These authors contributed equally to this work.
The R2R3-MYB transcription factor HAG1/MYB28 is a regulator of methionine-derived glucosinolate biosynthesis in Arabidopsis thaliana
Article first published online: 23 MAY 2007
The Plant Journal
Volume 51, Issue 2, pages 247–261, July 2007
How to Cite
Gigolashvili, T., Yatusevich, R., Berger, B., Müller, C. and Flügge, U.-I. (2007), The R2R3-MYB transcription factor HAG1/MYB28 is a regulator of methionine-derived glucosinolate biosynthesis in Arabidopsis thaliana. The Plant Journal, 51: 247–261. doi: 10.1111/j.1365-313X.2007.03133.x
- Issue published online: 8 JUN 2007
- Article first published online: 23 MAY 2007
- Received 19 January 2007; revised 12 March 2007; accepted 21 March 2007.
- biotic stress;
- glucose-responsive genes;
- MYB transcription factors
Methionine-derived glucosinolates belong to a class of plant secondary metabolites that serve as chemoprotective compounds in plant biotic defense reactions and also exhibit strong anticancerogenic properties beneficial to human health. In a screen for the trans-activation potential of various transcription factors toward glucosinolate biosynthetic genes, we could identify the HAG1 (HIGH ALIPHATIC GLUCOSINOLATE 1, also referred to as MYB28) gene as a positive regulator of aliphatic methionine-derived glucosinolates. The content of aliphatic glucosinolates as well as transcript levels of aliphatic glucosinolate biosynthetic genes were elevated in gain-of-function mutants and decreased in HAG1 RNAi knock-down mutants. ProHAG1:GUS expression analysis revealed strong HAG1 promoter activity in generative organs and mature leaves of A. thaliana plants, the main sites of accumulation of aliphatic glucosinolates. Mechanical stimuli such as touch or wounding transiently induced HAG1/MYB28 expression in inflorescences of flowering plants, and HAG1/MYB28 over-expression reduced insect performance as revealed by weight gain assays with the generalist lepidopteran herbivore Spodoptera exigua. Expression of HAG1/MYB28 was significantly induced by glucose, indicating a novel transcriptional regulatory mechanism for the integration of carbohydrate availability upon biotic challenge. We hypothesize that HAG1/MYB28 is a novel regulator of aliphatic glucosinolate biosynthesis that controls the response to biotic challenges.