CHANGES IN ESTERASES IN RESPONSE TO BLAST INFECTION IN FINGERMILLET SEEDLINGS

The esterases of susceptible and resistant fingermillet seedlings were studied during infection. Infected susceptible genotype showed higher esterase activity compared with the resistant genotype. Isoenzyme 12 was found in all the developmental stages. On infection, isoenzyme 11 was suppressed in susceptible genotype but isoenzymes 3 and 4 appeared in the resistant genotype. Based on the inhibitor studies, isoenzyme 12 can be classified as a general esterase, and isoenzymes 3 and 4 wer e classified as carboxyl- and aryl-esterases, respectively. Isoenzyme 12 was relatively stable to almost all treatments. The carboxylesteras e (IE3) was resistant to Zn2+ ions, 80 degrees and pH 4 treatments. Ar ylesterase (IE4) was stable to Mg2+ only. Copyright (C) 1996 Elsevier Science Ltd