The Distribution of Catalase Activity, Isozyme Protein, and Transcript in the Tissues of the Developing Maize Seedling

Abstract

The catalase activity, CAT-2 and CAT-3 isozyme protein levels, and the steady-state mRNA levels for each of the three catalase genes were determined in the scutellum, root, epicotyl, and leaf of the developing maize (Zea mays L.) seedling. Catalase activity was highest in the scutellum, with 10-fold lower enzyme activity in the leaf and epicotyl. Very low levels of catalase activity were found in the root. The highest levels of CAT-2 protein were found in the scutellum, with about 10-fold lower levels in the green leaf.

Manipulation of Catalase Levels Produces Altered Photosynthesis in Transgenic Tobacco Plants1

“…During maize seedling development the distribution of catalase activity and isozyme protein were usually correlated with the steadystate level of mRNAs (Redinbaugh et al, 1990), but exceptions were noted. For example, Redinbaugh et al (1990) discuss experiments conducted during maize seedling development in which a catalase mRNA was present in one instance, although the catalase protein was not detected, and they cite another example in which the transcript level remained high when the isozyme protein was decreasing.…”

“…During maize seedling development the distribution of catalase activity and isozyme protein were usually correlated with the steadystate level of mRNAs (Redinbaugh et al, 1990), but exceptions were noted. For example, Redinbaugh et al (1990) discuss experiments conducted during maize seedling development in which a catalase mRNA was present in one instance, although the catalase protein was not detected, and they cite another example in which the transcript level remained high when the isozyme protein was decreasing. Also, in a careful developmental study of cotton seedlings, the steady-state level of mRNAs for two different catalase subunits did not reflect the catalase activity or catalase protein levels (Ni and Trelease, 1991), and it was concluded that accumulation of the subunits was primarily controlled at the posttranscriptional level.…”

Expression of the maize Cat3 catalase gene is under the influence of a circadian rhythm.

“…1.11.1.6, denoted CAT-1, CAT-2, and CAT-3) are encoded by the three unlinked structural genes Cat], Cat2, and Cat3, respectively (13). These three genes have unique patterns of expression in the tissues of the developing maize seedlings, including the dark-and light-grown shoot (13,14). The Cat) gene is "constitutively" expressed in that both the CAT-1 isozyme and Cat] transcript can be detected at low levels in all tissues throughout the development of light-and darkgrown seedlings (13)(14)(15).…”

Molecular and biochemical investigation of the mechanisms of acclimation to chilling stress in maize seedlings

“…In maize, CAT is present as four isozymes , only two of which (CAT 1 and CAT3) are present in slioots and roots of dark-grown maize seedlings. In the coleoptile and leaf, CAT 1 and CATS are present during early growth and upon exposure to light, CAT1 activity declines and CAT2 appears (Tsaftaris et al, 1983) although cat1 transcripts are present throughout early shoot development (Redinbaugh et al, 1990a). In mature leaves, CAT2 is localized in the bundle sheath cells while CAT1 and CAT3 are present in the mesophyll cells (Tsaftaris et al, 1983).…”

“…Roots contain primarily CAT 1 although cat3 transcripts and protein have been detected at low levels (Redinbaugh et al, 1990a). No documentation is available regarding the expression of catalase isozymes in maize mesocotyls.…”