Abstract
Activation and enhancement of heat shock factor (HSF) pathways are important adaptive responses to heat stress in plants. The γ-aminobutyric acid (GABA) plays an important role in regulating heat tolerance, but it is unclear whether GABA-induced thermotolerance is associated with activation of HSF pathways in plants. In this study, the changes of endogenous GABA level affecting physiological responses and genes involved in HSF pathways were investigated in creeping bentgrass during heat stress. The increase in endogenous GABA content induced by exogenous application of GABA effectively alleviated heat damage, as reflected by higher leaf relative water content, cell membrane stability, photosynthesis, and lower oxidative damage. Contrarily, the inhibition of GABA accumulation by the application of GABA biosynthesis inhibitor further aggravated heat damage. Transcriptional analyses showed that exogenous GABA could significantly upregulate transcript levels of genes encoding heat shock factor HSFs (HSFA-6a, HSFA-2c, and HSFB-2b), heat shock proteins (HSP17.8, HSP26.7, HSP70, and HSP90.1-b1), and ascorbate peroxidase 3 (APX3), whereas the inhibition of GABA biosynthesis depressed these genes expression under heat stress. Our results indicate GABA regulates thermotolerance associated with activation and enhancement of HSF pathways in creeping bentgrass.
Highlights
Persistent high temperature in summer seriously affects the normal growth and development of plants
Heat-stressed plants with GABA pretreatment (H+GABA) had a 22% increase in GABA content than heat-stressed plants without GABA application (H)
The GABA and 3-mercaptopropionic acid (3-MPA) had no significant effects on relative water content (RWC) and electrolyte leakage (EL) during 30 d of the non-stress condition (Figure 2)
Summary
Persistent high temperature in summer seriously affects the normal growth and development of plants. Heat stress has become one of the main abiotic stresses limiting crop production and the quality of ground cover plants due to the aggravation of global warming [1,2]. Creeping bentgrass has become the first choice for establishing high-quality turf, such as the putting green in a golf course, because of its fine texture, charming color, and stoloniferous habit [4,5]. It is of great significance to find an effective way to improve heat tolerance of creeping bentgrass in summer. The application of plant growth regulators (PGRs) for improving heat tolerance of plants has many advantages including low cost and environmental risk, simple operation, and stable effect [6].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
