Seed Longevity and Ageing: A Review on Physiological and Genetic Factors with an Emphasis on Hormonal Regulation

Abstract

Upon storage, seeds inevitably age and lose their viability over time, which determines their longevity. Longevity correlates with successful seed germination and enhancing this trait is of fundamental importance for long-term seed storage (germplasm conservation) and crop improvement. Seed longevity is governed by a complex interplay between genetic factors and environmental conditions experienced during seed development and after-ripening that will shape seed physiology. Several factors have been associated with seed ageing such as oxidative stress responses, DNA repair enzymes, and composition of seed layers. Phytohormones, mainly abscisic acid, auxins, and gibberellins, have also emerged as prominent endogenous regulators of seed longevity, and their study has provided new regulators of longevity. Gaining a thorough understanding of how hormonal signalling genes and pathways are integrated with downstream mechanisms related to seed longevity is essential for formulating strategies aimed at preserving seed quality and viability. A relevant aspect related to research in seed longevity is the existence of significant differences between results depending on the seed equilibrium relative humidity conditions used to study seed ageing. Hence, this review delves into the genetic, environmental and experimental factors affecting seed ageing and longevity, with a particular focus on their hormonal regulation. We also provide gene network models underlying hormone signalling aimed to help visualize their integration into seed longevity and ageing. We believe that the format used to present the information bolsters its value as a resource to support seed longevity research for seed conservation and crop improvement.

Quercetin and Rutin as Tools to Enhance Antioxidant Profiles and Post-Priming Seed Storability in Medicago truncatula

“…that stabilize macromolecules, membranes and cellular structures [34,77] or processes that preserve DNA integrity [19,78]. Above these layers, phytohormones regulate seed maturation, germination and stress responses, with determinant effects on seed longevity [23]. Further research focusing on the contribution of these factors in different model species and experimental systems is necessary to outline a comprehensive model of post-priming seed aging.…”

“…To understand post-priming storability, the interaction between priming and aging needs to be investigated. The scientific literature focused on seed aging and longevity is abundant and established, exploring molecular and physiological dynamics, ecological and agricultural implications, diagnostic methods and mitigation strategies [19][20][21][22][23]. Seeds progressively deteriorate during prolonged storage, with storability varying depending on the species, ecotypes and storage practices optimized for orthodox and recalcitrant seeds [24,25].…”

Transcriptomic Profiling of Two Rice Thermo-Sensitive Genic Male Sterile Lines with Contrasting Seed Storability after Artificial Accelerated Aging Treatment

“…Physiological changes inevitably occur inside the seed during storage, resulting in a decline or loss of seed vitality [8]. In southern China, rice seeds are usually stored in energy-consuming ways, such as using storage warehouses with controllable temperature and humidity or building low-temperature closed grain warehouses filled with inert gases, which also cause many environmental problems [9]. Therefore, enhancing the seed storability of TGMS lines is an economical and environmentally friendly way to cope with the surplus of hybrid seeds.…”

“…Seed aging is associated with other factors, such as plant phytohormones [9]. Abscisic acid (ABA) and gibberellin (GA) are recognized as key phytohormones in regulating seed dormancy and germination [21].…”