Analysis Of Upstream Regulation Of IRKT1 In Malus Xiaojinensis And The Evolution Of S-nitrosylation Sites

Iron is one of the essential elements for the growth of fruit trees,and it is very important to study the efficient use mechanism of the iron in apple rootstocks.Here,using the high-efficiency genotype Malus Xiaojinensis and low efficiency genotype Malus Baccata as materials,we investigate the responses of IRT1 to the iron-deficiency.Preliminary data revealed that a TATA-box was inserted into the promoter region of IRT1,which increased the transcription activity of IRT1 and enhanced the absorption efficiency of iron.To uncover the mechanism of this enhancement,we screened out a transcription factor TFIID(MDP0000939369),that could bind to the TATA-box in the promoter of IRT1,using the yeast-one-hybrid assay,and verified the binding specificity by EMS A.Our data demonstrated that the inserted TATA-box promoted the IRT1 transcription activity through its specific binding with transcription factor TFIID,and played essential roles in regulating the anti-iron-deficiency mechanism of plants.The S-nitosylation sites of IRT1 protein(iron-regulated transporter 1)are regularly differentiationed in angiosperm.Here we selected the representative plants in mechanism ?,including Arabidopsis thaliana,Lycopersicon esculentum and Malus Xiaojinensis as materials and using the point mutation and transgenetic methods to investigate the function of S-nitosylation for iron transportation by IRT1.The results showed that:the S-nitrosylation sites of IRT1 was involved in the response of plant iron deficiency,and the subnitrification degree of total protein of the root protein which of the iron deficiency is higher than that in normal iron treatment,the normal iron treatment with the releaser is higher than that in the iron deficiency with the inhibitor.These results indicates that NO can respond to plant iron deficiency stress by regulating the S-nitrosylation of protein.