Yingjun Yao

Abstract Strong UVB radiation critically restricts plant growth, yield, and distribution, while mechanisms enabling adaptation to intense UVB remain unclear. Here, we uncover that the F-box ubiquitin E3 ligase UVBT1 (also known as ETP2) is indispensable for UVB tolerance in A. thaliana. In the high-altitude Tibet accession, a distinctive 166-bp deletion in ETP2 promoter leads to the complete absence of the W-box element, thereby eliminating WRKY36-mediated transcriptional repression.

Conflicts of Interest The authors declare that they have no conflicts of interest. Supporting Information Filename Description tpj17046-sup-0001-supinfo.docxWord 2007 document , 16.7 KB Methods S1. Plant material. Methods S2. Library construction, and genome sequencing. Methods S3. Terpenoid content analysis. tpj17046-sup-0002-FigureS1.jpgJPEG image, 207.9 KB Figure S1. Estimation of the I. hylonoma genome size by K-mer analysis.

INTRODUCTION Both partial and complete submergence pose significant challenges to plants. By 2050, an estimated 450 million people could face heightened flooding stress, potentially impacting over 1.7 billion hectares of land (Arnell et al., 2014). This increased risk threatens global food security due to substantial yield losses. Addressing this issue requires a deep understanding of the molecular mechanisms underlying plant responses to hypoxia, with the goal to develop flood-tolerant crops.