Molecular Cloning and Characterization of Two 9-Lipoxygenase Genes from Taxus chinensis

Abstract

Plant lipoxygenases (LOXs) are functionally diverse class of dioxygenases involved in multiple physiological processes such as plant growth, biotic and abiotic stress responses, and secondary metabolite accumulation. In this paper, two LOX genes, TcLOX1 and TcLOX2, were cloned from Taxus chinensis cells. Multiple alignment of the deduced amino acid sequences with those of other plants demonstrated the putative LH2/PLAT domain, lipoxygenase iron-binding catalytic domain, lipoxygenase_1 and lipoxygenase_2 signature sequences. Phylogenetic analysis suggested that TcLOX1 and TcLOX2 putative proteins are most probably 9-LOXs, and shared the highest identity with the tea plant CsLOX1 and Picea sitchensis LOX genes, respectively. Semiquantitative RT-PCR analysis showed that TcLOX1 was preferentially expressed in stem and root, while TcLOX2 was preferentially expressed in root. Real-time quantitative PCR analysis showed that a strong upregulation of TcLOX1 was observed in response to methyl jasmonate and abscisic acid (ABA), while TcLOX2 was strongly upregulated by ABA. However, TcLOX1 and TcLOX2 were nearly not responding to salicylic acid. These data suggest both TcLOX1 and TcLOX2 play an important role in T. chinensis, and they are required in different physiological processes involved in different plant signals in vivo.

Comprehensive Genomic Characterization and Expression Analysis of the Lipoxygenase Gene Family in Watermelon under Hormonal Treatments

“…However, the 9-LOXs had V/H/L in the corresponding position instead ( Figure S2). The conserved V residue associated with 9-LOX activity is a characteristic of LOX enzymes, while some 9-LOXs possess no V residue at the position [37][38][39]. In addition, the analysis of conserved motif distribution and exon-intron arrangement further supported the phylogenetic results.…”

Paclitaxel production and PAL activity in hairy root cultures of Taxus x media var. Hicksii carrying a taxadiene synthase transgene elicited with nitric oxide and methyl jasmonate

“…LOX activity has been positively correlated with paclitaxel accumulation in elicited T. chinensis cells (Huang et al 2005;Wang and Wu 2005). Moreover, Li et al (2012) observed strong up-regulation of the TcLOX1 LOX gene, cloned from T. chinensis cells and preferentially expressed in stems and roots, in response to MJ elicitation.…”

The effects of putrescine are partly overlapping with osmotic stress processes in wheat

“…In the present study a bifunctional inhibitor/lipid-transfer protein/seed storage 2S albumin superfamily protein (Dir1) [56] and PLAT/LH2 domain-containing lipoxygenase have been upregulated not only under osmotic stress, but after PUT pre-treatment, while the highest induction was found after PUT pre-treated + PEG treatment. The PLAT/LH2 domain-containing lipoxygenase also has a role in plant signalling, as it was reported to be induced by ABA, SA, jasmonate or wounding [57].…”