# Effect of Mechanical Damage in Green-Making Process on Aroma of Rougui Tea
## 3 Results
### Analysis of DEGs and DEPs Related to Biosynthesis of Aroma Components  
In addition to the changes in the main aroma components of the samples and the KEGG pathways enriched by differential genes and proteins, we further investigated the expression patterns of key genes and proteins related to the aroma synthesis of RGT (\(\alpha\)-linolenic acid metabolism, terpenoid biosynthesis and the phenylalanine metabolism pathway). The expression of the differential genes and proteins related to the \(\alpha\)-linolenic acid metabolism pathway detected in this research between samples is shown in Figure 5A. The upregulation of the lipoxygenase (LOX) gene was more obvious in the CK group. In the process of green-making, the LOX gene showed a trend of first increasing and then decreasing and reached the lowest level at the end of green-making, which was essentially consistent with previous studies [39]. Two coding proteins (TEA011765.1 and TEA012289.1) were detected in the proteome data. LOX was upregulated about one to two times at the end of green-making, and the upregulated range was higher in the CK group. Some studies have shown that mechanical injury, tissue injury, drought and other stress conditions can improve the transcription and expression of the enzyme genes and improve the enzymes' activity [40; 41; 42]. LOX is a key rate-limiting enzyme in the alpha-linolenic acid metabolic pathway, and this enzyme gene is induced under mechanical injury and dehydration and can promote the synthesis of related metabolites [43; 44]. Hydroperoxide lyase (HPL) and alcohol dehydrogenase (ADH) catalyze the formation of green leaf volatiles (GLVs). Studies have shown that when plants are subjected to abiotic stresses such as mechanical injury, the expression levels of the HPL gene and protein are increased, and the expression levels of the HPL gene and protein are improved through ADH and alcohol acyltransferases (AAT), which are further transformed into corresponding alcohols, esters and other volatiles to produce defense reactions [45; 46]. The HPL gene's expression was significantly increased in the CK group (\(p<0.05\)), while the ADH gene's expression was generally higher at the end of green-making, in which TEA029320.1 was upregulated to the maximum value, while no relevant protein data were detected by proteomic analysis. Another branch of \(\alpha\)-linolenic acid metabolism, the allene oxide synthase (AOS) pathway, is involved in the synthesis of jasmonic acid and its derivatives, and multiple genes encoding the same enzyme were detected in this branch of the pathway, but their expression was not completely consistent in all samples. The expression of the AOS protein was significantly upregulated at the end of green-making and spreading, while it was downregulated in the transcriptome data (\(p<0.05\)). The allene oxide cyclase (AOC) gene increased at first and then decreased in the process of green-making, and most of the coding genes decreased after the seventh shaking step, yielding slightly higher levels than in the CK group. Six 12-oxophytotienoic acid reductase (OPR) genes were detected, among which TEA025907.1, TEA026806.1 and TEA029800.1 were highly expressed in LY compared to CK. One protein's expression trend was consistent with the transcriptome data, while the other protein was inconsistent. It was found that an OPCL gene was highly expressed in SY and was the highest at the end of green-making, but the expression trend of its coding protein showedthe opposite pattern. Acyl-CoA oxidase (ACX) is the rate-limiting enzyme of fatty acid \(\beta\)-oxidation, and its expression increased during the manufacturing process. Two proteins (TEA017099.1 and TEA019216.1) were expressed at the highest levels at the end of green-making. The expression of the enoyl-CoA hydratase (MFP2) and acetyl-CoA acyltransferase (ACAA) genes was significantly upregulated under continuous mechanical injury and dehydration, while the expression trends of the two coding proteins were the opposite to those in the transcriptional group (\(p<0.05\)).