## 1 Introduction  
Amino acids present in grapes serve as a nitrogen source for yeasts during alcoholic fermentation [1]. Amino acids in grapes are precursors of volatile compounds, such as leucine, valine, isoleucine, and phenylalanine [2]; and the branched-chain amino acids (valine, leucine, and isoleucine), aromatic amino acids (phenylalanine, tyrosine, and tryptophan), and methionine in grapes can be converted into \(\alpha\)-ketoads and metabolized into higher alcohols and higher acids in yeast cells through the Ehrlich pathway [2,3]. These compounds can be further metabolized into alcohol esters and acetates [3]. These fermentative volatile compounds account for approximately 50% of the total volatile concentration in wines [4]. Thus, amino acid profiles in grapes affect fermentation development and have an important role in the production of volatile compositions [2]. Many previous studies have reported how changes in grape amino acid content can affect wine volatile composition [1; 5; 6] because phenylalanine, leucine, isoleucine, valine, tyrosine, and methionine seem to be precursors of volatile compounds (2-phenylethylanol, 3-methyl-1-butanol, 2-methyl-1-butanol, isobutanol, tyrosol, and methionol, respectively). The addition of branched-chain amino acids (such as valine, leucine, and isoleucine) during fermentation increases higher alcohol production. In comparison, adding phenylalanine increases the concentrations of 2-phenylethylanol, 2-phenylethyll acetate, and ethyl esters in wine [7]. Therefore, future work is needed to reveal the relationship between amino acids and aromas in grapes and wines. Amino acids and volatile compositions in grapes and wines are affected by many factors, including viticultural practices, climate conditions, and nitrogen fertilization [7; 8; 9; 10]. Recently, great research effort has been devoted to assessing changes in the amino acids and aroma components in grapes and wines after different treatments. [PERSON] et al. [8] reported that the application of aqueous extracts of vine-shoot waste could enhance the amino acid content of wine. They also reported that a higher amino acid concentration in must resulted in higher consumption during alcoholic fermentation, and the resultant wines have a lower concentration of amino acids. [PERSON] et al. [9] reported that irrigation alters the concentration of methionine in musts, and the vintage is closely related to the amino acid content in must.  
Grape is an important fruit with economic and nutritional value and is cultivated in China. Northwest China is the main grape cultivation area, especially Ningxia, Xinjiang, and Gansu. However, the shortage of fresh water resources restricts the development of the grape industry in China. Regulated deficit irrigation (RDI) can save water and improve crop quality [11; 12; 13], alter grape and wine flavors and phenolic compounds, and plays an important role in improving vine canopy shapes, vigorous vines, and canopy microclimates [14; 15; 16; 17; 18]. However, few reports exist on the effect of RDI on amino acid contents and their derived volatiles in grapes and wines. Exploring whether this influence is positive or negative could provide a theoretical foundation for producing high-quality grapes and wines.  
Consequently, the aim of this work was to gain insight on the effect of RDI grapevine treatment on the amino acid composition in grapes and wine and fermentative volatile compounds in wine since previous studies suggest that using RDI as a strategy to promote efficient water use in agriculture alters metabolites in grapes. The relationship between amino acids and the fermentative volatile compositions in wine was also elucidated using three different RDI strategies.