Bagnoli Francesca, Danti Susanna, Magherini Valentina, Cozza Radiana, Innocenti Anna M, Racchi Milvia L
Sezione di Genetica, Dipartimento di Biotecnologie Agrarie, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Florence, Italy.
Laboratorio di Botanica, Dipartimento di Ecologia, Edificio Polifunzionale, Università degli Studi della Calabria, 87030 Arcavacata di Rende, Cosenza, Italy.
Funct Plant Biol. 2004 May;31(4):349-357. doi: 10.1071/FP03203.
Two cDNA clones encoding catalase (Cat1 and Cat2) from peach [Prunus persica (L.) Batsch] were identified, that show homologies to other plant catalases. The nucleotide sequences of the two coding regions showed 88% identity to each other. The amino acid sequences predicted from the two full-length clones showed the highest homology to a catalase from cotton and Nicotiana plumbaginifolia L. and included C-terminal tri-peptides typical of those used to target proteins to peroxisomes. Southern hybridisation analysis suggested the existence of two catalase genes in peach. The expression of Cat1 and Cat2 was determined in seeds, vegetative tissue, leaves during the seasonal cycle and in leaves in response to light / dark treatments. Cat1 had high levels of expression only in leaf tissue and was responsive to light and seasonal changes. Cat2 had high levels of expression in in vitro shoots and was also responsive to seasonal changes, but not to light. In situ hybridisations to leaf tissue indicated that the expression of Cat1 was localised mainly in palisade cells, while Cat2 mRNA was present in the vascular tissue. The results of the expression analysis and in situ hybridisation suggest a role for Cat1 in photorespiration and for Cat2 in stress responses.
从桃[Prunus persica (L.) Batsch]中鉴定出两个编码过氧化氢酶的cDNA克隆（Cat1和Cat2），它们与其他植物过氧化氢酶具有同源性。两个编码区的核苷酸序列彼此间有88%的同一性。从两个全长克隆预测的氨基酸序列与棉花和烟草（Nicotiana plumbaginifolia L.）的过氧化氢酶具有最高同源性，并且包含用于将蛋白质靶向过氧化物酶体的典型C末端三肽。Southern杂交分析表明桃中存在两个过氧化氢酶基因。测定了Cat1和Cat2在种子、营养组织、季节性周期中的叶片以及响应光/暗处理的叶片中的表达。Cat1仅在叶片组织中高水平表达，并且对光和季节变化有响应。Cat2在离体芽中高水平表达，并且也对季节变化有响应，但对光无响应。对叶片组织的原位杂交表明，Cat1的表达主要定位于栅栏细胞，而Cat2 mRNA存在于维管组织中。表达分析和原位杂交的结果表明，Cat1在光呼吸中起作用，而Cat2在应激反应中起作用。
