ABSTRACT
ABSTRACT Phytoene synthase (PSY) is the rate-limiting enzyme for carotenoid biosynthesis. To date, several studies focused on PSY genes in the context of abiotic stress responses. In this study, two phytoene synthase encoding genes, IbPSY1 and IbPSY2, were identified from a published transcriptome and bioinformatic analysis showed that they shared conserved domains with phytoene synthases from other plants. The IbPSY1 gene was cloned and carefully characterized. Digital gene expression profiling (DGE) showed that the highest transcription level of IbPSY1 was in young leaves, and the lowest level was in stems. In vivo expression levels of IbPSY1 under abiotic stress were observed to be highest in stems at day 11. Over-expression of IbPSY1 in Escherichia coli and yeast cells endowed the cells with better growth under salt and drought stress than the control cells. This study demonstrated that IbPSY1 not only played an important role in vivo, but also in E. coli and yeast to improve tolerance to salinity and drought stress. Thus, IbPSY1 may be aid in the development of transgenic plants with enhanced stress tolerance.
Subject(s)
Stress, Physiological , Ipomoea batatas , Gene Expression , Plants, Genetically ModifiedABSTRACT
This study investigated the effects of ATP-sensitive potassium channels on the expression of P21,P27 and leptin. The expression of receptor of ATP-sensitive potassium channels (sulphony-lurea receptor,SUR) mRNA in the preadipecytes and ieptin mRNA was detected by PCR after rat preadipocytes were treated with the opener (diazoxide) or inhibitor (glibenclamide) of ATP-sensitive potassium channels during the process of inducing differentiation. The expression of P21 and P27 in preadipocytes treated with diazoxide or glibenclamide was assayed by Western blot. The results showed that the expression of SUR2,not SURI was detected in adipose tissue,preadipocytes and adipocytes. After treatment of preadipocytes with diazoxide,the expression levels of P21 and P27 were obviously higher than those in control group,but the expression levels of P21 and P27 in glibenclamide-treated group were lower than those in control group. During the process of inducing differentiation,the expression of leptin mRNA in preadipocytes treated with diazoxide was increased greatly,but the expression of leptin mRNA in glibenclamide-treated group decreased obviously. It was concluded that ATP-sensitive potassium channels might be involved in the proliferation and dif-ferentiation of rat preadipocytes by changing the expression of P21,P27 and leptin.