*2.3. VOCs and Plants Dormancy*

Dormancy is a physiological state in which plants respond to stress [83]. DADS is considered as main allelochemical of VOCs in garlic [53]. Hosoki et al. reported that the sulfur-containing compounds from garlic VOCs could break the bud dormancy in some corms, tubers, and ornamental trees [84,85]. Kubota et al. found that exposure to volatile diallyl disulfides and trisulfides was the most effective treatment to promote the bud break of single-bud cuttings of "Kyoho" (*Vitis vinifera* × *labruscana Bailey*) [86]. So, the allelochemicals in garlic that break the dormancy of vine buds are sulfur compounds, particularly DADS. In addition to DADS, more and more studies can prove that VOCs can affect plant dormancy. In a recent study, Shukla et al. studied the breaking dormancy of potato tubers effects on 20 essential oils from medicinal and aromatic plants [87]. The essential oils could induce or inhibit the sprouting process of potato tubers by altering the accumulation of reducing sugars, ethylene production, and expression of genes, thereby affecting the dormancy of plants [87]. Besides, eugenol from clove essential oil and carvone from caraway and dill essential oils have been reported to inhibit potato tubers sprouting [88–90]. The results showed that the essential oils of lemon grass and clove were the most effective VOCs for breaking dormancy and inducing germination of potato tubers. The oils of palmarosa and ajwain inhibited the sprout of potato tubers [87]. Owolabi et al. found the essential oils of *Lippia multiflora*, *Cymbopogon citratus*, and *Zingiber officinale* could control potato tubers dormancy [91]. They are suitable for application as sprout suppressants. At present, there are few studies on the effects of VOCs on plant dormancy, and the specific mechanism of action needs to be studied in the future.
