Difference Of Gene Expression In Wheat Roots Under Fron- Snffielent And Iron-deficient Conditions And Cloning Of Some CDNA Fragments

Expression difference of gene under iron-deficiency and iron-efficiency were compared between iron-efficient wheat cultivar iing-41 I and iron-inefficient wheat cultivar Sanshumai-3 by differential display Reverse Transcript PCR (DDRT-PCR) method.The results indicated that iron-deficiency stress not only induced the expression of some genes but also suppressed the expression of other genes .Under the iron-defieciency stress,the expression difference of genes in Jirig-41 I were more significant than that of Sanshumai-3,which showed that the two cultivars had different responses to the iron-deficiency stress. Northern blotting were carried out with the total RNA isolated from the root tips of wheat cultival Jing-41 I which treated by iron-deficiency stress and iron-efficiency,and the probes come from the special cDNA fragment selected from DDRT-PCR products of the same cultival .The results demonstrated that the expression of cDNA2 and cDNA3 were suppressed in iron-deficiency condition.Sequence analysis showed that cDNA3 fragment had 99%identity with the mitochondrial rpslA gene of T.aestivum,which encoding a protein involved in Cytochrome C biogenesis.Meanwhile,cDNA3 also showed about 92% identity with other plants,such as A.thaliana,mitochondrial genes that encoding protein related to cytochrome C biogenesis.It is suggested that the expression of rps 1 A gene may be suppressed by iron-defieciency stress,then resulted in the decline of cytochrome C formation.Furthermore,it would influence the respiration metabolism and the production of ATP.cDNA2- I showed strong similarity to the ATP-binding transporters (ABC transporters) gene of Arabidopsis thaliana. By the results of northern blotting. we supposed that the expression of the two genes may also be suppressed by iron-deficiency stress, but the mechanisms are unknow.