Methyl jasmonate (MeJA) elicitation is an efficient strategy to induce and

Methyl jasmonate (MeJA) elicitation is an efficient strategy to induce and enhance synthesis of the anticancer agent paclitaxel (Taxol?) in cell suspension cultures; however concurrent decreases in growth are often observed which is problematic for large scale bioprocessing. increase in G0/G1 phase cells and decreased the number of actively dividing cells. Through a combination of deep sequencing and gene expression analyses the expression status of cell cycle-associated genes correlated with observations at the BAY57-1293 culture level. Results Hoxc8 from this study provide valuable insight into the mechanisms governing MeJA perception and subsequent events leading to repression of cell growth. species and cell cultures (Bonfill et al. 2006 Ketchum et al. 1999 Yukimune et al. 1996). Paclitaxel is widely used for treatment of breast ovarian and lung cancers as well as AIDS-related Kaposi’s sarcoma and is being investigated for use in the treatment of neurological disorders and in post-surgery heart patients (Vongpaseuth and Roberts 2007). Paclitaxel titers of up to 900 mg/L have been achieved in industrial environments using a combination of MeJA elicitation and cell culture optimization strategies (Bringi et al. 2007). Increased secondary metabolite accumulation upon MeJA elicitation is often accompanied with concurrent decreases in culture growth (Kim et al. 2005) Thanh et al. 2005 Zhang and Turner 2008 Sun et al. 2013). MeJA has been shown to broadly induce defense responses and secondary metabolism in plants (Farmer and Ryan 1990 Reymond and Farmer 1998 Seo et al. 2001) which diverts carbon resource allocation from primary metabolism (Logemann et al. 1995 Pauwels et al. 2009). Recent studies indicate that MeJA-mediated growth inhibition is associated with perturbations in mitochondrial membrane integrity along with decreases in the biosynthesis of ATP (Ruiz-May et al. 2011) and proteins related to energy metabolism (Cho et al. 2007). At a mechanistic level MeJA has demonstrated an inhibitory effect on growth at the level of the cell cycle (Pauwels et al. 2008 Swiatek et al. 2002). Most studies to understand the effect of jasmonates on the cell cycle have been done in angiosperms such as and tobacco BY-2 cell suspension cultures (Pauwels et al. 2008 Swiatek et al. 2002). Exogenously applied MeJA blocks the G1/S and G2/M transitions in the cell cycle of cultured tobacco BY-2 cells (Swiatek et BAY57-1293 al. 2002). Micromolar concentrations of MeJA added to suspension cultures repressed the activation of M phase genes arresting cells in G2 phase (Pauwels et al. 2008). Genomic information and established protocols for synchronizing cell cultures (Kumagai-Sano et al. 2006 Menges et al. 2002) to understand cell cycle events are readily available for these plant BAY57-1293 species facilitating mechanistic studies. In contrast gymnosperms such as have not been as well studied with regard to cell cycle progression and the mechanism of MeJA-repressed growth. While a number of studies have reported increased taxane biosynthetic pathway gene BAY57-1293 products upon MeJA elicitation (Jennewein et al. 2004 Nims et al. 2006 Patil et al. 2012 Li et al. 2012) there have been few reports regarding the role of MeJA on growth inhibition and cell cycle progression in cultures (Kim et al. BAY57-1293 2005 Naill and Roberts 2005 In the present study we investigate the influence of MeJA on both cell growth and viability of cells in batch culture. The effect of MeJA on cell cycle progression was determined using asynchronous cells. Actively dividing cells were quantified and cell cycle kinetics were determined by cumulative and pulse-labeling using 5-ethynyl-2’-deoxyuridine (EdU) a nucleoside analog of thymidine. Recently obtained 454 and Illumina transcriptome sequencing data for both MeJA-elicited and mock-elicited cultures were used to obtain the expression status of cell cycle-associated genes in the asynchronous cultured cells. There is currently minimal sequence information on cell cycle regulated genes derived from this division of the plant kingdom (Li et al. 2012 Sun et al. 2013) and these studies provide the first insight into cell cycle control upon elicitation with MeJA. Because the mechanism of action of MeJA has not been investigated to date for gymnosperms such as growth occurs at the level of cell cycle providing important.