Deepti M. Nambiar

Deepti Nambiar - 10/11/2020

To study functional divergence of glucosinolates transporter gene family in Brassica juncea

10 November 2020

Online

Deepti M. Nambiar (National Institute of Plant Genome Research (JNU), India)

Glucosinolates (GSLs) are Brassicales specific defence related secondary metabolites which are antinutritive/ anticancerous. In oilseed crops like Brassica juncea, seed GSL reduction without affecting biosynthesis, is thus desirable. In this context GTR transporters, which play a role in GSL source to sink (seed) translocation, are potential targets. Our objective was molecular and functional characterization of B. juncea GTR homologs, a prerequisite for transport engineering. Transgenic cotton cell lines (CCL-1) expressing Brassica and Arabidopsis GTRs were generated and this novel assay system used for kinetic analysis of GTRs. It was ascertained that all investigated GTRs were functional, conformed to Michaelis-Menten kinetics and had affinity for aliphatic and aromatic GSLs with µmolar Km values. For in planta functional characterization, complementation lines were generated from Arabidopsis gtr1gtr2 double mutants. These mutants synthesize wild type levels of 14 different GSLs but lack seed GSL. Complementation with Brassica and Arabidopsis GTRs restored all/some GSLs in seeds, thus revealing the broad substrate specificities of GTRs.  

 

Contact: marie-jeanne.sellier@inrae.fr

Modification date : 06 December 2023 | Publication date : 28 November 2023