Tea plant is susceptible to low temperature, while the
cold injury recovery mechanisms of
tea leaves are still unclear. Windbreak has an effective and gradient range of protecting
tea plants.
Tea plants with increasing cold damage degree have varying recovery status accordingly, which are the ideal objects for investigating the
cold injury recovery mechanisms of
tea leaves. Here, we investigated the transcriptome and
phytohormone profiles of
tea leaves with different
cold injury degrees in recovery (adjacent to the windbreak), and the levels of
chlorophylls,
malondialdehyde, major
phytohormones as well as the activities of
peroxidase (POD) and
superoxide dismutase (SOD) were also measured. The results showed the content of total
chlorophylls and the activity of POD in mature
tea leaves gradually decreased with the distance to windbreak, while SOD showed the opposite. The major
phytohormones were highly accumulated in the moderately cold-injured
tea leaves. The biosynthesis of
abscisic acid (ABA) was enhanced in the moderate cold damaged
tea leaves, suggesting that ABA plays an important role in the cold response and resistance of
tea plants. The transcriptomic result showed that the samples in different rows were well discriminated, and the pathways of plant-pathogen interaction and
flavonoid biosynthesis were enriched based on KEGG analysis. WRKY, GRAS and NAC were the top classes of
transcription factors differentially expressed in the different cold-injured
tea leaves. Thus, windbreak is effective to protect adjacent
tea plants from cold wave, and
phytohormones importantly participate in the
cold injury recovery of
tea leaves.