The aim of this work was to examine the role of fructose 2,6-bisphosphate (fru 2,6P2) in the carbohydrate metabolism in carnation (Dianthus caryophyllus L.). For this purpose, transgenic plants harboring two modified bifunctional enzyme complementary DNAs of rat liver origin (6-phosphofructo-2-kinase/fructose 2,6-biphosphatase) were generated. Transformation with the kinase construct resulted in a 45% to 85% increase in fru 2,6P2 concentrations compared with the wild type. Transformation with the phosphatase construct reduced the fru 2,6P2 contents by 45% and 70%. These alterations in fru 2,6P2 amounts affected the key enzyme activities of sucrose and starch metabolism. Accordingly, plants with elevated fru 2,6P2 concentrations had high levels of starch, fructose, and triose phosphates, and low levels of sucrose, glucose, and hexose phosphates. In plants with reduced amounts of fru 2,6P2 different results could be observed in major carbohydrate compounds.
Pepper (Capsicum L.) is a major vegetable and spice crop worldwide. Global production of both fresh and dried fruit continues to increase steadily in terms of area harvested and yield. Various topics are addressed in this review, including recent additions to and clarification of Capsicum taxonomy, genetic resources of Capsicum, cytogenetic studies, the current status of our understanding of the mechanisms affecting the biosynthesis of capsaicinoids, the use of gene mutations to elucidate carotenoid biosynthetic pathways and their regulation, and recent advances in whole-genome sequencing and assembly.