Diversity of Insecticidal PA1b Homologs among Legume Seeds from Middle Eastern Region

Legumes play a central role in various food systems, with significant socio-economic and environmental impacts. Their high protein content, composed mainly of globulins and albumins, makes them valuable for human food and animal feed. Among the albumins, is Pea Albumin 1 b (PA1b), a 37 amino acid peptide, extracted from the seeds of the pea Pisum sativum. The protein displays the knottin scaffold and exhibits potent insecticidal activity against certain insects including cereal weevils and mosquitoes. This toxicity is attributed to the coexistence of several isoforms in peas. The natural diversity of PA1b-like molecules within the legume species of the Fabaceae family has been studied using various molecular, biochemical, and bioinformatic tools. Several A1 genes coding for this peptide have been characterized in soybeans, bean, barrel medick and other legume species. The aim of is study is to precisely characterize partial A1 genes in legumes of the Faboideae subfamily from the Middle East region using PCR homology. Specifically, the research focuses on the sequence structure of Pea Albumin 1 b (PA1b) variants and establishes phylogenetic relationships between these sequences and publicly available A1b homologs. The toxic effects of seed flour containing PA1b-like molecules are assessed, demonstrating that the newly characterized PA1b homologs retain structural conservation. The study observes both conservation and diversification among A1b homologs, consistent with the divergence of lineages within the Fabaceae family. The toxic effects associated with putative A1b molecules are found across different species and within the same species from different geographical origins. In particular, novel candidates such as Vicia sativa and Medicago minima show promising insecticidal A1b activity. Further analysis of isoforms from these species, including an examination of their expression in different tissues and organs should be undertaken to facilitate the potential use of A1b molecules in agricultural practice.