Functional Dissection Of Amino Acid Deficency Related Gene,SOL1,in Arabidopsis

The protein is the important component for the organism,providing fundamental factors for life growth and development.As short of amino acid supply,proteins synthesis will be disorder,even result in organism death.In the present study,we screened a suppressor of LEW1 mutant,sol1-1,through ethyl methane sulfonate(EMS)mutagenesis in Arabidopsis.Then,the map-based cloning identified the mutant gene was At1g64790.And,the last base of the 52 th intron of wild type gene was substituted for G with A,which induced the transcript false spliced and translation process abortion.The bioinformatics analysis revealed that SOL1 is a homolog of yeast protein GCN1(general control non-derepressible-1)in Arabidopsis.Previous studies have proved that the GCN1 and GCN20,together with t RNA,to activate GCN2.Furthermore,activated GCN2 promoted the phosphorylation of eIF2?(eukaryotic initiation factor 2?),and initiated translation process for amino acid deficiency responding.In this study,we aimed to identify the interaction between SOL1 and GCN2in Arabidopsis.All the plant materials,including wild type,sol1-1,sol1-2and gcn2,were treated by chlorsulfuron(CHL)for imitating the amino acid stress.One week after chlorsulfuron treatment,sol1-1,sol1-2 and gcn2 were exhibited significant etiolated,especially in new leaves.The result revealed that SOL1 and GCN2 were involved in the response of amino acid deficiency.After ultraviolet irradiation,the level of phosphorylation of eIF2? have a significant reduction in mutant sol1-1 and gcn20,which indicated that both SOL1 and GCN20 participate GCN2 activation.Additionally,exogenous plant hormones,NAA and 2,4-D,could result in later flowering in mutant sol1-1.The mutants,includingsol1-1,sol1-2,gcn2 and gcn20,all were sensitive to ABA,which indicted that SOL1 and GCN2probably take part in plant hormone regulation.Our results revealed that the SOL1-GCN2-eIF2 nodes is an important pathway for plant anti-stress and growth regulation.This finding will provide reference for the related studies in other plants.