AUTHOR=Lee Hyeong-Un , Shim Sangrea , Chung Mi Nam , Lee Taeyoung , Park Won , Kim Tae Hwa , Lee Kyo Hwui , Woo Koan Sik , Nam Sang-Sik , Kim Moon Young , Lee Suk-Ha 

TITLE=Transcriptomic analysis for the gamma-ray-induced sweetpotato mutants with altered stem growth pattern

JOURNAL=Frontiers in Genetics

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2024.1419399

DOI=10.3389/fgene.2024.1419399

ISSN=1664-8021

ABSTRACT=<sec><title>Introduction</title><p>Sweetpotato faces breeding challenges due to physiological and genomic issues. Gamma radiation is a novel approach for inducing genetic variation in crops. We analyzed the transcriptomic changes in gamma ray-induced sweetpotato mutants with altered stem development compared with those in the wild-type 'Tongchaeru’ cultivar.</p></sec><sec><title>Methods</title><p>RNA sequencing analyses were performed to identify changes in the expression of genes related to stem development.</p></sec><sec><title>Results</title><p>Transcriptomic analysis identified 8,931 upregulated and 6,901 downregulated genes, including the upregulation of the auxin-responsive <italic>SMALL AUXIN UP RNA</italic> (<italic>SAUR</italic>) and three <italic>PHYTOCHROME INTERACTING FACTOR 4</italic> (<italic>PIF4</italic>) genes. <italic>PIF4</italic> is crucial for regulating the expression of early auxin-responsive <italic>SAUR</italic> genes and stem growth in <italic>Arabidopsis thaliana</italic>. In the mutant, several genes related to stem elongation, including <italic>PIF4</italic> and those involved in various signaling pathways such as auxin and gibberellin, were upregulated.</p></sec><sec><title>Discussion</title><p>Our results suggest that gamma ray-induced mutations influence auxin-dependent stem development by modulating a complex regulatory network involving the expression of <italic>PIF4</italic> and <italic>SAUR</italic> genes, and other signaling pathways such as gibberellin and ethylene signaling genes. This study enhances our understanding of the regulatory mechanisms underlying stem growth in sweetpotato, providing valuable insights for genomics-assisted breeding efforts.</p></sec>