Screening And Identification Of The Leaf Senescence Mutant In Arabidopsis Under Dark-induced Carbon Starvation

Plant senescence is an age dependent process of programmed cell death at the cellular,tissue,organ and organism levels,and is the final stage of growth and development.Leaf senescence is the main form of plant aging,and is the comprehensive response of leaf cells to age information and various internal and external factors.In the process of leaf senescence,with the gradual yellowing of leaf color,the intracellular components began to enter the orderly degradation process,and cell autophagy as the main way of degradation of intracellular materials,especially in senescence leaves.Although a number of leaf senescence genes and the molecular regulation of leaf senescence have been explored,the molecular regulation network of leaf senescence remains to be further studied.Screening and identification of the dark-induced abnormol leaf senescence mutant in Arabidopsis has been studied in this research.The main results and conclusions are as follows:1.Constructed a dark carbon starvation induced senescence system,and the effectiveness of the system was tested by inducing the classical autophagy gene defect mutants atg5-1 and atg7-3 produce an early senescence phenotype.2.The senescence-related phenotype of mutant amp1-1 induced with the constructed dark carbon starvation system,which identified the early aging phenotype of amp1-1;and further explored the mutation site in the mutant,and studied the the relationship between AMP1 protein and autophagy protein ATG8 e and the accumulation of ATG8 e and ATG8-PE in amp1-1,found that AMP1 protein co-locates with autophagy ATG8 e,and the accumulation of ATG8 and ATG8-PE in amp1-1 mutant was different from that of wild type.Futhermore,constructed AMP1 gene-replicating plants,which demonstrated that a series of senescence-related phenotypes exhibited by amp1-1 mutants were caused by the deletion of AMP1 gene.3.The gain-of-function mutant abs3-1D was mutated by EMS,and senescence phenotype induced with dark carbon starvation systerm,thereby screened the suppressor of abs3-1D mutants which can reverse the early senescence phenotype of abs3-1D,and further confirmed the aging phenotype.This laid the foundation for the discovery of new leaf senescence regulators and the discovery of complex leaf senescence regulatory pathways.In this study,we constructed a reasonable dark carbon starvation-induced senescence system,and used this system to identify the senescence-related phenotypes of the existing mutant materials and screen the senescence-related mutants,which provide basis for finding new molecular regulators of leaf senescence and elucidating plant senescence pathways.