Acetolactate synthase inhibitors resistance

Gaeddert, J.W., D.E. Peterson, and M.J. Horak (1997). Control and cross-resistance of an acetolactate synthase inhibitor-resistant Palmer amaranth (Amaranth palmeri) biotype. WeedTechnol., 11 132-137. 

Hall, L.M., K.M. Stromme, G.P. Horsman, and M.D. Devine (1998). Resistance to acetolactate synthase inhibitors and quinclorac in a biotype of false cleavers (Galium spurium). Weed Sci., 46 390-396. 

Saari, L.L., J.C. Cotterman, and D.C. Thill (1994). Resistance to acetolactate synthase-inhibitor herbicides. In Powles, S.B. and Holtum, J.A.M., eds., Herbicide Resistance in Plants Biology and Biochemistry. Boca Raton, FL Lewis Publishers, pp. 83-139. 

This has changed dramatically in recent years, as is apparent throughout the herbicide chapters of this book. Of particular note are the surprising speed of resistance development to acetolactate synthase inhibitors (Mazur al., Gressel, this volume), and the emergence of multiply resistant ryegrass and blackgrass biotypes noted earlier. 

Molecular Characterization of Resistance to Acetolactate Synthase Inhibitors in Lindernia micrantha Origin and Expansion of Resistant... 

Eberlein, C.V., M.J. Guttieri, C.A. Mallory-Smith, D.C. Thill, and R.J. Baerg (1997). Altered acetolactate synthase activity in ALS-inhibitor resistant prickly lettuce (Lactuca serriola). Weed Sci., 45 212-217. 

Shaner, D.L. and R.G. Lym (1991). Mechanism of resistance to acetolactate synthase/acetohydroxyacid synthase inhibitors. Proc. West. Soc. Weed Sci., 44 122-125. 

It is not yet clear whether such factors will delay the rate of appearance of other types of resistance e.g. the multiple resistances to grass-killing herbicides in wheat, or to inhibitors of acetolactate synthase, where the fitness of resistant biotypes may be higher. 

Both compounds are inhibitors of the acetolactate synthase enzyme, also known as aceto hydroxy acid synthase (AHAS) and are classified in group B by the Herbicide Resistance Action Committee HRAC. Table 2.6.1 gives the physicochemical properties of 1 and 2. 

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