Vascular tissues are very important for providing both mechanical strength and long-distance transport. The molecular mechanisms of regulation of vascular tissue develop- ment are still not fully understood. In this study we identified ANACoo5 as a membrane-associated NAC family transcription factor that regulates vascular tissue development. Reporter gene assays showed that ANACoo5 was expressed mainly in the vascular tissues, increased expression of ANACoo5 protein in transgenic Arabidopsis caused dwarf phenotype, reduced xylem differentiation, decreased lignin content, repression of a lignin biosynthetic gene and genes related to cambium and primary wall, but activation of genes related to the secondary wall. Expression of a dominant repressor fusion of ANACoo5 had overall the opposite effects on vascular tissue differ- entiation and lignin synthetic gene expression. The ANACoo5- GFP fusion protein was localized at the plasma membrane, whereas deletion of the last 20 amino acids, which are mostly basic, caused its nuclear localization. These results indicate that ANACoo5 is a cell membrane-associated transcription factor that inhibits xylem tissue development in Arabidopsis.
Jun ZhaoJiang-Shu LiuFu-Ning MengZhen-Zhen ZhangHao LongWen-Hui LinXiao-Min LuoZhi-Yong WangSheng-Wei Zhu
Verticillium wilt is the second serious vascular wilt caused by the phytopathogenic fungus Verticillium dahliae Kleb.It has distributed worldwide,causing serious yield losses and fiber quality reduction in cotton production.The pathogen has developed different mechanisms like the production of cell wall degrading enzymes,activation of virulence genes and protein effectors to succeed in its in fection.Cott on plant has also evolved multiple mechanisms in response to the fungus infection,including a strong production of lignin and callose deposition to strengthen the cell wall,burst of reactive oxygen species,accumulation of defene hormones,expression of defense-related genes,and target-directed strategies like cross-kingdom RNAi for specific virulent gene silencing.This review summarizes the recent progress made over the past two decades in understanding the interactions between cotton plant and the pathogen Verticillium dahliae during the infection process.The review also discusses the achievements in the control practices of cotton verticillium wilt in recent years,including cultivation practices,biological control,and molecular breeding strategies.These studies reveal that effective management strategies are needed to control the disease,while cultural practices and biological control approaches show promising results in the future.Furthermore,the biological control approaches developed in recent years,including antagonistic fungi,endophytic bacteria,and host induced gene sile ncing strategies provide efficie nt choices for in teg rated disease management.
