Genome-wide Characterization Of GLPs Gene Family And Functional Preliminary Analysis Of PutGLP37 In Puccinellia Tenuiflora

Germin and germin-like proteins(GLP)are common glycoproteins in plants.They play a key role in plant development and in response to adversity.In this paper,bioinformatics and molecular biology methods were used to identify the members of PutGLPs gene family and analyze the function of PutGLP37 in Puccinellia tenuiflora.Fifty-three genes encoding GLPs were identified in the genome.Based on phylogenetic analysis,137 GLPs from Puccinellia tenuiflora,Arabidopsis thaliana,Oryza sativa and Hordeum vulgare were divided into five groups.Members of PutGLPs gene family were distributed in groups 1,3 and 4.Most members of PutGLPs gene family are closely related to members of GLPs gene family from rice and barley.Chromosome location and genome collinearity analysis showed that,except PutGLP37,PutGLPs gene family members are located on all chromosomes of Puccinellia tenuiflora genome(Chromosomes 1,2,3,4,5,6,and 7).Among them,14 pairs of genes with repeated sequences,and there are 4 gene pairs with repeated fragments on chromosome 2,6,7.The members of PutGLPs gene family of same groups showed great similarities in gene structure and conserved motif.The results of RT-qPCR showed that PutGLPs were expressed in roots,stems,leaves,sheaths and flowers of P.tenuiflora.Most of the PutGLPs were highly expressed in roots,stems and flowers of P.tenuiflora,while only PutGLP32 was highly expressed in leaves.Under stresses(200 mmol/L NaCl,75 mmol/L Na2CO3,100 mmol/L NaHCO3 and 4?),PutGLPs were mostly up-regulated in the roots and leaves of P.tenuiflora,suggesting that PutGLPs may be involved in the response to salt,alkali,and low temperature stress.PutGLP37 was screened by a full-length cDNA yeast library.By structural prediction,it was found that PutGLP37 contained Box A,Box B and Box C.Box B and Box C constituted the Cupin domain and had a signal peptide at the N terminal.Subcellular localization analysis showed that PutGLP37 was localized to the cell membrane and cytoplasm.Under salt stress(1 mol/L NaCl and 1.3 mol/L NaCl),alkali stress(15 mmol/L Na2CO3 and 26 mmol/L NaHCO3),osmotic stress(1.8 mol/L Sorbitol),oxidative stress(2.8 mmol/L H2O2),and heavy metal stress(CdCl2,KCl,CuCl2,CoCl2,ZnCl2,BaCl2,CaCl2,AlCl3,MnCl2,FeCl3 and NiSO4),The tolerance of the transgenic yeast strain PutGLP37 to stress was significantly higher than that of the control yeast strain.PutGLP37 may be involved in the response to saline-alkali stress,oxidative stress,osmotic stress and heavy metal stress.In conclusion,PutGLPs gene family may play an important role in the stress response of P.tenuiflora,and provide new evidence for further understanding the molecular regulation mechanism of the stress response of Puccinellia tenuiflora.