Arabidopsis acetolactate synthase

Haughn, G., Smith, J., Mazur, B. Sommerville, C. (1988). Transformation with a mutant Arabidopsis acetolactate synthase gene renders tobacco resistant to sulfonylurea herbicides. Molecular and General Genetics 211, 266-71. 

FIGURE 2 Amino acid conservation between acetolactate synthase genes. The numbers indicate amino acid residues. The first bar represents a comparison of the deduced amino acid sequences of ALS from tobacco and Arabidopsis-, the second bar represents a comparison between the amino acid sequences of the three E. coli ALS isozymes. Regions of conservation are shown in white. 

MoAs, such as, for example, acetolactate synthase (ALS), protoporphyrinogen oxidase (PPO), photosystem I, photosystem II or 5-enolpyruvylshikimi-3-phosphate-synthase (EPSPS). All expression profiles in the compendium are derived from Arabidopsis plants sprayed vith two different concentrations of the respective compounds and harvested 24 h after treatment. Analysis of the expression profiles by statistical methods like hierarchical clustering [14] revealed that the assumption was correct. The profiles of compounds representing the same MoA were much more similar to each other than to any profile derived from a compound with another MoA (Fig. 33.3). 

Saika H, Horita J, Taguchi-Shiobara F, Nonaka S, Ayako NY, Iwakami S, Hori K, Matsumoto T, Tanaka T, Itoh T, Yano M, Kaku K, Shimizu T, Toki S (2014) A novel rice cytochrome P450 gene, CY-P72A31, confers tolerance to acetolactate synthase-inhibiting herbicides in rice and Arabidopsis. Plant Physiol 156 1232-1240... 

Although only limited results are currently available, enzymes associated with amino acid biosynthesis in higher plants appear to be nuclear encoded. Consequently, transport into chloroplasts would be expected to be facilitated by the presence of an N-terminal transit peptide on the initial translation product. This appears to be the case with acetolactate synthase (19), which is nuclear encoded and localized in chloroplasts (Chaleff and Ray, 1984). Evidence for nucleotide sequences that could code for an N-terminal transit peptide composed of between 85 and 99 residues was obtained for the genes isolated from Arabidopsis and Nicotiana (Mazur et al, 1987). The absence of synthesis of iS-adenosylmethionine in plastids is further supported by the apparent lack of a nucleotide sequence coding for a transit peptide in an adenylatetransferase Arabidopsis gene (Peleman et al., 1989). 

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