Feeding behaviour of generalist pests on Brassica juncea: implication for manipulation of glucosinolate biosynthesis pathway for enhanced resistance.
Differential accumulation of plant defence metabolites has been suggested to have important ecological consequence in the context of plant-insect interactions. Feeding of generalist pests on Brassica juncea showed a distinct pattern with selective exclusion of leaf margins which are high in glucosinolates. Molecular basis of this differential accumulation of glucosinolates could be explained based on differential expression profile of BjuMYB28 homologues, the major biosynthetic regulators of aliphatic glucosinolates, as evident from quantitative real-time PCR and promoter:GUS fusion studies in allotetraploid B. juncea. Constitutive overexpression of selected BjuMYB28 homologues enhanced accumulation of aliphatic glucosinolates in B. juncea. Performance of two generalist pests, Helicoverpa armigera and Spodoptera litura larvae, on transgenic B. juncea plants were poor compared to wild-type plants in a no-choice experiment. Correlation coefficient analysis suggested that weight gain of H. armigera larvae was negatively correlated with gluconapin (GNA) and glucobrassicanapin (GBN), whereas that of S. litura larvae was negatively correlated with GNA, GBN and sinigrin (SIN). Our study explains the significance and possible molecular basis of differential distribution of glucosinolates in B. juncea leaves and shows the potential of overexpressing BjuMYB28 for enhanced resistance of Brassica crops against the tested generalist pests.
['Kumar|Pawan|P|', 'Augustine|Rehna|R|', 'Singh|Amarjeet Kumar|AK|', 'Bisht|Naveen C|NC|http://orcid.org/0000-0001-7817-2193']
D000818:Animals D001681:Biological Assay D053898:Biosynthetic Pathways D005247:Feeding Behavior D020869:Gene Expression Profiling D018506:Gene Expression Regulation, Plant D005961:Glucosinolates D007313:Insecta D009149:Mustard Plant D009928:Organ Specificity D018515:Plant Leaves D030821:Plants, Genetically Modified D018411:Spodoptera
generalist pest plant defence MYB28