Plant Non-Specific Lipid Transfer Proteins (nsLTPs): Comprehensive Functional Analysis and Defense Mechanisms

Non-specific lipid transfer proteins (nsLTPs) play a crucial role in lipid transport across membranes, contributing to cellular integrity and structural stability. These proteins are characterized by the presence of eight conserved cysteine residues that form four disulfide bonds and a hydrophobic cavity that is essential for lipid binding and transport. Interactions of nsLTPs with diverse ligands enable them to participate in key biological processes, including signal transduction, protein folding, membrane stabilization, and cell wall organization. Additionally, these proteins are integral to plant responses to abiotic and biotic stresses and to developmental processes, including growth, germination, and flowering. The interaction between nsLTPs and plant signaling molecules activates regulatory networks that modulate stress-responsive gene expression, reinforcing plant resilience under adverse conditions. Despite their functional significance, the evolutionary trajectory, subcellular localization, and regulatory mechanisms governing nsLTP expression remain limited, as reflected in previous reviews on nsLTPs. This review provides a comprehensive analysis of nsLTP evolution, roles in plant defense and signaling, functional diversity, updated subcellular localization, and future research directions based on recent findings.