Emerging economies (Brazil, Russia, India, China and other countries) are expected to play a major role in the global economy during the 21st century. Some of these countries have exceptional soil and climate characteristics that determine evident advantages for food production. These features, combined with a rapid adoption of technologies generated by industrialized economies (i.e. transgenic crops and others), have been instrumental to fast expansion of agricultural production in recent years. For such reasons, some of these economies are strongly based on production of food commodities (agriculture represents 18.3, 12.6, 9.4 and 8.1% of the gross domestic product of India, China, Argentina and Brazil, respectively) and have a great share in global food production. Despite the mentioned characteristics that make agricultural activity so efficient in these countries, generation of new technologies in order to guarantee the systems' sustainability and add value to agricultural production (by means of, for example, royalties or technologies generated with local criteria) relies on research carried out in areas such as crop science, biotechnology, ecology, plant breeding and, of course, seed science. However, the amount of local research carried out in these countries appears not to be in agreement with the importance that agricultural production has in their economies. For example, Argentina produces 16.20% of the soybean produced in the world but only 2% of the scientific literature related to this crop in its many aspects. This imbalance between the weight that agricultural production has on these economies and generation of knowledge in the related disciplines, threatens the sustainability of these economic models and, therefore, of global food production. Seed science, then, is called on to play a major role in these emerging economies, through the different approaches (i.e. ecological, physiological, agronomical and molecular) that the discipline has to offer. Here we provide four examples in which seed science (through any of the four approaches mentioned above): (1) has identified subtle but crucial components of newly adopted production systems; (2) has proposed means for their adjustment in order to secure the sustainability of those systems; and (3) might help to add value to agricultural production through the development of new germplasm displaying specific features (e.g. timing of dormancy release adjusted to industrial necessities).

Seed researchers, like anybody else working with materials containing genes, have to deal with a variety of rules. Their ‘freedom to operate’ does not only depend on intellectual property rights but also on various rights arising from biodiversity policies and possibly traditional knowledge. The most relevant are, however, patents on both materials and biotechnologies. It is in this field that recent developments indicate that the pendulum of ever-increasing levels of rights has started to swing back a little. This is due to recent court cases both in the USA and Europe, and emerging political debates in various countries. After describing the general policy arena involving national sovereign rights, private rights and ‘group-rights’ we focus on recent trends in the patent system. Seed scientists hardly even had to deal with such rights in the past, but in the 21st century they need to be aware of their implications.

The seed consists of three distinct regions, the zygotic embryo and endosperm and the maternal seed coat. Development of the seed requires co-ordinated growth and differentiation within each of these regions. Although the major events that occur during seed development have been studied extensively at the anatomical, physiological and molecular level, a comprehensive understanding of gene activity in each seed region has been lacking. DNA microarrays and extensive sequencing of cDNA libraries permit genome-wide analyses of mRNA populations of biological samples. We review recent studies of genome-wide gene activity that illustrate approaches used to provide new insights into the processes that occur during seed development.

Temperature has a key influence over seed dormancy and germination, allowing wild plants to synchronize their life history with the seasons. In this review we discuss the signalling pathways through which temperature is integrated into seed physiology and the control of primary and secondary dormancy, with an emphasis on understanding maternal effects and responses dictated by the zygotic tissues. A key emerging paradigm is that temperature signalling in seeds must be understood in relation to whole plant genetics and physiology, as overlapping pleiotropic roles for temperature sensing and hormone signalling pathways are commonplace.

Thioredoxins (Trxs) are widely distributed, small proteins that function in redox regulation in a broad spectrum of cellular reactions. Experimental work with barley, wheat and a legume (Medicago truncatula) has established thioredoxin h (Trx h) as a central regulatory protein in seeds, reducing disulphide (S–S) groups of diverse seed proteins, including storage proteins, enzymes and enzyme inhibitors. Trxs appear to be particularly important in plants, as a large number of genes are present compared to mammalian organisms. In Arabidopsis thaliana there are approximately 20 different genes for classical Trxs, and large Trx gene families have also been found in cereals, such as rice, barley, wheat and sorghum. Extensive evidence indicates that adding Trx, reduced nicotinamide adenine dinucleotide phosphate (NADPH) and NADP-thioredoxin reductase (NTR) to cereal flour or seed preparations reduces disulphide (S–S) linkages of storage proteins. The early in vitro studies have been complemented with transgenic barley seed, overexpressing Trx h in protein bodies of the barley endosperm, which showed accelerated germination and early or enhanced expression of associated enzymes, i.e., α-amylase and pullulanase. Overexpression of Trx h levels in wheat was subsequently shown to (1) enhance protein solubility and digestibility, (2) reduce allergenicity of wheat gliadins, and (3) improve dough quality from poor-quality wheat flour. Most recently, we have demonstrated that down-regulation in wheat of Trx h9, a unique thioredoxin, leads to a reduction in the incidence of pre-harvest sprouting, demonstrated in several varieties over multiple generations with field-grown material. Yield and starch content were increased while baking quality in the high-gluten variety remained unchanged. These observations led to the intriguing question of how changes in the endosperm are communicated to the embryo. Studies of Trx h9, a membrane-associated Trx h that can move from cell to cell, provide suggestive evidence for a role of Trx h9 in intercellular communication of redox state.

There is a worldwide consensus that the production of food, biomolecules and bioenergy should be sustainably intensified within the next decades. To achieve these goals will depend on the intensification of current practices in agricultural systems fused with a wider understanding and acceptance of genomics, metabolomics, synthetic biology and metabolic engineering. However, genetically modified-derived crops, including commodities and non-commodities, may contribute to establishing a new parameter in the agricultural, pharmaceutical and industrial sectors. Seeds will also play an important role in allowing large-scale production of innovative molecules prospected from biodiversity.

Seed quality is a complex trait that is the result of a large variety of developmental processes. The molecular-genetic dissection of these seed processes and their relationship with seed and seedling phenotypes will allow the identification of the regulatory genes and signalling pathways involved and, thus, provide the means to predict and enhance seed quality. Natural variation for seed-quality aspects found in recombinant inbred line (RIL) populations is a great resource to help unravel the complex networks involved in the acquisition of seed quality. Besides extensive phenotyping, RILs can also be profiled by -omics technologies, such as transcriptomics, proteomics and metabolomics in a sophisticated so-called generalized genetical genomics approach. This combined use of physiology, genetics and several -omics technologies, followed by advanced data analysis, allows the construction of regulatory networks involved in the various attributes of seed and seedling quality. This type of analysis of the genetic variation in RIL populations in combination with genome-wide association (GWA) studies will allow a relatively rapid identification of genes that are responsible for quality-related traits of seeds and seedlings. New developments in several -omics technologies, especially the fast-evolving next-generation sequencing techniques, will make a similar system-wide approach more applicable to non-model species in the near future and this will be a huge boost for the potential to breed for seed quality.

The strong mechanistic relationship between climatic factors and seed dormancy and germination suggests that forecast climatic changes will significantly affect seed bank persistence. This review focuses on the potential impact of changing temperature, rainfall and fire regimes on the longevity of long-term persistent seed-banks. Currently, there are few studies investigating the mechanistic responses of demographic processes, such as seed-bank dynamics, to forecast climate change. However, from the work that has been published, several key points have been highlighted. First, increased air temperatures will produce significantly higher soil temperatures in open and sparsely vegetated habitats. Some evidence shows that this could accelerate the decline of seed viability and compromise bet-hedging strategies of species in dryland regions. Second, changes to rainfall season may determine the relative success of recruitment, with lower levels of success producing net losses to seed bank longevity. Finally, higher temperatures are likely to produce increased fire frequency, compromising the persistence of plant populations dependent on long-lived seed banks. Improving our understanding of both the mechanistic response and adaptive capacity of seed banks to climate change will provide a solid basis for improved predictions of future species distributions and risk of extinction, particularly in ecosystems subjected to temporally stochastic disturbances. It is necessary to develop functional groups based on key life-history trait responses to changing environmental conditions, to enable broader-scale predictions of distribution and persistence in the future.

Methods of evaluation of seed quality providing accurate prediction of seed performance under field conditions are needed by the seed industry. Various physiological tests, i.e. germination tests in suboptimal conditions of temperature, oxygenation and water potential of the medium, or accelerated ageing and controlled deterioration allow sensitive differentiation between seed lots. A better understanding of the biochemical, cellular and molecular mechanisms involved in the acquisition of seed vigour during seed development, in the germination process and in seed deterioration during ageing could suggest various markers of seed quality. Among these markers, electrolyte leakage and ethylene production during imbibition, cell-cycle markers (DNA replication, β-tubulin), soluble sugar metabolism (in particular, changes in the raffinose family of oligosaccharides), proteins (11S globulin B-subunit, late embryogenesis abundant protein, heat-shock protein) and the efficiency of reactive oxygen species scavenging through antioxidant defence systems (e.g. catalase activity) have potential for the evaluation of the state of seed maturity, seed performance and effectiveness of seed priming treatments. Use of global approaches such as transcriptomic, proteomic or metabolomic analysis could also result in the identification of new markers.

Seed quality standards enable seed users to achieve their objectives in the establishment of uniform seedlings to a high and reliable level for a range of agricultural and horticultural crops, growing systems and market outlets. Quality standards of commercial seed lots are determined by their positions on the seed survival curves and the shape of their germination progress curves. Although comparative descriptions of germination curves can be achieved by the calculation of the mean germination time (MGT; delay to radicle emergence), single early counts of radicle emergence provide a convenient means of predicting MGT and differences between seed lots. Evidence is presented for an ageing and metabolic repair hypothesis as the overall physiological basis to explain the principles behind the standard germination and vigour tests (ageing, electrolyte leakage, cold test, germination rate and seedling size). The work of the International Seed Testing Association (ISTA) in developing convenient, inexpensive and internationally repeatable tests is illustrated.

The Brazilian literature on seed germination testing of tropical forest species, although still insufficient, is extensive for species with economical potential. However, this information is still fragmented and often reported in scientific communications of modest circulation. In this summary, we present the results of a validation process for germination tests on Brazilian forest species, which had as a starting point the ample reviewing of current methods, besides exhaustive pre-testing in certified laboratories. Specific protocols were created for each species, including substrate, temperature, seed disinfection, breaking of dormancy, seedling classification and other information. These protocols were sent to research laboratories and accredited by the Ministry of Agriculture, together with seed lots of three distinct qualities. The presuppositions of normality of the residuals and homoscedasticity of the variations were previously tested and the completely randomized factorial design statistical model was applied to the normal seedlings of each species. After this analysis, germination test methods for seeds of Astronium fraxinifolium, Ceiba speciosa, Cybistax antisyphilitica, Enterolobium contortisiliquum, Guazuma ulmifolia, Lafoensia pacari, Mimosa caesalpiniaefolia, Peltophorum dubium, Pseudobombax tomentosum and Pterogyne nitens, all forest species of different Brazilian biomes, were considered to be validated.

Winter rape has a life cycle which necessitates rapid testing of seed quality for the seed production sector, namely between July after harvest of the previous crop and August when the next crop establishment begins. As this crop is the fourth most important crop in France, and the most important oilseed crop, the French seed testing station GEVES has managed several research programmes to study seed quality in this species. These collaborative programmes have not only associated seed science with seed technology but also informatics and electronic engineering to provide seed testing tools that are already used by the seed sector, such as conductivity, or innovative tools, such as germination time courses monitored by computer imaging. Forthcoming tools have also been looked at in order to control seed storage potential, which is often used nowadays to anticipate the next season. Biochemical markers have been studied, including seed-specific biotinylated proteins or enzymes involved in free radical (reactive oxygen species) scavenging, such as catalase. Both are well correlated with seed ageing and have been tested to provide an ELISA-like assay for seed testing laboratories. Germination monitoring by computer imaging is now used by research and breeding institutes to phenotype varying seed material, including genotype or mutant collections, primed or ageing seed lots, etc. The next step in seed quality testing in oilseed rape is to characterize variation in germination and seed vigour in order to stabilize optimal yield. This aim constitutes a new international project involving high-throughput phenotyping and genotyping of a large collection of genetically diverse rapeseed genotypes (double haploid populations or diverse cultivars).

Seed treatments are used globally on a wide range of field, vegetable and ornamental seeds, for efficient early season control of insects and diseases. However, specific seed-treatment compounds may be phytotoxic and this phytotoxicity is most acute in laboratory germination tests. Several strategies have been developed to alleviate seed-treatment phytotoxicity that include spatial separation of the pesticide from the seed. This can be accomplished by the application of the active compounds at the end of pelleting or by using a two-pellet system, termed ‘smart-pill technology’. Another approach is to detoxify or adsorb the agrochemical in a standard germination test by applying a peat medium over the seeds in a roll towel or blotter test. Many new seed-treatment chemicals have systemic activity, and the efficacy of these systemic seed treatments depends on the ability of these applied chemical compounds to be absorbed, and then transported in the developing plant. The present article describes seed-coat permeability to systemic seed treatments, examined by monitoring the movement of fluorescent tracers into intact seeds during imbibition. Two moderately lipophilic, fluorescent tracers have been used – rhodamine (ionic) and coumarin (non-ionic) – which differ mainly in electrical charge. Seed-coat permeabilities of particular species have been grouped into three categories: (1) permeable to both tracers; (2) selectively permeable to only coumarin; and (3) non-permeable to both tracers. The ability of a particular compound to diffuse through the seed coat is related to the chemical nature of the seed-covering tissues and the physico-chemical properties of the compound applied.