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.
BACKGROUND
Peanut (Arachis hypogaea L.) is an important oilseed crop whose yield is threatened by various abiotic stresses. Glycosyltransferases are crucial for diverse plant functions, including the regulation of plant growth and development, biotic and abiotic stress response, and the biosynthesis of secondary metabolites. However, the mechanism of glycosyltransferases relates to abiotic stresses remains unclear in peanut.
RESULTS
In this study, we isolated a novel gene, AhIRX7, from a salt-tolerant mutant of peanut. The expression of AhIRX7 was strongly induced by NaCl and PEG6000. Overexpression of AhIRX7 led to increased, whereas silenced of AhIRX7 resulted in decreased tolerance of peanut seedlings to salt and drought stresses. Compared to wild-type (WT), the overexpression lines showed significantly increased chlorophyll fluorescence parameters and reduced photodamage under salt and drought stress. Their activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were markedly enhanced, while the accumulation of superoxide anion (O2-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly reduced. In contrast, AhIRX7-silenced lines exhibited opposite trends in SOD, POD, and CAT activities, as well as MDA accumulation. Consequently, overexpression of AhIRX7 improved the regulation of photosynthesis, the dynamics of stomatal opening and closing under salt and drought stress in Arabidopsis plants.
CONCLUSIONS
Overall, this study indicated that AhIRX7 gene functions in enhancing drought and salt stresses in peanuts and Arabidopsis, which may serve as a candidate gene for use in improving abiotic stress resistance in crops.
Yanyan Tang, Xiaoting Li, Wenlin Wang et al.· BMC Plant Biology· 0 citations
Together, these findings provide a foundation for functional characterization and useful information for future research on the role of SlPHD family members in plant abiotic stress tolerance.
Tayeb Muhammad, Tao Yang, Haitao Yang et al.· Planta· 0 citations
Rosa roxburghii is a perennial flowering shrub producing edible fruits with exceptional nutritional and antioxidant properties, yet its cultivation and productivity are severely constrained by drought stress. Squamosa promoter-binding protein-like (SPL) transcription factors are key regulators of plant development and stress responses. However, their roles in coordinating early drought perception with downstream metabolic adaptation in R. roxburghii remain largely unexplored. Here, we systematically identified 16 SPL genes in the R. roxburghii genome and characterized their evolutionary relationships, structural features, and expression patterns under drought stress. Among them, RrSPL3 was rapidly induced during the early phase of drought stress and localized to the nucleus. Functional analyses demonstrated that overexpression of RrSPL3 enhanced drought tolerance in both Arabidopsis thaliana and R. roxburghii, as evidenced by maintenance of chlorophyll content, enhanced antioxidant enzyme activity, and reduced membrane damage. Combined DAP-seq, transcriptomic, EMSA, and dual-luciferase analyses further demonstrated that RrSPL3 directly activates RrFLS1 under drought stress by binding to the GTAC-containing motif in its promoter, leading to increased flavonol accumulation and enhanced reactive oxygen species scavenging. Together, our findings uncover a previously unrecognized SPL-FLS-flavonol regulatory module that links early drought signaling to metabolic antioxidant defense, providing mechanistic insight and potential molecular targets for improving drought resilience in R. roxburghii and horticultural species.
Hong Nan, Jie Wen, Yiming Song et al.· Horticulture Research· 0 citations
