Comparative genomic analysis of the PAL genes in five Rosaceae species and functional identification of Chinese white pear

Abstract

Phenylalanine ammonia lyase (PAL) plays an important role in the biosynthesis of secondary metabolites regulating plant growth response. To date, the evolutionary history of the PAL family in Rosaceae plants remains unclear. In this study, we identified 16 PAL homologous genes in five Rosaceae plants (Pyrus bretschneideri, Fragaria vesca, Prunus mume, Prunus persica, and Malus × domestica). We classified these PALs into three categories based on phylogenetic analysis, and all PALs were distributed on 13 chromosomes. We tracked gene duplication events and performed sliding window analysis. These results revealed the evolution of PALs in five Rosaceae plants. We predicted the promoter of the PbPALs by PLANT CARE online software, and found that the promoter region of both PbPAL1 and PbPAL3 have at least one AC element. The results of qRT-PCR analysis found that PbPAL1 and PbPAL2 were highly expressed in the stems and roots, while expression level of PbPAL3 was relatively low in different tissues. The expression of PbPAL1 and PbPAL2 increased firstly and then decreased at different developmental periods of pear fruit. Among them, the expression of PbPAL1 reached the highest level 55 days after flowering. Three PbPALs were induced by abiotic stress to varying degrees. We transfected PbPAL1 and PbPAL2 into Arabidopsis thaliana, which resulted in an increase in lignin content and thickening of the cell walls of intervascular fibres and xylem cells. In summary, this research laid a foundation for better understanding the molecular evolution of PALs in five Rosaceae plants. Furthermore, the present study revealed the role of PbPALs in lignin synthesis, and provided basic data for regulating lignin synthesis and stone cells development in pear plants. . 2019. Comparative genomic analysis of the PAL genes in five Rosaceae species and functional identification of Chinese white pear. PeerJ 7:e8064 http://doi.Chapple C. 2015. Manipulation of guaiacyl and syringyl monomer biosynthesis in an Arabidopsis cinnamyl alcohol dehydrogenase mutant results in atypical lignin biosynthesis and modified cell wall structure.

Genome-Wide Analysis and Expression Profiling of the Phenylalanine Ammonia-Lyase Gene Family in Solanum tuberosum

“…In the present study, there were two exons within most of the 14 PAL members (78.6% of cases). As can be seen from the clustering of Figure 3 b, StPAL proteins with similar exon/intron structures are more likely to cluster together, which is consistent with the results of PAL gene family analysis in most plants, such as maize [ 33 ], pear [ 34 ] and Juglans regia [ 35 ]. Among them, the intron/exon organization of StPAL7-StPAL14 is very similar.…”

Validation of Reference Genes for Studying Different Abiotic Stresses in Oat (Avena sativa L.) by RT-qPCR

“…PAL is one of the key enzymes during the synthesis of the well-known stress hormone, SA [ 22 ]. Elevated PAL activity or mRNA level was found in different plant species after exposure to various abiotic stresses [ 23 , 24 , 25 ]. The relative expression level of PAL was normalized with the two most stable reference genes and the least stable reference gene in oat according to the applied stress factor.…”

Phenylalanine Ammonia-Lyase (PAL) Genes Family in Wheat (Triticum aestivum L.): Genome-Wide Characterization and Expression Profiling

“…Wheat faces various types of biotic and abiotic stresses. It has been suggested that phenylalanine ammonia-lyase (PAL) genes are essential for plant growth, development, adaptation, and mitigation responses to various environmental and pathogens stresses by producing secondary metabolites regulating plant growth response [11,58,59]. Phenylpropanoids are plant-based organic compounds, which are produced from the amino acids phenylalanine and tyrosine.…”