Functional Analysis Of Nuclear Pore Complex Involved In Hydrogen Peroxide-mediated Disease Resistance In Arabidopsis Thaliana

The infection of pathogens is one of the biological stress that leads to the reduction of crop production.As a large agricultural country,China’s analysis of the interaction mechanism between pathogens and plants will be of great significance to China’s agricultural production.When plants are invaded by pathogenic bacteria,a large number of reactive oxygen species（ROS）are produced by oxidative explosion.Hydrogen peroxide（H₂O₂）is the most important signaling molecule in ROS,mediating salicylic acid（SA）related plant immune responses.The nuclear pore complex is the only channel to enter and exit the nuclear.Some studies have found that some nuclear pore proteins participate in the plant immune system and actively participate in the regulation of some gene expression.The nuclear basket of the nuclear pore complex consists of NUP62,NUP54 and TCU1 proteins.However,it is not clear whether some of the nuclear basket proteins are involved in the plant immune system.Therefore,in this study,catalase mutant cat2-1 and nuclear basket site protein mutants nup62-1,,nup54-1 and tcu1-2 of arabidopsis thaliana were used as research materials to explore the effect of nuclear basket site of nuclear pore complex on plant disease resistance and whether it affects SA related signal transmission activated by H₂O_2.And better understand the interactions between plants and microbes.Loss function NUP62,NUP54,and TCU1 impaired arabidopsis thaliana resistance to Pst DC3000 and increased susceptibility to pathogen invasion.In cat2-1 background,it was found that NUP62 and TCU1 deficiency significantly inhibited the occurrence of SA-dependent cell death induced by H₂O₂ accumulation,and attenuated the expression of PR1 and PR2 gene,suggesting that NUP62 and NUP54 are components of plant immune system.Analysis of glutathione content,antioxidant enzyme activity and ROS responsive genes of cat2-1 nup62-1,cat2-1 nup54-1 and cat2-1 tcu1-2 showed that the loss of nuclear basket function did not affect the accumulation of H₂O₂ signal.And suppresses the ROS downstream genes（WRKY75,GSTU24,etc）response,may play a role in nuclear transfer signal transmission process.SA signals into the nuclear,revealed that the loss of NUP62and TCU1 resulted in the accumulation of NPR1 in the cytoplasm and the failure of normal SA signal transmission.Therefore,I concluded that NUP62 and TCU1 proteins in the nuclear basket of the nuclear pore complex are indispensable components of the plant immune system and are involved in the downstream SA signaling of H₂O₂,which is necessary to mediate between the nuclear and cytoplasmic transport of NPR1.