Seeds

California sage scrub is an endangered, shrub-dominated, southern California ecosystem threatened by increasing fire frequencies and type-conversion to non-native grasslands. Once non-native grasses become established, their presence promotes more frequent fires, perpetuating grass dominance. To better understand how fire influences soil seed bank assemblages, we examined soil seed banks in burned and adjacent unburned sage scrub at the Robert J. Bernard Field Station (BFS) in two areas that burned in September 2013 and May 2017. In contrast to a previous soil seed bank study in California sage scrub, we found that unburned soil seed banks in sage scrub at the BFS were primarily composed of native seeds (88% of sprouts in unburned areas were native), highlighting that soil seed bank dynamics differ among California sage scrub sites. Despite burned areas supporting elevated densities of non-native seeds (the majority of which included Festuca myuros, a non-native grass), soil seed banks in our burned areas retained native seeds (21% of sprouts in burned areas were native), including native shrub species, suggesting that not all sage scrub habitats are primed to transition to non-native grasslands following disturbances. However, elevated densities on non-native seedlings in burned areas highlight the vulnerability of sage scrub to fire disturbances and the subsequent establishment of non-native grasses.

Two well-known recessive mutations (a, conditioning white flowers and unpigmented testa; and r, conditioning wrinkled seeds) were found to be major contributors to the loss of germination percentage in garden pea (Pisum sativum L.) when seeds were maintained at cool temperatures (5 °C) for extended periods. After approximately 20 years in storage, seeds homozygous for the unpigmented mutation displayed an average germination rate about 20% lower than wildtype seeds, while wrinkled seeds displayed a rate about 25% less. Seeds homozygous for both the a and r mutations (a combination typical of many commercial cultivars) exhibited a reduction in germination percentage of about 50% over the storage period, indicating that the two mutations have an additive effect on the ageing process. Additional results involving a second mutation (a2) in the phenylpropanoid pathway, as well as information available from the literature that a second, independent mutation in starch synthesis (r_b) also reduces seed longevity, suggest that an intact phenylpropanoid pathway and a normally functioning starch synthesis pathway are necessary for optimal storage life of pea seeds.

Wild seeds constitute a taxonomically diverse and underexplored reservoir of C18-series bioactive fatty acids (BFAs) with significant nutritional, biomedical, and industrial relevance. This review integrates current knowledge on their lipid composition, metabolic architecture, and potential applications. Numerous wild taxa accumulate high levels of oleic, linoleic, α-linolenic, γ-linolenic, and stearidonic acids, while others synthesise structurally specialised compounds such as punicic, petroselinic, and sciadonic acids. These FAs, together with tocopherols, phytosterols, and phenolics, underpin antioxidant, anti-inflammatory, immunomodulatory, and cardiometabolic effects supported by in vitro and in vivo evidence. The occurrence of these unusual lipids reflects lineage-specific modulation of plastidial and endoplasmic-reticulum pathways, including differential activities of SAD, FAD2/3, Δ6- and Δ5-desaturases, elongases, and acyl-editing enzymes that determine the final acyl-CoA and TAG pools. Wild seed oils show strong potential for translation into functional foods, targeted nutraceuticals, pharmacologically relevant lipid formulations, cosmetic ingredients, and bio-based materials. However, their exploitation is constrained by ecological sustainability, oxidative instability of PUFA-rich matrices, antinutritional constituents, and regulatory requirements for novel lipid sources. This review positions wild seeds as high-value, underused lipid resources with direct relevance to health and sustainability. It underscores their potential to enhance nutritional security and offer alternatives to conventional oil crops.