Analysis Of The Expression Of EgrCT And EgrDREB2A To Abotic Stresses In Eucylptus Grandis

Abiotic stresses conditions such as drought, low temperature, high salinity, drought,have adverse affects on the plant growth and development. Under stress surroundings,the balance of physiologl and metabolism in plant cells was broken up. And destroyswere brought to the cell structure, making growth stunted and even death to the plant. Tosurvive in these harmful conditions, plants evolved complicated systems to adapt tostress conditions. There are a large number of genes which involved in the response;And study of these genes will be meaningful to reveal the molecular mechanisms of plantresistance toabiotic to stresses. With genetic engineering methods and plant molecularassistant breeding way, the ability of plant resistant to adverse conditions will beimproved. In this study, we screened2EST from the mRNA SSH library constructed at4?. According to analysis of bioinformation about two genes, these two genes weremapped to two genes in Eucylptus grandis, One encodes a protein belonging to thefamily of transcription factors DREB2class, we named it as EgrDREB2A. And foranother, it has still not been annotated, so we called it EgrCT just because it may berelated to cold tolerance in Eucylptus grandis.The expressions of EgrCT and EgrDREB2A in different tissues were analyzed withRT-PCR method.The result showed that both EgrCT and EgrDREB2A mainly expressedin leaves, but weakly in stems and roots. qRT-PCR analysis of the results of EgrCT andEgrDREB2A in different low temperature (0,2,4,6,8?) and time course treatmentat4?(0.5,2,6,12,24,48h) showed that both of these genes were induced under lowtemperatures.The expression of EgrCT reached the highest level at2?, and has someoscillation when seedlings was treated with different time at4?.However, theexpression of EgrDREB2A increased with the time of treatment delayed. Under saltstress, EgrCT gene expression was significantly inhibited while EgrDREB2A wasinduced. When treated with ABA, the result showed that EgrCT gene expression wasalmost hardly affected, compared with the control, implying the roles it played wasindependent with ABA. The circadian clock also effects the expression changes on EgrCT and EgrDREB2A, they both were induced in daylight but inhibited in night.Transient expression of protein of EgrCT and EgrDREB2A merged with GFP usinggene gun in onion cells showed that the protein they conded were mainly located in thenuleas. For the EgrCT, we use the Yeast two-hybrid systems to study its transcriptionalactivity in vitro, but the result showed there is no obvious transcriptional activity in vitro.