Targeted silencing of genes in polyploids: lessons learned from Brassica juncea-glucosinolate system
Intron-spliced hairpin RNAi construct targeting the exonic region of BjuMYB28 driven by the native promoter is the best suited strategy for developing viable low glucosinolate lines in polyploid Brassica juncea.
Targeted silencing of specific homolog(s) of a multigene family in polyploids through RNA interference (RNAi) is a challenging effort. Indian oilseed mustard (Brassica juncea), a natural allotetraploid, is expected to have 4–6 copies of every Arabidopsis gene ortholog. In the current study, we have attempted to establish the best gene silencing system suitable for BjuMYB28, a transcription factor gene, with the objective of developing low seed glucosinolate lines in B. juncea. After comparing multiple combinations of BjuMYB28 gene homologs, promoters, target regions (exon and 3′ UTR) and silencing strategies (RNAi and antisense), we suggest that the intron-spliced hairpin RNAi construct targeting the specific exonic region of the BjuMYB28 gene under the control of native promoter, whose peak activity synchronises with the highest glucosinolate accumulation phase of the plant, is the best suited strategy for developing viable low glucosinolate lines in polyploid B. juncea.
KeywordsBrassica Glucosinolates BjuMYB28 Gene-silencing
Small interfering RNA
Research was supported by project grants (BT/PR10268/27/81/2007 and BT/PR2171/AGR/36/687/2011) from DBT (India) to NCB. RA was supported from JRF of CSIR (India) and Short Term Research Fellowship of NIPGR (New Delhi).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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