| Plants turn sunlight into bioavailable energy,which is the foundation of all species survival.During whole life cycle of plants,they are often exposed to the pathogen threat.The immune response to infection generally comes at the expense of plant growth.Plant growth and development are strongly associated with the extent and proportion of mitosis and endocycle,which are the two types of cell cycle.Besides,environmental cues impact these intrinsic programs at least partly through the regulation on cell cycle machinery.A tradeoff between the requirement of internal growth and development program and environmental stimuli including pathogen infection is essential for plants to survival and production.A larger number of regulators of immunity and growth are involved in the coordination of this complex regulation network.According to current functional genomics and interactomics research in Arabidopsis,this study found some potential regulators of this regulation for genetic analysis.It will help us to further understand the plant-pathogen interactions.The plant immune system consists of multiple layers of responses targeting various phases of pathogen infection.This study provides evidences showing that two responses,one controlling stomatal closure and the other mediated by immune receptor proteins,can be regulated by the same proteins but in an antagonistic manner.The heat shock protein HSC70,while previously known as a negative regulator of stomatal closure,is a positive regulator of R mediating immune responses.In contrast,a calcium binding protein BON1 promotes pathogen-triggered stomatal closure in addition to and independent of its previously known negative role in SNC1 regulation.BON1 likely regulates stomatal closure through inhibiting HSC70.This study thus reveals new functions of BONI and HSC70 that have opposite effects on immunity.It exemplifies the complexity in immunity regulation and suggests that immune receptors may guard positive regulators functioning at stomatal closure control.Plants have a complex network to sense endogenous signals and environmental cues in order to catch according flowering time for successful production.This study found a plant immunity regulator MOS1 is physically associated with the FLC promoter,and this association is dependent on a FRI complex component SUF4.In addition,another FRI complex component FES1 is essential for MOS1 mediating flowering time control.Although MO S1 and a SAC component MAD 1 antagonistically regulate flowering time,this study found this antagonism is not dependent on vernalization pathway.This study reveals a plant immunity regulator is directly involved in the regulation of flowering time,which suggests an involvement of immune responses in the timing of reproductive transition.Cell cycle control is fundamental to plant growth and development as well as environmental responses.Both immunity responses and cell cycle control affect expression of thousands genes through various pathway.This study confirmed an interaction between two immunity and cell cycle regulators,MOS1 and TCP 15,providing evidences suggesting they regulate the endoreduolication and immune responses together.MOS1 makes the G2/M transition smoothly to prevent endocycle entry,and this function can be replaced by high expression of TCP15.Besides,both MOS1 and TCP 15 are essential for SNC1 mediated immune response.Thus MOS1 and TCP15 may form a complex,to enhance the transcriptional activation function of TCP15,mediating the regulation together.It reveals the cell cycle regulation and immune responses sharing some regulators,and this pattern may help plants balancing environmental cues and internal programs efficiently. |
PDF Full Text Request