Wheat plays a crucial role in global food security. However, drought stress severely restricts its growth and development, and drought during the seedling stage significantly affects its organogenesis, thereby affecting yield. To study wheat drought tolerance mechanisms at the seedling stage and to explore drought tolerance gene resources, this study focused on the drought-tolerant wheat variety Bainong 207 and performed RNA-Seq and metabolome sequencing on leaves collected at the three-leaf stage under drought stress conditions. Drought stress significantly altered the expression of 12,930 genes and 2544 metabolites in wheat seedlings. Through bioinformatics methods such as O2PLS-DA, a gene–metabolite correlation network was constructed, and key regulatory genes within this network were subsequently identified. The results identified the important gene module MEbrown and metabolite module Meta6 and finally screened 20 transcription factors that are closely related to drought response. These transcription factors were predicted to be able to combine and regulate the expression of six key genes, which together help the variety to improve drought tolerance under drought stress conditions by regulating reactive oxygen species metabolism, maintaining intracellular redox homeostasis, promoting wax biosynthesis, enhancing the osmotic stress response, and regulating abscisic acid response.

Cysteine (Cys) is an essential chiral amino acid that exists in L- and D-forms. L-Cys is the predominant natural enantiomer and plays critical roles in numerous biological processes in plants and animals, while D-Cys occurs in extremely low abundance, rendering its detection challenging and leaving its functions poorly understood. To address this, we designed two enantioselective fluorescent probes, (S)-D3 and (R)-D3, derived from chiral binaphthol. Without requiring metal ions, (S)-D3 selectively binds and produces strong fluorescence enhancement only with D-Cys, whereas (R)-D3 responds specifically to L-Cys. Both probes exhibit excellent selectivity, showing negligible response to other amino acids. The probes were successfully employed for the analysis of Cys enantiomers in wheat, fluorescence monitoring of the cysteine thioetherification reaction through distinct fluorescence changes with (R)-D3, and real-time tracking of L- to D-Cys configurational inversion, where the two probes displayed symmetric, mirror-image fluorescence signals, enabling mutual cross-validation and dynamic observation of enantiomer interconversion.