Comparative Multi-Omics of Tender Shoots from a Novel Evergrowing Tea Cultivar Provide Insight into the Winter Adaptation Mechanism.

Abstract

Tea (Camellia sinensis [L.] O. Kuntze) tree is a perennial plant in which winter dormancy is an important biological adaptation to environmental changes. We discovered and reported a novel tea tree cultivar that can generate tender shoots in winter several years ago, but the molecular mechanism for this unique phenotype remains unknown . Here, we conducted comparative transcriptomics, proteomics and metabolomics along with phytohormone quantitation between the winter and spring tender shoots to investigate the physiological basis and putative regulatory mechanisms of its evergrowing character during winter. Our multi-omics study has led to the following findings. Gibberellin (GA) levels and key enzymes for GA biosynthesis and the signal transduction pathway were increased in the winter shoots, causing the ABA/GA content ratio to decrease, which might play a key regulatory role in maintaining normal growth during winter. The abundance of proteins, genes and metabolites involved in energy metabolism was all increased in winter shoots, indicating that energy is critical for continuous growth under the relatively weak-light and low-temperature environment. Abiotic resistance-related proteins and free amino acids were also increased in abundance in the winter shoots, which possibly represents an adaptation response to winter conditions. These results allowed us to hypothesize a novel molecular mechanism of adaptation for this unique tender shoot evergrowing in winter.