A <i>SMALL AUXIN UP-REGULATED RNA</i> Gene Isolated from Watermelon (<i>ClSAUR1</i>) Positively Modulates the Chilling Stress Response in Tobacco via Multiple Signaling Pathways
<i>SMALL AUXIN UP-REGULATED RNA</i> (<i>SAURs</i>) genes are acknowledged as auxin-responsive genes that play crucial roles in modulating adaptive growth under abiotic stress conditions. Low temperatures constitute a primary limiting factor that significantly impairs the deve...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Horticulturae |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2311-7524/11/1/52 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <i>SMALL AUXIN UP-REGULATED RNA</i> (<i>SAURs</i>) genes are acknowledged as auxin-responsive genes that play crucial roles in modulating adaptive growth under abiotic stress conditions. Low temperatures constitute a primary limiting factor that significantly impairs the development, growth, and fruit quality of watermelon plants during the winter and spring seasons. Despite their potential importance, <i>SAURs</i> have not yet been thoroughly investigated or characterized in watermelon. In this study, we identified a positive regulator of the chilling stress response among watermelon <i>SAURs,</i> designated as <i>ClSAUR1</i>. Subcellular localization analysis demonstrated that the protein is directed to both the nucleus and cytoplasm. Quantitative real-time PCR (qRT-PCR) analysis indicated that <i>ClSAUR1</i> is ubiquitously expressed across various watermelon tissues, with pronounced expression in the roots and leaves. Moreover, qRT-PCR and promoter::β-glucuronidase (<i>GUS</i>) staining assays revealed that the expression of <i>ClSAUR1</i> is significantly upregulated in response to exogenous abscisic acid (ABA) and chilling stress. The overexpression of <i>ClSAUR1</i> in tobacco lines was contrasted and analyzed, revealing an increased tolerance to chilling stress. This was evidenced by a reduced degree of wilting and chlorosis compared to wild-type (WT) plants. Furthermore, the overexpressed lines showed reduced reactive oxygen species (ROS) accumulation and increased antioxidant enzyme activity. The qRT-PCR results further indicated that the expression levels of genes associated with abscisic acid (ABA), antioxidant enzymes, and CBF–COR cold-responsive pathways were upregulated in the transgenic tobacco lines. This study provides new insights into the role of <i>ClSAURs</i> in enhancing the cold resistance of watermelon. |
|---|---|
| ISSN: | 2311-7524 |