Regulation and Tissue-Specific Distribution of mRNAs for Three Extracellular Invertase Isoenzymes of Tomato Suggests an Important Function in Establishing and Maintaining Sink Metabolism

摘要: The aim of the present study was to gain insight into contribution extracellular invertases for sink metabolism in tomato (Lycopersicon esculentum L.). shows that invertase isoenzymes are encoded by a gene family comprising four members: Lin5, Lin6, Lin7, and Lin8. regulation mRNA levels internal external signals distribution source tissues has been determined compared with intracellular sucrose (Suc)-cleaving enzymes Suc synthase vacuolar invertase. specific Lin7 suggests an important function apoplastic cleavage cell wall-bound establishing maintaining metabolism. Lin6 is expressed under conditions require high carbohydrate supply. corresponding tissue-specific concentration elevated stress-related stimuli, growth-promoting phytohormone zeatin, response induction heterotrophic expression Lin5 gynoecia stamens, respectively, supplying carbohydrates these flower organs, whereas found be exclusively this organ.