Biological and Industrial Prospects of Polyamines in Silkworms: A Comprehensive Review

Abstract

Polyamines, specifically putrescine, spermidine, and spermine—are low molecular weight aliphatic cations that play essential roles in cellular growth, DNA stabilization, protein synthesis, and stress tolerance across biological systems. In the context of sericulture, recent studies have uncovered the multifaceted impact of polyamines on silkworm physiology, offering new avenues for improving silk yield and quality. This review consolidates current findings on the role of polyamines in regulating the cell cycle, enhancing nutritional indices, improving silk fiber characteristics, and boosting reproductive efficiency in Bombyx moriand wild silkworm species such as Antheraea mylitta. Supplementation with optimal concentrations of spermidine and spermine has been shown to promote larval growth, increase silk gland and cocoon weight, upregulate fibroin gene expression, and improve egg production and hatchability. These effects are particularly pronounced in hybrid strains, highlighting the potential of polyamines to exploit hybrid vigour in commercial sericulture. Molecular analyses, including FTIR and SEM, support structural enhancements in silk fibers, while histological studies demonstrate improved reproductive tissue development. Given their low cost, scalability, and ease of integration into existing rearing practices, polyamines present a promising biotechnological tool for sustainable sericulture. The review also identifies future research directions, including polyamine metabolism, dose optimization, and synergistic use with other biostimulants. Overall, polyamines represent a valuable asset for advancing silk production efficiency and quality in both laboratory and field conditions.