AUTHOR=Zhan Chuang , Li Yiting , Li Han , Wang Mengru , Gong Shuangjun , Ma Dongfang , Li Yan 

TITLE=Phylogenomic analysis of phenylalanine ammonia-lyase (PAL) multigene family and their differential expression analysis in wheat (Triticum aestivum L.) suggested their roles during different stress responses

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.982457

DOI=10.3389/fpls.2022.982457

ISSN=1664-462X

ABSTRACT=<p>Phenylalanine ammonia-lyase (PAL) is a key enzyme in the phenylalanine metabolism pathway and plays an important role in plant growth and stress response. It has been widely reported in plants, but less studied in wheat. In this study, 54 <italic>PAL</italic> genes were identified in the wheat genome. Based on phylogenetic analysis, the 54 <italic>TaPAL</italic> genes were divided into four groups (I, II, III, and IV). Then, the expression levels of <italic>TaPALs</italic> under biotic stresses were analyzed by transcriptome data analysis. The results showed that 31 genes were up-regulated and one gene was down-regulated after inoculation with <italic>Fusarium graminearum</italic>, 11 genes were up-regulated and 14 genes were down-regulated after inoculation with <italic>Puccinia striiformis</italic>, and 32 up-regulated and three down-regulated genes after inoculation with powdery mildew. The expression patterns of the five <italic>TaPALs</italic> were further analyzed by qRT-PCR. After inoculation with <italic>F. graminearum</italic>, the expression levels of <italic>five TaPALs</italic> were up-regulated. However, the <italic>TaPALs</italic> (expect <italic>TaPAL49</italic>) were down-regulated when inoculated with <italic>P. striiformis</italic>. Finally, the functions of <italic>TaPAL32</italic> and <italic>TaPAL42</italic> in resistance of wheat to the stripe rust were further analyzed by virus induced gene silencing (VIGS) assays. The results showed that the disease severity of <italic>TaPAL32</italic> and <italic>TaPAL42</italic> silenced plants was higher than that of control plants at 14 days after inoculation. It indicated that these two genes played a positive role in wheat stripe rust resistance. This study provided new evidence support for the functional study of <italic>PAL</italic> genes in wheat, and provided potential application value for the breeding of wheat resistant varieties.</p>