Cloning And Functional Analysis Of Stress-responsive Gene OsIDP1 In Rice

As a populous country,average arable land in China is far less than most countries.Rice is the staple food for most people.Rice production is considered to be the foremost link in national production owing to the significance in social stability and development.With the deterioration of environment,increasing rice yield is becoming more and more difficult.Despite traditional breeding has the potential to cultivate stress-resistant varieties,there are still numerous obstacles,including complex time-consuming operations.In contrast,genetic engineering attracts more attentions with shorter cycle and strong purposiveness.Intrinsically disordered proteins contains at least one intrinsically disordered region and they have been reported to be invloved in multiple cell processes,such as stress response,signal cascade,protein interaction,transcription regulation and cell cycle control.Great progress has been made in rice abiotic stress response,many stress resistance mechanisms and signal transduction pathways have been well elucidated,yet there are still many molecular mechanisms to be explored.The research of intrinsically disordered proteins in plant stress is relatively few and the underlying stress response mechanisms need to be explored in depth.To understand stress response mechanisms and find new stress-responsive genes,a multiple stress-responsive gene was selected on the basis of microarray under heat,cold and drought treatments at different developmental stages.This gene was named OsIDP1 on account of an about 30-residue-long intrinsically disordered region in the C-terminal.The c DNA is 960 bp and the open read frame(ORF)is 522 bp.The encoded protein is predicted to be 18.06 k Da with p I=9.68.The promoter region analysis using Plant CARE showed that this gene contains multiple cis-regulatory elements responding to abiotic stresses.Besides,q RT-PCR analysis revealed that this gene was induced by multiple abiotic stresses.In order to further characterize the function of OsIDP1 in stress response,four vectors were constructed,including D-163+1300:OsIDP1(over/antisense expression),D-163+1300:OsIDP1-GFP and p CAMBIA3301:P-OsIDP1,and corresponding transgenic rice plants were cultivated.GUS activity assay suggested that OsIDP1 had expression in coleoptile,root,stem,leaf,spike,embryo but anther.Furthermore,OsIDP1 was induced by multiple abiotic stresses.Subcellular localization indicated that OsIDP1 is a membrane protein,presumably related to substance transport or signal cascades.Preliminary experimental findings showed that overexpression transgenic plants were hypersensitive to salt stress while antisense expression transgenic plants were hyposensitive.Likewise,overexpression transgenic plants appeared to more sensitive to drought.These results still needed to be confirmed.Additionally,overexpression transgenic plants were hypersensitive to ABA while antisense expression transgenic plants were hyposensitive.