*4.3. Expression Patterns of CsWRKY7 in Tea Plant*

Total RNA was extracted from the different tissues of 'Longjing 430 using QIAGEN RNeasy Mini Kit (Qiagen, Hilden, Germany). The reverse transcription reaction was carried out by FastKing gDNA Dispelling RT SuperMix RT Reagent Kit (TIANGEN, Beijing, China). Real-time PCR was performed on an optical 384-well plate with a LightCycler 480 machine (Roche, Sussex, UK). Each reaction contained 5 µL of SYBR Green I Master Mix (Roche Diagnostics), 1.0 µL cDNA samples, and 0.4 µM of each gene specific primer in a final volume of 10 µL. The *glyceraldehyde-3-phosphate dehydrogenase* (*GAPDH*) gene (accession no. FS952640) was used as an internal control. The expression levels were computed by the formula 2−∆∆Ct [49,50].

## *4.4. Subcellular Location Analysis*

Using gateway cloning technology, *CsWRKY7* full-length cDNA sequence without terminator codon was recombined into pH7FWG2 vector, containing the enhanced green fluorescent protein (eGFP) reporter gene, to generate 35s::*CsWRKY7*-eGFP fusion construct. Then, the recombinant plasmid (35s::*CsWRKY7*-eGFP) and the control (35s::GFP) were transformed into *Agrobacterium tumefaciens EHA105* by freeze–thaw approach [51]. The confirmed bacteria were grown in yeast extract peptone (YEP) medium (pH = 7.4) at 28 ◦C until optical density at λ = 600 nm (OD600) to 1.0. This medium added with bacteria was centrifuged at 4000 rpm for 10 min. the sediment was resuspended with suspension buffer containing 10 mM MgCl2, 10 mM MES, and 100 µM acetosyringone (AS), with OD<sup>600</sup> adjusted to 0.4. The suspension was infiltrated into well-developed *N. benthamiana* leaves. After infiltration, the tobacco plant was cultured in darkness for 48 h at 24 ◦C and then put in light for half an hour. The GFP signal was observed by a confocal microscopy. Additionally, cellular localization of the CsWRKY7-eGFP proteins in lateral roots of transgenic Arabidopsis plants was also observed by confocal microscopy.
