Effects Of Iron On Tomato Seedling Growth And Cloning And Analysis Of Citrate Transporter Gene SlFRD3

Iron participates in a series of life activities,such as plant respiration and photosynthesis,which is essential for plant to exert normal physiological and metabolic function.Although the iron content in the soil is very rich,but because of its very low solubility in the form of oxides exist,is not conducive to plant absorption and utilization,so plant iron deficiency is a common problem in agriculture.Iron deficiency not only hinders plant growth,affects the accumulation of iron in grains,interferes with the tolerance and adaptability of plants to soil conditions,but also directly affects human iron nutrition levels through the food chain.To clarify the balance of iron in the plant,so as to solve the problem of plant iron deficiency is a key issue in improving human and animal iron nutrition problems.Tomato is an important vegetable crop widely cultivated around the world.Therefore,the research of iron-rich tomato has become the hot direction of the world.In this study,the effects of different iron contents on the physiological and morphological indexes of tomato seedlings including iron content,chlorophyll content,root length,root activity,proline and malondialdehyde were studied.The results showed that under different iron concentration nutrient solution,the morphological and physiological differences of tomato seedlings were obvious.Iron deficiency treatment(0 ?mm EDTA-Fe)significantly inhibited the growth of tomato seedlings,and with the increase of stress time,the effect of inhibiting growth was more obvious;While the tomato seedlings treated with high iron(200mM EDTA-Fe)were significantly larger than those of normal treatments(100mM EDTA-Fe)and iron deficiency treatments,and were better in physiological and morphological indexes.In this study,the specific primers were designed according to the coding region of SIFRD3 gene by querying NCBI.The gene was identified by cloning.The full length of the cDNA is 1984bp and contains an open reading frame of 1578bp,encoding 525 amino acids.In this study,the expression of SIFRD3 in tomato roots,stems,leaves,flowers and fruits was also studied by fluorescence quantitative PCR.The results showed that the expression of SIFRD3 was the highest in tomato roots,followed by leaves,stems,mature fruits(38-40 days after anthesis),flowers,young fruits(8-10 days after anthesis),expanded fruit(28-30 days after anthesis)and green fruit(18-20 days after anthesis).The differences of the expression of SIFRD3 in different parts of tomato with different iron concentration were studied by fluorescence quantitative PCR.Bioinformatics analysis showed that the molecular formula was C2613H4170N652O703S21,the molecular weight was 56641D,the isoelectric point was 9.19,which was soluble protein;no signal peptide site,the stability coefficient was 29.38,was stable protein;the average hydrophilic coefficient was 0.652,Membrane domain is a transmembrane protein.Containing two MatE(PF01554)(158-259,316-475)and one Polysacc synt C(PF14667)(212-341)domain.The secondary structure of the SIFRD3 protein predicted a 48.76%alpha-helix,8.95%beta-turn,and 20.38%random curl.Through the analysis of amino acid sequence and phylogenetic tree,it was found that the relationship between tomato SlFRD3 and Pan Nali tomato,potato,pepper,tobacco,American tobacco and hairy tobacco was similar,but with the biological model of rice and Arabidopsis thaliana Amino acid sequence is not a branch,the relationship is far,indicating that the SlFRD3 protein and Arabidopsis thaliana FRD3,rice OsFRDL1 and other possible functional processes are somewhat different.In this study,we cloned an 1813 bp promoter fragment of SlFRD3 gene to construct SlFRD3p-PBI121 fusion expression vector.The results showed that there were many important cis-acting elements in the promoter region of SIFRD3 gene,which was analyzed by using plant predictive analysis software.In this sequence,there are two kinds of stress-related interaction elements in addition to the TATA-box which can make the transcription accurate start,and the core promoter elements that control the starting frequency CAAT-box.6 and hormone-related action elements,which are involved in the reaction of jasmonic acid,ethylene,gibberellin and salicylic acid,respectively;and a number of components related to tissue specificity,such as participation and Regulation of endosperm expression,as well as some of the maximal activator-mediated activating elements,which laid the foundation for the further transformation of the subcellular localization of SIFRD3 gene and the regulation research of SlFRD3 gene promoter.