Exploring aliphatic glucosinolates metabolism with knock outs: how to make Arabidopsis tastier to herbivores

Using transcriptional co-regulation analysis, we have recently identified several genes involved in glucosinolates metabolism. Myb28, a member of Myb subfamily 12, together with Myb29, 76, 51, 122 and 34, was identified as a regulator aliphatic glucosinolates, while Myb34 has been previously identified by others as a regulator of indolic glucosinolates and tryptophan metabolism. Plants lacking the transcription factor Myb28 or Myb29 have an altered transcription of biosynthetic genes as well as a different profile of aliphatic glucosinolates. We provide evidence that the double KO is completely lacking this class of secondary metabolites. Since the double mutant is devoid solely of aliphatic glucosinolate, their relevance to herbivory by larvae of the lepidopteran insect Mamestra brassicae could be tested. Plant damage correlated inversely to the levels of aliphatic glucosinolates observed in the different genotypes. We also isolated a mutant altered in the expression of a putative transporter for aliphatic glucosinolates and we expect a different distribution at the plant level with an accumulation in rosette leaves.