RESUMO
As water-soluble, natural pigments, anthocyanins are responsible for the red, purple and blue colors of many flowers, which attract pollinators to spread pollen. The colors of flowers are also essential for plants to survive in the nature and become one of the most significant characteristics of ornamental plants. In the booming floriculture industry, to produce various flower colors could increase the richness of natural colors, but it is still difficult to breed flowers with coveted blue color. The diversity of flower color is mainly determined by the types and contents of anthocyanins and their derivatives. The synthesis of delphinidin pigments is the key factor for breeding blue flowers. However, there are no structural genes in many plants to biosynthesize delphinidin pigments. Blue flowers are successfully created by genetic engineering in recent years. In this paper, using common ornamental plants as examples, we review the mechanism of plant flower coloration from the aspects of the key factors affecting the synthesis of delphinidin pigment and the production strategies of blue flowers based on the regulation of anthocyanin metabolism. Different strategies of molecular breeding could provide opportunities to improve colors of other floriculture plants and to develop anthocyanin-rich economic crops, such as colored cotton with blue fibers.
Assuntos
Antocianinas , Metabolismo , Flores , Regulação da Expressão Gênica de Plantas , Engenharia Genética , Pigmentação , GenéticaRESUMO
Objective To investigate the characteristics of brain network based on brain electrical activity induced by somatosensory electrical stimulation,and to provide a theoretical basis for further understanding the mechanism of brain neural plasticity induced by somatosensory electrical stimulation.Methods Ten healthy subjects were selected and a somatosensory electrical stimulation experiment was constructed based on the directed transfer function (DTF).In the experiment,the DTF causal connection matrixes of the 32-channel EEG data of Delta,Theta,Alpha and Beta bands were obtained under the somatosensory electrical target and non-target stimulation,and the differences of clustering coefficient and global efficiency between two stimulation states were contrasted based on graph theory.Results Under the target stimulation and non-target stimulation states,the regions with stronger DTA causal connections were mainly concentrated in FCz,Cz,CPz and Pz channels.The causal connection intensity under target stimulation state was greater than that of non-target stimulation.Also,in the Delta,Theta,and Alpha bands,the clustering coefficient under the target stimulation state was significantly higher than that in the non-target stimulation state (P＜0.05).In the Delta and Theta bands,the global efficiency of the target stimulation state was significantly higher than that of the non-target stimulation state (P＜0.05).Conclusions Somatosensory electrical stimulation can activate and induce EEG brain networks.In the target stimulation state,the role of the parietal lobe in the EEG causal network is enhanced,which helps to induce attention to specific brain region plasticity,and thus realizing the nerve rehabilitation in the brain regions of interest.While in the non-target stimulation state,the synergistic interactions between brain regions were enhanced,which helps to activate and induce a wide range of associations in the whole brain network,so as to promote the global neural activity in the brain.