*4.9. Measurement of Na<sup>+</sup> Content*

For each sample, a total of 0.05 g of dry tissues power were weighed and immersed in 4 mL concentrated nitric acid with 2 mL 30% H2O<sup>2</sup> overnight, and then were decocted with temperature gradient (60 ◦C for 1 h, 120 ◦C for 1 h, 160 ◦C for 1 h, 190 ◦C until the solution was clarified) using a graphite digestion instrument (DigiBlock ED54, Beijing, China). The content of extracted Na<sup>+</sup> was measured by inductively coupled plasma-mass spectrometry (ICP-MS) (iCAP RQ, Thermo Fisher Scientific, 168 Third Avenue, Waltham, MA, USA) after acid catching, constant volume and filtration with three biological replicates per sample.

#### *4.10. RNA Extraction and Quantitative Real-Time PCR*

Total RNA was extracted using the Total RNA Miniprep kit (Axygen, Hangzhou, China) following the manufacturer's instructions. First-strand cDNA was synthesized using the ReverTra Ace qPCR-RT kit (Toyobo, Osaka, Japan) as instructed by the manufacturer, using 2 µg of total RNA for each reaction. qRT-PCR analyses were performed using SYBR Premix Ex Taq (Takara, Kusatsu, Japan) and gene-specific primers on a CFX96TM real-time system. Three or four biological replicates were performed for all experiments. The primers used are listed in Table S5 in the Supplementary Materials.

#### *4.11. Quantification and Statistical Analysis*

Quantification analyses on all the measurements were conducted in GraphPad Prism 8. Significant differences were determined with Student's *t*-test and Duncan's new multiple range tests.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/ijms23158818/s1.

**Author Contributions:** Project administration, Q.Q. and G.Z.; funding acquisition, J.X., Q.Q., G.Z; supervision, G.Z.; writing—original draft preparation, J.W., Y.L., J.X.; investigation, J.W., Y.L., J.N., M.C., J.C.; data curation, J.W., Y.L., X.L., Z.Z., D.L.; methodology, L.Z., J.H., D.R., Z.G., L.S., G.D., Q.Z., Q.L., S.Y., X.C., S.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by grants from the National Natural Science Foundation of China (31901483, 31861143006 and 32188102), Nanfan special project of CAAS (ZDXM06), Special Support Program for Distinguished Talents of CAAS (NKYCLJ-C-2021-015) and Zhejiang Province (2019R52031), and Hainan Yazhou Bay Seed Laboratory (B21HJ0220-02).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

