A Survey of Enhanced Cold Tolerance and Low-Temperature-Induced Anthocyanin Accumulation in a Novel Biotype.

is a warm-season turfgrass that is extensively used in landscaping, sports fields, and golf courses worldwide. Uncovering the low-temperature response mechanism of can help to accelerate the development of new cold-tolerant cultivars, which could be used to prolong the ornamental and usage duration of turf. A novel biotype, YueNong-9 (YN-9), was collected from northeastern China for this study. Phenotypic measurements, cold-tolerance investigation, and whole-transcriptome surveys were performed on YN-9 and LanYin-3 (LY-3), the most popular cultivar in Southern China. The results indicated the following: YN-9 has longer second and third leaves than LY-3; when exposed to the natural low temperature during winter in Guangzhou, YN-9 accumulated 4.74 times more anthocyanin than LY-3; after cold acclimation and freezing treatment, 83.25 ± 9.55% of YN-9 survived while all LY-3 leaves died, and the dark green color index (DGCI) value of YN-9 was 1.78 times that of LY-3; in YN-9, there was a unique up-regulation of (), (), and () expressions, as well as a unique down-regulation of () expression, which may promote anthocyanin biosynthesis, transport, and accumulation. In conclusion, YN-9 exhibited enhanced cold tolerance and is thus an excellent candidate for breeding cold-tolerant variety, and its unique low-temperature-induced anthocyanin accumulation and gene responses provide ideas and candidate genes for the study of low-temperature tolerance mechanisms and genetic engineering breeding.