A recently discovered tea [Camellia sinensis (L.) O. Kuntze] cultivar can generate tender shoots in winter. We performed comparative proteomics to analyze the differentially accumulated proteins between winter and spring tender shoots of this clonal cultivar to reveal the physiological basis of its evergrowing character during winter. We extracted proteins from the winter and spring tender shoots (newly formed two leaves and a bud) of the evergrowing tea cultivar “Dongcha11” respectively. Thirty-three differentially accumulated high-confidence proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF / TOF MS). Among these, 24 proteins had increased abundance while nine showed were decreased abundance in winter tender shoots as compared with the spring tender shoots. We categorized the differentially accumulated proteins into eight critical biological processes based on protein function annotation including photosynthesis, cell structure, protein synthesis & destination, transporters, metabolism of sugars and polysaccharides, secondary metabolism, disease/defense and proteins with unknown functions. Proteins with increased abundance in winter tender shoots were mainly related to the processes of photosynthesis, cytoskeleton and protein synthesis, whereas those with decreased abundance were correlated to metabolism and the secondary metabolism of polyphenolic flavonoids. Biochemical analysis showed that the total contents of soluble sugar and amino acid were higher in winter tender shoots while tea polyphenols were lower as compared with spring tender shoots. Our study suggested that the simultaneous increase in the abundance of photosynthesis-related proteins rubisco, plastocyanin, and ATP synthase delta chain, metabolism-related proteins eIF4 and protease subunits, and the cytoskeleton-structure associated proteins phosphatidylinositol transfer protein and profilin may be because of the adaptation of the evergrowing tea cultivar “Dongcha11” to low temperature and light conditions. Histone H4, Histone H2A.1, putative In2.1 protein and protein lin-28 homologs may also regulate the development of winter shoots and their response to adverse conditions.

The flooding of tea plantation caused by natural rainfall is a common natural disaster, which has adverse effects on the soil quality of tea plantation, the growth of tea trees, and the yield and quality of tea. This article systematically studied the multidimensional effects of natural rainfall (flood conditions) on tea plantation soil for the first time. In this study, the physicochemical properties, heavy metals, and microbial communities of tea plantation soil samples were analyzed at six time points after natural rainfall (flood conditions) at 0, 15, 18, 21, 24, and 27 days. The results showed that natural rainfall (flood conditions) had a significant impact on soil nutrients and heavy metal concentrations in tea plantations. With the extension of flooding time, compared with the pre-flooding control (0 days), soil pH, organic matter, available potassium, available phosphorus, alkali-hydrolyzable nitrogen, and the concentrations of eight heavy metals first increased and then decreased with prolonged flooding, and the concentrations of all heavy metals were lower than the limits of soil environmental quality standards. After flooding, Proteobacteria was the dominant group of bacterial community, and Acidobacterita, Chloroflexi, and Actinobacteriota were also abundant. The fungal community is dominated by Ascomycota and Basidiomycota. Soil components were significantly correlated with microbial community, in which organic matter, available potassium, and pH value had the greatest impact on bacterial community, while fungal community was mainly affected by available potassium, organic matter, Cr, and As. In general, natural rainfall (flood conditions) will reduce the content of nutrients and heavy metals in tea plantation soil and change the soil microbial community structure, which provides a scientific basis for evaluating the impact of natural rainfall on tea plantation soil health.