Physiological Function Of Arabidopsis Stt3b

Calcium and iron are necessary nutrients for plant growth and development,and they play an important role in plant growth and development.Most of proteins newly synthesized by ribosomes in living cells are inactive and need to undergo a series of precise post-translational modification processes before they can become biologically functional proteins.Glycosylation is a common post-translational modification in plant cells,and oligosaccharyltransferase?OST?plays an important role in the process of glycosylation.Staurosporin and temperature sensitive 3-like b?STT3B?is an active subunit of OST.In recent years,there are few reports about the STT3B gene,and the related reports are mainly concentrated in mammals.The function of AtSTT3B on Ca²⁺and Fe²⁺dependent growth in plant,the function of AtSTT3B on plant response to salt stress,and the exact subcellular localization of AtSTT3B in plant have not been reported.Bioinformatics methods were used to predict and analyze the AtSTT3B gene and its amino acid sequence,physicochemical property,conserved domain and transmembrane domain.By means of bioinformatics,we systematically studied the characteristics of AtSTT3B gene and its encoded protein,providing a theoretical basis for the study of AtSTT3B's physiological function and subcellular localization.We carried out a series of studies on the physiological functions of AtSTT3B in plants using the model plant Arabidopsis thaliana as the experimental material.We found that AtSTT3B had a specific regulation on Ca²⁺and Fe²⁺dependent growth in Arabidopsis roots.We also found that AtSTT3B played a very important role in plant response to external salt stress.In addition,we also found that atstt3b showed significantly inhibition phenotype on leafs in culture medium of tunicamycin.Tunicamycin is a kind of glycosylation inhibitor.To confirm that whether At STT3B was involved in the absorption and accumulation of calcium and iron in plant,we measured content of Ca and Fe in plant by Inductively Coupled Plasma?ICP?.We found that AtSTT3B gene did not participate in the absorption and accumulation of calcium and iron in plant.We studied the tissue specific expression pattern of AtSTT3B promoter by using the method of GUS histochemical staining.It was found that the AtSTT3B promoter had strong activity in the lateral root growth site and main vein.We studied the subcellular localization of AtSTT3B protein by constructing the fusion gene encoding At STT3B and green fluorescent protein?GFP?.We found that AtSTT3B located in the endoplasmic reticulum.We detected the N-glycosylation level of total proteins between Col and atstt3b in whole nutrient medium and low Ca medium with the horseradish peroxidase antibody and concanavalin A.We found that AtSTT3B did not participate in the regulation of protein glycosylation and did not participate in the regulation of protein glycosylation with low calcium stress.We detected the PDI of Col and atstt3b in whole nutrient medium and low Ca medium with PDI antibody.We found that PDI was involved in low calcium stress response and played a very important role in plant response to low calcium stress.However,we found that AtSTT3B had no effect on the process of PDI in response to low calcium stress.In summary,we studied the function of AtSTT3B on Ca²⁺and Fe²⁺dependent growth in plant,the function of AtSTT3B on plant response to salt stress,and the exact subcellular localization of AtSTT3B in plant by using the model plant Arabidopsis thaliana as an experimental material.It provides a theoretical basis for improving the function of AtSTT3B and exploring the genes of plant that adapt to poor soil of calcium and iron and high salt.It can help to solve the iron deficiency and calcium deficiency problems in plant and cultivate salt-tolerant plant.It also can help to reveal the mechanism of plant response to adversity stress.