Effects Of Phospholipase D On Root Nodulation And Seed Lipid Biosynthesis In Soybean (Glycine Max L.)

Soybean(Glycine max [L.] Merrill)is a dominant world oil crop;it occupies important position in the consumed composition of vegetable oil in various countries.The special function of biological nitrogen fixation it inherits have saved large nitrogenous fertilizer for agriculture in the past decades.The nodule dependent mechanism of nitrogen fixation can be helpful in other non-leguminous plants.So it is necessary to study the mechanism of biological nitrogen fixation.However,nodule formation needs a series of signal factors to be involved and regulated.Phospholpise D and its byproduct PA have been reported to actively participate in the nodule signal transduction.To explore the impact of soybean phospholpise D on the origin of nodule formation or different developmental nodule,in this research,by using the transgenic hairy roots technique we studied the impact of soybean phospholpise D on the nodule number and explain the mechanism of nitrogen fixation.In addition we also showed that the amount of phospholipids in nodule depends upon the developmental phase of the nodule.This research will pave some theoretical basis for biological nitrogen fixation.Besides,PLD have an influence on production of oil by PC and PA,so it will be very meaningful to explore the effect of PLD to oil quality and production.What's more! Related analysis of nutritional ingredients have been studied in soybean.In soybean genomes,it has 23 PLDs including 6 GmPLD?s(?1-6),5 GmPLD?s(?1-5),6 GmPLD?s(?1-6),3 GmPLD?s(?1-3)and 3 GmPLD?s(?1-3).Main GmPLDs had the different expression tendency under the treatment of wounding,salicylic acid,sodium chloride,methyl jasmonate and the infection of pest,phytophthora,phakopsora pachyrhizi.GmPLD?1 and GmPLD?5 not only had the impact in the origin of nodule formation,but they also contributed in the developmental nodule.The GmPLD?1 and GmPLD?5 over-expressed and knockdown transgenic hairy roots have very less ratio of nodule number to fresh weight of root than control.At the same time,GmPLD?1 and GmPLD?5 decreased the nitrogenase activities.The height of plants increased along with the increase of the total nitrogenase activities.GmPLD?1 and GmPLD?5 could also change the compositon of main polar lipid classes.Among them,the increase of 36:6 DGDG and 36:6 MGDG was the important reason for increased total DGDG and total MGDG.The content of DGDG and MGDG may have effect on the function of nodule factor receptor gene GmNFR.The decreased expression of GmNFR would result in wrong or lower efficient identification to nodule factors and the relative nodule number would decrease.The determination of polar lipid classes content found that total DGDG,MGDG,PG and PC kept stable levels in the different developmental phase of nodule;Whereas,the content of total PE and PS showed a minor increase along with the development of nodule,but total PA content decrease at same nodule stage.Secondly,the contents of molecular species from different phospholipids classes also had a little fluctuation,whereas the contents of molecular species from MGDG and DGDG were stable.Also,The un-regulated genes of GmPLD?1,GmPPs and single one-way transformation from PC to PA and PA to DAG in core pathway of phospholipid synthesis resulted the metabolize flux into downstream.The combined result was the little increased content of PS and PE.Suppression of GmPLD? can increase the production of oil in soybean seeds,it can also affects the expression of related genes which involve oil synthesis to increase the unsaturation in the lipids and improve the quality of oil.Suppression of GmPLD? can also improve seed quality during long-term storage which is valuable in practice.What's more,25 analysis models of nutritional ingredients have been established in soybean.