding harm not only affects photosynthesis but also causes diseases, posing a serious threat to wheat production. We measured the contact killing and fumigation activities, population changes, enzyme activities, and nanoemulsion physicochemical property of Eupatorium fortune essential oil (EFEO) and pyrethrin against S. graminum and its natural enemy (Harmonia axyridis). Toxic effects of EFEO and pyrethrin increased with increasing concentration. After 24 h of contact killing, the LD₅₀ of S. graminum were 9.23 and 0.02 μg/head, respectively. Harmonia axyridis were 36.71 and 0.07 μg/head. The fumigation of EFEO LD₅₀ on S. graminum was 9.779 mg/L (y = 2.88x − 2.852). EFEO contains 28 chemical components, including l-Caryophyllene, Lily aldehyde, α-Terpineol, and Cineole. EFEO LD₅₀ significantly reduced the adult longevity, nymph production, and nymph production duration of the F0 S. graminum, while there were no significant differences in various parameters of offspring. The activity of acetylcholinesterase, glutathione-S-transferase, and carboxylesterase is significantly affected. The population decline rate of EFEO nanoemulsion is significantly higher than that of EFEO. This research aims to clarify the toxic effect of EFEO on S. graminum, providing a scientific basis for developing new plant essential oil preparations and nano preparations.