The Transcriptional and Post-Transcriptional Regulation in Perennial Creeping Bentgrass in Response to Γ-Aminobutyric Acid (GABA) and Heat Stress

Persistent high temperature inhibits plant growth and development. The gamma-aminobutyric acid (GABA) plays a key role in heat tolerance in plants. The increase in endogenous GABA level induced by exogenous GABA effectively alleviated heat damage in creeping bentgrass. Global investigation into rnRNAs and miRNAs found that the regulation of HSFs pathways and enhanced carbon metabolism, biosynthesis of amino acids, and plant hormone signal transduction were important adaptive response to heat stress. GABA-induced heat tolerance was closely related to phenylpropanoid biosynthesis, further improved HSFs pathways, and the upregulation of CAD3, ACS, AER, and CA1 associated with lignin and lipids biosynthesis, photosynthesis and water use, and antioxidant defense. Dramatic changes of miR398s, cca-miR156b, aly-miR159c-3p, and ata-miR408-3p had a close correlation with heat-survival. The especial vvi-miR845c, ama-miR156, and other novel miRNAs such as novel-24223, novel-2964, and novel-10098 could be involved in GABA-regulated heat tolerance. The integrated analysis of mRNAs and miRNAs facilitates uncovering of adaptative response in perennial plants under high temperature environmental condition and also reveals that GABA acting as a critical plant growth regulator induces heat tolerance in creeping bentgrass involved in physiological, transcriptional, and post-transcriptional regulation. Particularly, current results provide some key candidate genes and miRNAs for further investigating their potential roles in heat tolerance in non-model plants.