Heterologous expression of cyanobacterial PCS confers augmented arsenic and cadmium stress tolerance and higher artemisinin in Artemisia annua hairy roots

Abstract

The present study provides the first report of heterologous expression of phytochelatin synthase from Anabaena PCC 7120 ( anaPCS ) into the hairy roots of Artemisia annua . Transformed hairy roots of A. annua expressing anaPCS gene showed better tolerance to heavy metals, viz., arsenic (As) and cadmium (Cd) owing to 143 and 191% more As- and Cd-accumulation, respectively, as compared to normal roots with a bioconcentration factor (BCF) of 9.7 and 21.1 for As and Cd, respectively. Under As and Cd stresses, transformed hairy roots possessed significantly higher amounts of phytochelatins and thiols probably due to the presence of both AaPCS ( Artemisia annua PCS ) and anaPCS . In addition, artemisinin synthesis was also induced in transformed hairy roots under heavy metals stresses. In-silico analysis revealed the presence of conserved motifs in both AaPCS and anaPCS sequences as well as structural modelling of PCS functional domain was conducted. Interaction of AaPCS and anaPCS proteins with CdCl 2 and sodium arsenate gene ontology analysis gave insights to anaPCS functioning in transformed hairy roots of A. annua . The study provides transformed hairy roots of A. annua as an efficient tool for effective phytoremediation with added advantages of artemisinin extraction from hairy roots used for phytoremediation. Supplementary Information The online version contains supplementary material available at 10.1007/s11816-021-00682-5.

Bacteria – Plant Interaction: Transgenic Roots for Human Health

“…Fu et al (2021) detected that overexpression of blue light receptor AaCRY1 increased artemisinin content in transgenic plants. Heterologous expression of cyanobacterial PCS increased artemisinin content in A. annua hairy roots (Pandey et al, 2021b). LIS promoter activity for artemisinin synthesis was analyzed (Wang et al, 2014).…”

“…However, the level of synthesis under such conditions was lower than in the case of rol B gene use. Expression of β-glucosidase (Singh et al, 2016), HMG-CoA reductase gene (Aquil et al, 2009), cyanobacterial PCS (Pandey et al, 2021b), and AaWRKY1 (Han et al, 2014) affected artemisinin biosynthesis in transgenic plants and hairyroots.…”