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Branched-chain amino acid biosynthesis inhibitors: herbicide efficacy is associated with an induced carbon-nitrogen imbalance
- Source :
- Academica-e: Repositorio Institucional de la Universidad Pública de Navarra, Universidad Pública de Navarra, Academica-e. Repositorio Institucional de la Universidad Pública de Navarra, instname
- Publication Year :
- 2012
-
Abstract
- Acetolactate synthase (ALS; EC 4.1.3.18) and ketol-acid reductoisomerase (KARI; EC 1.1.1.86) are two consecutive enzymes in the biosynthesis of branched-chain amino acids. Several commercial herbicides inhibit ALS as their primary site of action. KARI has also attracted attention as a potential target for herbicides. Although potent and selective inhibitors of KARI have been discovered, these inhibitors display less herbicidal activity than ALS-inhibiting herbicides. To obtain a better understanding of these findings, we have compared the physiological effects induced in pea plants after KARI or ALS inhibition. Although, both types of inhibitors induce growth arrest and photosynthesis inhibition, plant death occurs more rapidly under ALS inhibition than KARI inhibition. Carbohydrates accumulated in the leaves and roots following treatments with both inhibitors. The carbohydrate accumulation in the leaves occurred as a consequence of a decrease in sink strength. In contrast, the free amino acid content was only affected through ALS inhibition. These results indicate that although KARI and ALS inhibition block the same biosynthetic pathway and exert common effects on carbon metabolism, nitrogen metabolism is more affected via ALS than KARI inhibition. Thus, metabolic alterations in nitrogen metabolism induced through ALS inhibitors might contribute to the increased efficacy of these chemicals as herbicides. M. Igal received a grant from the Public University of Navarre. A. Zulet and M. Gil-Monreal receive funding through fellowships from the Spanish Ministry of Education and the Public University of Navarre, respectively. This work was financially supported through grants from the Spanish Ministry of Education and Science (AGL-2010-18621).
- Subjects :
- Adenosine
Physiology
Nitrogen
Branched-chain amino acid
Ketol-Acid Reductoisomerase
Quinic Acid
Plant Science
Carbohydrate metabolism
Plant Roots
chemistry.chemical_compound
Biosynthesis
Photosynthesis
Mode of action
chemistry.chemical_classification
Acetolactate synthase
Ketol-acid reductoisomerase
biology
Dose-Response Relationship, Drug
Herbicides
Peas
Plant Transpiration
Carbohydrate
Carbon
Amino acid
Plant Leaves
Acetolactate Synthase
Enzyme
chemistry
Biochemistry
biology.protein
Lactates
Carbohydrate Metabolism
Herbicide
Agronomy and Crop Science
Amino Acids, Branched-Chain
Plant Shoots
Subjects
Details
- ISSN :
- 16181328
- Volume :
- 170
- Issue :
- 9
- Database :
- OpenAIRE
- Journal :
- Journal of plant physiology
- Accession number :
- edsair.doi.dedup.....596348628dbcea887782ed16542f8511