Transcriptome Analysis Of The Barley Shrunken Endosperm Mutant Seg4

Barley(Hordeum vulgare L.)is one of the oldest crops in the world.Previous studies mainly focused on breeding,quality analysis,agronomic traits and resistance of barley.Few studies reported on characterization of barley seeds.The traits of barley shrunken endosperm were reported in 1975,and so far,only a few of genes controlling the characteristics of shrunken endosperm in barley have been identified.To date,the molecular mechanism of seg4 has not been revealed.In this study,we selected the wild type barley BM42(Bowman)and shrunken endosperm mutant BM3(the descendent of BM42 and BGS380 seg4 after 5 cycles backcrosses;BM3 and BM42 are considered as near-isogenic lines)for transcriptome analysis to uncover its molecular mechanism.The main results are as following:1.Analysis of SNPs between BM42 and BM3 revealed that the chromosome 6H contains most number of SNPs.2.We detected 148,251,and 1,847 DEGs(differentially expressed genes)between BM42 and BM3 at 10,15,20 days after anthesis(DAA),respectively.A total of 2,087 unique DEGs were identified across the three time-points.3.KEGG Pathway enrichment analysis of DEGs between BM42 and BM3 at 10,15 and 20 days after anthesis found that the metabolism of starch and sucrose was enriched at 20 DAA.This indicated that the metabolism of starch and sucrose began to be active from 15 to 20 days after anthesis.4.The results of DEGs' principal component analysis showed that the difference between BM42 and BM3 was significant at 15 and 20 DAA;5.Cluster analysis of expression pattern of the 2,087 DEGs found that there were 440 DEGs present in the BM42 and BM3;6.The protein sequences of the 440 DEGs which had been selected in the previous analysis were obtained.These protein sequences were used for prediction of protein interaction network.Twelve genes were selected by prediction.These 12 DEGs encode cytochrome P450 superfamily protein,heat shock protein,dihydroxy-acid dehydratase,glutathione S-transferase family,histone-lysine N-methyltransferas,DNA mismatch repair protein MutS,indole-3-acetaldehyde oxidase and alcohol dehydrogenase.These genes were most likely involved into regulating shrunken endosperm.