Genome‐wide association mapping and biochemical markers reveal that seed ageing and longevity are intricately affected by genetic background and developmental and environmental conditions in barley

Abstract

Globally, over 7.4 million accessions of crop seeds are stored in gene banks, and conservation of genotypic variation is pivotal for breeding. We combined genetic and biochemical approaches to obtain a broad overview of factors that influence seed storability and ageing in barley (Hordeum vulgare). Seeds from a germplasm collection of 175 genotypes from four continents grown in field plots with different nutrient supply were subjected to two artificial ageing regimes. Genome-wide association mapping revealed 107 marker trait associations, and hence, genotypic effects on seed ageing. Abiotic and biotic stresses were found to affect seed longevity. To address aspects of abiotic, including oxidative, stress, two major antioxidant groups were analysed. No correlation was found between seed deterioration and the lipid-soluble tocochromanols, nor with oil, starch and protein contents. Conversely, the water-soluble glutathione and related thiols were converted to disulphides, indicating a strong shift towards more oxidizing intracellular conditions, in seeds subjected to long-term dry storage at two temperatures or to two artificial ageing treatments. The data suggest that intracellular pH and (bio)chemical processes leading to seed deterioration were influenced by the type of ageing or storage. Moreover, seed response to ageing or storage treatment appears to be significantly influenced by both maternal environment and genetic background.

Inference of Longevity-Related Genes from a Robust Coexpression Network of Seed Maturation Identifies Regulators Linking Seed Storability to Biotic Defense-Related Pathways

“…Furthermore, antioxidants such as glutathione (Kranner et al, 2006), tocopherols (Sattler et al, 2004), and flavonoids present in the testa (Debeaujon et al, 2000) also play a role in longevity by alleviating oxidation occurring during storage. Seed longevity is a quantitative trait for which genetic variation is observed among naturally occurring accessions and quantitative trait loci have been obtained in several crops (Bentsink et al, 2000;Nguyen et al, 2012;Nagel et al, 2015).…”

Mining seed proteome: from protein dynamics to modification profiles

“…During the last decades, soybeans (Glycine max), common (dry) beans (Phaseolus vulgaris) and peanuts (Arachis hypogaea) have become major sources of food protein (Messina, 1999;Asgar et al, 2010). Indeed, soybeans were cultivated on an area of approximately 100 million ha with crop yields of 238 million tons in the year 2010; soybeans account for the most pronounced portion of world legume yields (Nedumaran et al, 2015). The area share of this crop in the developed world (Europe, the United States and Canada) is much higher than in developing countries (Nedumaran et al, 2015).…”

“…Indeed, soybeans were cultivated on an area of approximately 100 million ha with crop yields of 238 million tons in the year 2010; soybeans account for the most pronounced portion of world legume yields (Nedumaran et al, 2015). The area share of this crop in the developed world (Europe, the United States and Canada) is much higher than in developing countries (Nedumaran et al, 2015). On the other hand, according to the Food and Agriculture Organization of the United Nations, cereals such as maize (Zea mays), wheat (mostly Triticum aestivum), rice (Oryza sativa) and barley (Hordeum vulgare) are the most prominent sources of food carbohydrates (FAO, 2018).…”

“…On the biochemical level, these experiments can be complemented by oxidative stress assays (Bailly and Kraner, 2011;Kocsy, 2015). However, today, methods of functional genomics and systems biology provide an excellent opportunity to address seed quality on a principally new level, assuming an integrated systematic and physiology-based approach (Rajjou et al, 2008;Fu, Ahmed, and Diederichsen, 2015;Nagel et al, 2015;. Indeed, integration of transcriptomic, proteomic and metabolomic methodological platforms gives access to the whole network of metabolic events underlying gene expression (May et al, 2011;Mochida and Shinozaki, 2011;Brink-Jensen, Bak, Jorgensen, and Ekstrom, 2013).…”

Biology of Seed Vigor in the Light of -omics Tools

“…In the context of seed deterioration, seed vigor is often measured as seed longevity in storage which is relevant to seed conservation and seed bank operation efforts [4,5]. The processes involved in the loss of seed vigor during seed deterioration elucidate the complex biological phenomenon of seed vigor.…”