Physiological Changes And Gene Expression Of Soybean(Glycine Max L.)in Response To Iron Deficiency

Glycine Max l.is an important and one of the five main crops in the world.Iron(Fe)is an important nutrient of most organisms,has adverse effects on plant growth and development when shortage.Iron supply directly affects the yield and quality of soybean during its growth and development.In this study,multiple varieties of soybean were selected for treatment of iron deficiency to analysis the changes of phenotypic,physiological indicators,antioxidant enzyme activity,and expression of some iron-metabolism-related genes.The transcriptome sequencing were carried out using Heinong 51 and Suinong 37 under iron deficiency.The results are as follows:1.Compared with the control,the iron content,chlorophy content and antioxidant enzyme activity decreased in soybean varieties treated with iron deficiency,and the above indexes of each variety changed significantly,indicating that there were significant differences in the tolerance to iron deficiency among the tested soybean varieties.The plant height of the tested soybean varieties was less effected by iron deficiency and showed no significant difference between treatment and the control(P<0.05).The number of primary roots and lateral roots were increased in all of the tested soybean varieties,and showed significant difference between treatment and the control in Dongnong 54,Heinong 53 and Henong 75(P<0.05).2.Iron deficiency treatment resulted in a decrease in the pH value of the culture solution of all tested soybean varieties except Suinong 31,with no significant difference from the control(P<0.05).The FCR activity increased in soybean roots of Heinong 51,Suinong 37,Hefeng 51,Suinong 36 and Hefeng 47 under iron deficiency,and the FCR activity was significant difference in Heinong 51(P<0.05).Bromocresol purple staining showed that there was obvious rhizosphere acidification of soybean treated with iron deficiency.The determination of organic acids showed that the content of organic acids increased in the roots of Suinong 37 and Heinong 51treated with iron deficiency,including citric acid,tartaric acid,oxalic acid,formic acid and pyruvate.The results showed that the increase of FCR activity and organic acid secretion was related to rhizosphere acidificatio of soybean caused by iron deficiency.3.The analysis of gene expression by qRT-PCR on different soybean varieties showed that H~+-ATPase was up-regulated by iron deficiency in Suinong 31.The expression of bHLH47 gene was up-regulated in Suinong 37 and Dongnong 54 by iron deficiency,and the highest expression was in Suinong 37.RIP1 was up-regulated in Suinong 31 and Dongnong 54 by iron deficiency.4.Comparative transcriptome analysis was performed on iron-deficient tolerant variety Suinong 37 and sencitive variety Heinong 51 under iron deficiency.A total of88,648 transcripts and 3,188 differentially expressed genes were obtained,of which1,313 DEGs were up-regulated and 1,875 DEGs were down-regulated.The DEGs are mainly involved in cell function,binding and catalytic functions,cell processes and metabolic processes.The most significant difference was the process of photosynthesis between these two varietiesis influenced by iron deficiency.