The process of cold acclimation is an important adaptive response whereby many plants from temperate regions increase their freezing tolerance after being exposed to low non-freezing temperatures. The correct developm...The process of cold acclimation is an important adaptive response whereby many plants from temperate regions increase their freezing tolerance after being exposed to low non-freezing temperatures. The correct development of this response relies on proper accumulation of a number of transcription factors that regulate expression patterns of cold-responsive genes. Multiple studies have revealed a variety of molecular mechanisms involved in promoting the accumulation of these transcription factors. Interestingly, however, the mechanisms implicated in controlling such accumulation to ensure their adequate levels remain largely unknown. In this work, we demonstrate that prefoldins （PFDs） control the levels of HY5, an Arabidopsis transcription factor with a key role in cold acclimation by activating anthocyanin biosynthesis, in response to low temperature. Our results show that, under cold conditions, PFDs accumulate into the nucleus through a DELLA-dependent mechanism, where they interact with HY5, triggering its ubiquitination and subsequent degradation. The degradation of HY5 would result, in turn, in anthocyanin biosynthesis attenuation, ensuring the accurate development of cold acclimation. These findings uncover an unanticipated nuclear function for PFDs in plant responses to abiotic stresses.展开更多
The cultivation of CrylAb-expressing genetically modified MON810 （Bt maize） has led to public concern in Europe, regarding its impact on nontarget arthro- pods （NTAs）. We have assessed the potential effects of DKC...The cultivation of CrylAb-expressing genetically modified MON810 （Bt maize） has led to public concern in Europe, regarding its impact on nontarget arthro- pods （NTAs）. We have assessed the potential effects of DKC 6451 YG （MON810） maize on canopy NTAs in a farm-scale study performed in Central Spain during 3 years. The study focused on hemipteran herbivores （leafhoppers and planthoppers） and hymenopteran parasitic wasps （mymarids） collected by yellow sticky traps, which accounted for 72% of the total number of insects studied. The dynamics and abundance of these groups varied among years, but no significant differences were found between Bt and non-Bt maize, indicating that Bt maize had no negative effect on these taxa. Nonetheless, the CrylAb toxin was detected in 2 different arthropods collected from Bt maize foliage, the cicadellids Zyginidia scutellaris and Empoasca spp. A retrospective power analysis on the arthropod abundance data for our field trials has determined that Z. scutellaris and the family My- maridae have high capacity to detect differences between the Bt maize and its isogenic counterpart. The use of these canopy NTAs as surrogates for assessing environmental impacts of Bt maize is discussed.展开更多
文摘The process of cold acclimation is an important adaptive response whereby many plants from temperate regions increase their freezing tolerance after being exposed to low non-freezing temperatures. The correct development of this response relies on proper accumulation of a number of transcription factors that regulate expression patterns of cold-responsive genes. Multiple studies have revealed a variety of molecular mechanisms involved in promoting the accumulation of these transcription factors. Interestingly, however, the mechanisms implicated in controlling such accumulation to ensure their adequate levels remain largely unknown. In this work, we demonstrate that prefoldins （PFDs） control the levels of HY5, an Arabidopsis transcription factor with a key role in cold acclimation by activating anthocyanin biosynthesis, in response to low temperature. Our results show that, under cold conditions, PFDs accumulate into the nucleus through a DELLA-dependent mechanism, where they interact with HY5, triggering its ubiquitination and subsequent degradation. The degradation of HY5 would result, in turn, in anthocyanin biosynthesis attenuation, ensuring the accurate development of cold acclimation. These findings uncover an unanticipated nuclear function for PFDs in plant responses to abiotic stresses.
文摘The cultivation of CrylAb-expressing genetically modified MON810 （Bt maize） has led to public concern in Europe, regarding its impact on nontarget arthro- pods （NTAs）. We have assessed the potential effects of DKC 6451 YG （MON810） maize on canopy NTAs in a farm-scale study performed in Central Spain during 3 years. The study focused on hemipteran herbivores （leafhoppers and planthoppers） and hymenopteran parasitic wasps （mymarids） collected by yellow sticky traps, which accounted for 72% of the total number of insects studied. The dynamics and abundance of these groups varied among years, but no significant differences were found between Bt and non-Bt maize, indicating that Bt maize had no negative effect on these taxa. Nonetheless, the CrylAb toxin was detected in 2 different arthropods collected from Bt maize foliage, the cicadellids Zyginidia scutellaris and Empoasca spp. A retrospective power analysis on the arthropod abundance data for our field trials has determined that Z. scutellaris and the family My- maridae have high capacity to detect differences between the Bt maize and its isogenic counterpart. The use of these canopy NTAs as surrogates for assessing environmental impacts of Bt maize is discussed.
