AUTHOR=Li Xin-Miao , Zhai Han-Han , An Xiu-Hong , Zhang He , Zhang Xueying , Wang Pengfei , Chen Haijiang , Tian Yi 

TITLE=PpSAUR5 promotes plant growth by regulating lignin and hormone pathways

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1291693

DOI=10.3389/fpls.2024.1291693

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Peach (<italic>Prunus persica</italic>) has a high nutritional and economic value. However, its overgrowth can lead to yield loss. Regulating the growth of peach trees is challenging. The small auxin-up RNA (<italic>SAUR</italic>) gene family is the largest family of auxin-responsive genes, which play important roles in plant growth and development. However, members of this gene family are rarely reported in peach.</p></sec><sec><title>Methods</title><p>In this study, we measured leaf area, chlorophyll and lignin content to detect the role of <italic>PpSAUR5</italic> on growth through transgenic <italic>Arabidopsis</italic>.</p></sec><sec><title>Results</title><p><italic>PpSAUR5</italic> responds to auxin and gibberellin, promoting and inhibiting the synthesis of gibberellin and auxin, respectively. The heterologous transformation of <italic>PpSAUR5</italic> in <italic>Arabidopsis</italic> led to enhanced growth of leaves and siliques, lightening of leaf color, decrease in chlorophyll content, increase in lignin content, abnormalities in the floral organs, and distortion of the inflorescence axis. Transcriptome data analysis of <italic>PpSAUR5</italic> overexpression and wild-type lines revealed 854 differentially expressed genes (DEGs). GO and KEGG analyses showed that the DEGs were primarily involved in biological processes, such as cellular processes, metabolic processes, response to stimuli, and catalytic activity. These genes were mainly enriched in pathways, such as phenylalanine biosynthesis, phytohormone signaling, and MAPK signaling.</p></sec><sec><title>Discussion</title><p>In summary, these results suggested that <italic>PpSAUR5</italic> might regulate tree vigor by modulating the synthesis of auxin and gibberellin. Future studies can use <italic>PpSAUR5</italic> as a candidate gene to elucidate the potential regulatory mechanisms underlying peach tree vigor.</p></sec>