A passive repression mechanism that hinders synergic transcriptional activation by heat shock factors involved in sunflower seed longevity

Different genetic programs that are active during late stages of zygotic embryogenesis are involved in seed phenotypes as longevity, basal thermotolerance, and desiccation tolerance. In sunflower, Heat Shock Factor A9 (HaHSFA9) controls one of such programs, the HaHSFA9 program. Overexpression of HaHSFA9 in seeds of transgenic tobacco showed the involvement of this transcription factor in basal thermotolerance and longevity; HaHSFA9 activated a genetic program that includes specific small Heat Shock Protein (sHSP) genes, which are expressed mainly (or exclusively) during zygotic embryogenesis in seeds (Prieto-Dapena et al., 2006). We also used an active-repressor dominant-negative (DN) form of HaHSFA9, and thus we obtained a substantial reduction of both the accumulation of specific sHSPs and of seed longevity (Tejedor-Cano et al., 2010).This work was supported by the European Regional Development Fund (FEDER) and the Spanish Secretary of Research, Development, and Innovation (Grants BIO2008-00634 and BIO2011-23440 to JJ). Additional funds were obtained from the Andalusian Regional Government (Grant BIO148 to JJ).Peer reviewe

A passive repression mechanism that hinders synergic transcriptional activation by heat shock factors involved in sunflower seed longevity

Different genetic programs that are active during late stages of zygotic embryogenesis are involved in seed phenotypes as longevity, basal thermotolerance, and desiccation tolerance. In sunflower, Heat Shock Factor A9 (HaHSFA9) controls one of such programs, the HaHSFA9 program. Overexpression of HaHSFA9 in seeds of transgenic tobacco showed the involvement of this transcription factor in basal thermotolerance and longevity; HaHSFA9 activated a genetic program that includes specific small Heat Shock Protein (sHSP) genes, which are expressed mainly (or exclusively) during zygotic embryogenesis in seeds (Prieto-Dapena et al., 2006). We also used an active-repressor dominant-negative (DN) form of HaHSFA9, and thus we obtained a substantial reduction of both the accumulation of specific sHSPs and of seed longevity (Tejedor-Cano et al., 2010).This work was supported by the European Regional Development Fund (FEDER) and the Spanish Secretary of Research, Development, and Innovation (Grants BIO2008-00634 and BIO2011-23440 to JJ). Additional funds were obtained from the Andalusian Regional Government (Grant BIO148 to JJ).Peer reviewe