Differential Expression of Chitinase and ß-l,3-Glucanase Genes in Various Tissues of Potato Plants

We have analyzed the tissue-specific expression o f chitinase, ß-l,3-glucanase and, for com ­ parison, phenylalanine am m onia-lyase genes in healthy, unstressed po ta to (Solanum tubero­ sum) plants by using R N A -R N A hybridization and im m unostaining techniques to localize the respective m R N A s and proteins in situ. P reparations o f leaf, flower, shoot tip, node and axillary bud revealed th a t chitinase exhibited a distinctive and characteristic expression p a t­ tern in being confined to the epiderm al cell layer, while ß-l,3-glucanase and phenylalanine amm onia-lyase were present to varying extents in m ost tissues o f these organs. These distinc­ tive patterns o f expression suggest fundam entally different roles for the two glucanohydrolases in the m etabolism o f unstressed plants.