Study On The Molecular Mechanism Of Peanut(Arachis Hypogaea L.) Embryo Abortion Mediated By Calcium

Seeds is the most economic index of peanut ( Arachis hypogaea L.) production and the early development of embryo is the important stage for the yield and quality of peanut.For many years now , there has been a general problem existing in peanut production areas in the red and yellow soil region of south China,which barepods and falles in yield of peanut resulting from deficient calcium in soil.Baseing on the measures and comparisions between water culturing and field experiment in Pingtan(Fujian province) in different levels of calcium, the project deeply and systematically dealt with the experiment about DDRT and proteome in order to reveal the molecular biology mechanism of peanut embryo abortion mediated by calcium. Some valuable results were as follows:1. Revealed the mode of the peanut plant growth and development and empty pod occurrence. In field experiment, leaves and stems of peanut were influenced gently, but pods were influenced badly by calcium. Lacking of calcium caused changes of photosynthetic product and ill-filled pods and empty pods increasing, which significantly lowered the yield. But under calcium deficiency stress in water culture ,both vegetatives and pods of growth in water culture were influenced seriously.In our opinions, the peanut materials for molecular experiment from the field experiment were more suitable than that from water culture .The field production managements against empty pods were also presented.2. Succeeded firstly in conducting the research of DDRT of peanut early embryoes between in deficient and sufficient levels of calciumion .8 differentially displayed cDNA fragment were obtained and four of them (L#, 1#, 3#, 8#)were confirmed by reverse northern dot blot and RT-PCR . B1AST was used to search the NCBInr database.The result were as follows: Fragment L# shows high homology with the ATP-dependent Clp protease ATP-binding subunit CIpX from Arabidopsis thaliana (thale cress) .We registered it in Genebank(AY517932); Fragment 8s shows 87% homology with the MADS box protein GHMADS-1 (MADS-1) mRNA complete cds ( AF538965 ) from Gossypium hirsutum L.. Fragment 8# was also registered in Genebank( AY572857) by us. Fragment 1# and 3# could not be found homologous with any valuable sequences,thus,maybe a new gene.Basing on above,we cloned the cDNA of peanut MADS genes and the structural characteristics was preliminarily analysized firstly.The cDNA of peanutMADS genes showed good homology with the MADS box gene or amino acid seguences from many plants.3. Established firstly a preliminary 2-D electrophoresis system for proteins from peanut early embryoes with two calcium levels. The peptide mass fingerprinting(PMF) of Seven differentially expressed proteins were got by MALDI-TOF-MS. Mascot was used to search the protein database.The results were as follows: 4# protein.which up-regulated in embryoes from sufficient calcium group, showed high homology with chloroplast envelope membrane 70 kDa heat shock-related protein from Spinacia oleracea L.6# protein(down-regulated in embryoes with sufficient calcium) showed high homology with (ATPB)ATP synthase beta chain from Hevea brasiliensis L.And 7# protein (disappeared in embryoes in sufficient calcium group)was considered similar to Actin 97 from Solarium tuberosum. 2#\3# protein showed some homology with Glyceraldehyde 3-phosphate dehydrogenase\ Isocitrate dehydrogenase.All the results indicated:the molecular mechanism for embryoes abortion mediated by calcium may be relevant to some genes, which controlling assenergy transfering (ATP synthesis) oxidoreduction system endomembrane system and cytoskeleton structure system ,transcripted or expressed unnomally.