Characteristic Of Adenosine Sulfrylase And 3'-Phospho-adenosine-5'-PhosphoSulfate Reductase Genes In Rice

Sulfur is an essential macroelement in the development of plant, affecting the process of growth regulation, detoxification, defence and stress tolerance, as well as quality of crop. It is reported that the soil in more than 70 countries in the world, including China, lack of sulfate or tend to lack of sulfate. This is becoming severe gradually. As a result, it has damaged crop production.Rice is one of the most important food crops in the world, which has become a model plant for cereal genome research and molecular breeding, based on the progress of whole genome sequencing and rapid development of biotechnology .It is important to investigate the assimilation pathways and regulation mechanism of rice sulfate. This will help us to understand the function of sulfur in development and quantity /quality of crop.In this work, adenosine sulfrylase gene (ATPS) and 3'-phosphoadenosine -5'-phosphosulfate reductase gene (PAPR) were cloned both from the root and the leaf of rice. The 1104 bp of full-length cDNA sequence of adenosine sulfrylase gene was amplified, which is homologous to the expected sequence of open reading frame of ATPS gene, with the similarity of 98%. While the full-length cDNA sequence of 3'-phosphoadenosine- 5'-phosphosulfate reductase gene amplified is also similar to the expected sequence of 1582 bp, with identity of 100%.Semiquantitative RT-PCR showed that concomitance the deficient stress of sulfate, ATPS gene became up-regulation but PAPRgene down- regulation in the root of rice; however, ATPS gene up-regulation but PAPRgene constant in the leaf of rice. Meanwhile, under the high concentration of sulfate stress ATPS gene was down regulated but PAPR gene up regulated in the root of rice; while ATPS gene down-regulated but PAPR gene was constant in the leaf of rice.In order to explore sulfate assimilation pathways and orientation of rice, we constructed plant recombinant expression vector 326-GFP-1 by subcloning the open reading frame of the PAPR gene into the transient expression vector 326-GFP. A prokaryotic recombinant expression vector pET-1 was further constructed by subcloning the PAPR gene open reading frame into the prokaryotic expression vector pET-28a (+). The expression of this gene produced a protien of 52KDa, which was purified for testing immunology and biology activites in the future.