Abstract
For human food security, the preservation of 7.4 million ex-situ germplasm is a global priority. However, ex-situ-conserved seeds are subject to aging, which reduces their viability and ultimately results in the loss of valuable genetic material over long periods. Recent progress in seed biology and genomics has revealed new opportunities to improve the long-term storage of ex-situ seed germplasm. This review summarizes the recent improvements in seed physiology and genomics, with the intention of developing genomic tools for evaluating seed aging. Several lines of seed biology research have shown promise in retrieving viability signal from various stages of seed germination. We conclude that seed aging is associated with mitochondrial alteration and programmed cell death, DNA and enzyme repair, anti-oxidative genes, telomere length, and epigenetic regulation. Clearly, opportunities exist for observing seed aging for developing genomic tools to increment the traditional germination test for effective conservation of ex-situ germplasm.