Enzymatic pathways in sweet potato (Ipomoea batatas) starch synthesis: A biochemical perspective

Starch is a critical carbohydrate stored in the tubers of sweet potato (Ipomoea batatas), providing energy reserves essential for plant growth and human consumption. This study investigates the enzymatic pathways involved in starch biosynthesis in sweet potato, focusing on key enzymes such as ADP-glucose pyrophosphorylase (AGPase), starch synthase, branching enzyme, and debranching enzyme. We also explore how environmental factors, including temperature, light, and nutrient availability, influence enzyme activity and gene expression across different developmental stages. The results show that enzyme activity peaks during the mid-developmental stage, coinciding with maximal starch accumulation. Temperature stress (30°C and 35°C) and nutrient deficiencies significantly reduce enzyme activity and gene expression, while continuous light promotes higher enzyme activity compared to continuous dark conditions. Gene expression analysis reveals that the transcriptional regulation of starch biosynthetic genes mirrors enzyme activity, further indicating the regulatory role of environmental factors. These findings provide a deeper understanding of the molecular and biochemical mechanisms governing starch biosynthesis in sweet potato. The insights gained from this study have potential applications in breeding strategies aimed at improving starch yield, quality, and resilience to environmental stressors, offering benefits for both agricultural productivity and industrial uses such as biofuels and food processing.