Research Of PIN Gene Function Encoding Auxin Efflux Transporters In Ceratopteris Pterioides

In the course of plant growth and development,auxin forms a concentrati on gradient,which determines the position of organs and their basic construction.PIN protein is the efflux transporter of auxin,which asymmetrical distribution o n cytoplasmic membrane leads to the specific flow of auxin.The function and e volution of many PIN genes have been studied,but the PIN gene in Parkeriacea e yet.Ceratopteris pterioides which is a quasi pattern specie in the molecular bi ology study of Parkeriaceae and has significant different fertile leaves,is an ide al material for the research of PIN gene function.In the first part of this paper,we discussed the effects of auxin and its tran sport inhibitors on spores germination of Ceratopteris pterioides.In this research we found that exogenous auxin over a certain concentration inhibited the germi nation of spores,the inhibitors NPA,TIBA and BFA also.The inhibition effect of NPA was the most obvious.However,IAA can antagonize the inhibition effe c of NPA and TIBA.Further studies have shown that the addition of IAA could significantly reduce the inhibition of NPA within 12 hours of the spores cultiva tion,but the antagonistic effect decreased obviously when IAA was added at 24 hours of the spores cultivation,and it did not function completely at 48 h.It can be seen that both NPA and IAA may have a certain influence on the important events,such as gravity response,cell nuclear migration and cell division,in diff erent periods during the spores germination of Ceratopteris pterioides.In the next part,we had cloned three PIN genes from Ceratopteris pterioide s.Our analysis shows that the length of their complete coding regions is 2328 bp,2037bp and 2118 bp,and the number of amino acids encoded by these genes is776,679 and 706 respectively.The encoded proteins which contain two transme mbrane domains and have a the hydrophilic ring more than 120 amino acids,are all typical long hydrophilic ring type PIN proteins.The phylogenetic analysis of PIN gene in Pteridophyte is further analyzed and found the above three genes belong to PINJ,PINL and PINM of PIN types in Pteridophyte.In the research of genetic transformation,we first constructed the 35S::GFP carrier.We found that the carrier can make the cell fluorescence through gene g un bombardment and transient expression of onion epidermis.On this basis,we further constructed the 35S::PIN-GFP fusion expression carrier which had verified by sequencing.Above all,our research shows that auxin influenced the growth and develop ment of Ceratopteris pterioides which contains several PIN genes which has lon g hydrophilic ring and has important biological functions in this specie.