Differential Analysis On Allergenic Proteins Of Pollen In Different Populus Germplasms

Poplar is not only the main afforestation tree species of fast growing and high-yield forest,shelter trees and so on,but also it is a common green tree species in China.Flowering period of poplar was from March to April,producing a large number of pollen grains by male plants every year and have the potential of allergy.Therefore,it is significant to provide a theoretical basis for the research of the selection of the low sensitive poplar germplasm and control of the plant allergic diseases by exploring different pollen allergenicity in difference poplar germplasms.In this paper,8 species of the main cultivated poplar tree species in north China were selected as the research materials,carrying out the basic characteristics of pollen germination rate and pollen tube length in different poplar germsplasms,and the difference of allergenic proteins of pollen in different poplar germplasms and predicting the potential allergenic proteins in the mature pollen of Populus tomentosa was using two-dimensional electrophoresis and real-time quantitative PCR.The main results are as followed:Pollen germination experiment showed that the pollen viability of P.deltoides cl.‘2KEN8',P.deltoides cl.‘Nanyang' and P.nigra var.italica was higher,followed by P.deltoides cl.‘Zhonghuai 2',P.simonii and P.deltoides × P.maximowiczii,however,the viability of P.deltoides cl.‘Zhonghuai 1',P.deltoides × P.cathayana cl.‘Senhai 2' was the worst,and the difference of pollen viability were significant among the different germplasms.Proteome analysis showed 5 allergenic proteins were missing expressed in the seven germplasms with the identified 28 potentially allergenic protein of P.deltoides cl.‘2KEN8' as reference.The number of allergenic proteins of P.deltoides cl.‘Zhonghuai 1' and P.deltoides cl.‘Zhonghuai 2' was the most,followed by P.deltoides cl.‘Nanyang',P.deltoides × P.cathayana cl.‘Senhai 2' and P.deltoides × P.maximowiczii cv ‘Eridano',while the number of allergenic proteins of P.simonii and P.deltoides × P.maximowiczii was the least.Moreover,thedifference expression of the remaining 23 allergenic proteins were analyzed,the expression of allergenic proteins in P.deltoides cl.‘Zhonghuai 2',P.deltoides cl.‘Nanyang' and P.deltoides× P.maximowiczii were higher than other germplasms,while the expression of P.deltoides × P.cathayana cl.‘Senhai 2' and P.simonii was significantly lower than other germplasm.qRT-PCR analysis showed that the expression of seven allergenic protein coding genes in P.deltoides cl.‘Zhonghuai 2',P.deltoides cl.‘Nanyang' and P.deltoides × P.maximowiczii were higher than P.deltoides × P.cathayana cl.‘Senhai 2' and P.simonii,which also verified the result of differences proteome analysis.Proteomic analysis of P.tomentosa mature pollen showed that 242 protein spots were successfully identified,34 proteins were predicted to be the potential allergenic proteins of mature pollen in Populus.The analysis of expression level,transcription level and different tissue expression pattern of allergenic proteins suggested that Ole e 1 protein and LEA protein was expressed higher that other allergenic proteins.P.deltoides cl.‘2KEN8' and P.tomentosa have the same eight allergenic proteins;cluster analysis showed that 62 allergenic proteins can be divided into three categories of Populus mature pollen,these results indicate that the different germplasm of Populus may cause the same allergic reaction.The pollen germination characteristics of different poplar species were compared in this study,and qualitative and quantitative analysis of the allergenic proteins of different germplasms pollen was carried out,and found the allergenic proteins was low expression in P.simonii,P.deltoides cl.‘Zhonghuai 1' and P.deltoides × P.cathayana cl.‘Senhai 2',which can be considered as one aspect of the breeding of poplar varieties with low sensitivity.In addition,different poplar germplasms pollen have the same allergenic proteins and prediction of potential allergenic proteins of Populus can be divided into three categories,to lay a theoretical foundation for the future prediction of cross allergenic reaction and the conprehensive design of allergy diagnosis methods.