## 1 Introduction  
Plants from the genus _Cymbopogon_ (Panicoideae subfamily of the Poaceae, or grass family) are perennial medicinal herbs and aromatic plants with more than 55 species distributed in tropical and subtropical countries. They are native to India, Sri Lanka, and Malaysia. In Mexico, the best-known and most widespread species is _Cymbopogon citatus_, also known as lemongrass. _Cymbopogon_ species produce essential oil (EO), conferring these plants their characteristic fragrance. EO mainly contains monoterpenes and sesquiterpenes as bioactive compounds (BC). Citral, nerol, geraniol, citronellal, linalool, limonene, and geranyl acetate, correspond to the first class. In comparison, \(\beta\)-caryophyllene and humucle correspond to sesquiterpenes [1]. Because of its aroma, which is similar to the lime fruit, the EO is of great interest in the flavor, fragrances, perfumery, cosmetics, soaps, and pharmaceutical industries [1]. The EO constituents of the genus Cymbopogon are bioactive compounds with several tested biological activities such as antioxidant, antiinflammatory, antifungal, antibacterial, and anticancer properties with potential use in medicine [2]. Different types of cancer are among the most common leading causes of death worldwide [3,4]. Citral has shown anticancer activity in various human cancer cell lines, including cervical [4] and stomach [5] cancer cell lines. At the same time, different studies have shown the activity of geraniol against lung, prostate, bowel, liver, colorectal, kidney, and skin cancer [6]. Other studies also have reported that limonene prevents the progression of mammary and liver cancers [7]. Likewise, geranyl acetate has potent antifungal and anti-inflammatory activities [8]. [PERSON] et al. [9] also evaluated nerol derivatives activity against cancer cell lines. In addition, \(\beta\)-caryophyllene also exhibited antiproliferative effects against colorectal [10] breast, pancreas, lymphoma, and melanoma cancer cells [11]. Today, medicinal plants are of great importance in the health industry, and almost 25% of modern medicines are obtained or derived from natural sources [12]. The use of biotechnologies based on plant cell cultures is more promising, sustainable, and environmentally friendly than traditional cultivation of medicinal plants, allowing better control of the quality and higher yields of the desired secondary metabolites [12]. Different studies deal with diverse ways to improve EO productivity and yield, as well as selection of high-yielding genotypes of _Cympopgon_ species [13, 14, 15, 16, 17]. It is also well known that water stress significantly affects plant growth and development and might induce a high accumulation of secondary metabolites. As part of the water stress response, plants make morphologic changes, intracellular osmotic adjustments increasing the sugar content in roots and leaves and solute accumulation. Plants also express antioxidant defense mechanisms and enhance the content of monoterpenes and sesquiterpenes [18]. The EO of some herbs and medicinal plants is reported to be increased by water stress. For instance, the content of monoterpenes in _Salvia officinalis_ is increased by drought stress [19]. In _Artemisia annua_, various volatiles are also increased by water deficit treatment [20]. In addition to environmental conditions, exogenous application of plant growth regulators influences terpene biosynthesis and the EO composition and production in aromatic plants [15]. Previous studies reported using plant growth regulators to enhance the productivity and yield of lemongrass EO, such as triacontanol [14], and more specifically, the use of exogenous cytokins (CKs) to enhance monoterpene biosynthesis. CKs are a group of plant growth regulators that play an essential role during the cell cycle, influencing plant growth and development [21]. Natural plant (isopropoid) CKs are synthesized through the mevalonic acid and MEP pathways.