Overexpression of PlPAT1, a GRAS transcription factor from Paeonia lactiflora, enhances salt stress tolerance in transgenic tobacco
TL;DR
It is demonstrated that PlPAT1 functions as a positive regulator of salt stress tolerance, likely through modulating osmotic balance and enhancing reactive oxygen species scavenging capacity.
Abstract
Soil salinization poses a significant threat to agricultural productivity worldwide, including the cultivation of Paeonia lactiflora . Understanding the molecular mechanisms of salt stress response and identifying key salt-tolerant genes are essential for breeding resilient varieties. The GRAS family of transcription factors is known to regulate plant growth, development, and abiotic stress responses; however, its role in P. lactiflora remains poorly characterized. In this study, we identified a novel GRAS transcription factor from P. lactiflora , designated PlPAT1 , based on its homology to Arabidopsis GRAS members. Under salt stress, PlPAT1 expression was up-regulated in leaves and stems but down-regulated in roots. Subcellular localization revealed that PlPAT1 protein localizes to both the nucleus and cytoplasm. Transgenic tobacco lines overexpressing PlPAT1 exhibited enhanced salt tolerance, accompanied by increased chlorophyll content, elevated levels of soluble sugars and proteins, and higher activities of antioxidant enzymes (SOD, POD, CAT). In contrast, malondialdehyde (MDA) and hydrogen peroxide accumulation were significantly reduced compared to wild-type plants. Our results demonstrate that PlPAT1 functions as a positive regulator of salt stress tolerance, likely through modulating osmotic balance and enhancing reactive oxygen species scavenging capacity. These findings highlight the potential of PlPAT1 as a candidate gene for improving salt tolerance in plants and provide a genetic resource for the utilization of saline-alkali land.