Seed Biotechnology



Some animals and plants -and most seeds- survive extreme dehydration by entering a state of almost imperceptible metabolic activity during desiccation. Our aim is to understand the regulation of an embryonic program of gene expression that our research has associated with both seed desiccation tolerance and seed longevity. More recently we could implicate the same program in protection of chloroplasts and in enhancing the biogenesis of the photosynthetic apparatus, immediately after seed germination during seedling emergence. The identification of specific regulators such as HSFA9 allowed us to evaluate the biotechnological potential of such a genetic program. Thus, for example, we were able to reduce or increase seed longevity in transgenic plants of Nicotiana tabacum, the model crop used in most of our studies. HSFA9-mediated effects in seedlings include outstanding tolerance to drastic dehydration and oxidative stress conditions, in particular the protection of leaves and the photosynthetic apparatus (the PSI, PSII in chloroplasts), In addition, and by acting upstream of red light (PHYB) and far-red light (PHYA) receptors, HSFA9 enhances chloroplast biogenesis during the early steps of seedling establishment. Our research thus revealed a novel connection between the regulation of seed maturation and seedling photomorphogenesis, both involving HSFA9, an embryonic Heat Stress Transcription factor (HSF). Our most recent results show that such a connection is wider, as it also involves complex effects on blue-light (CRY1) and UV-B light (UVR8) receptors. In all, the results our research might help obtaining crops better adapted to the negative effects as consequence of an imminent global climate change.