*2.3. Cloning and Sequence Analysis*

We obtained the CDSs of *PlNCEDs* from transcriptome data. The amino acid sequences of *PlNCEDs* were deduced using ORF Finder (https://www.ncbi.nlm.nih.gov/orffinder/) (accessed on 8 December 2022). A phylogenetic tree was constructed using MEGA 7.0 software with the neighbor-joining method, applying bootstrap analysis with 1000 replicates, and iTOL v6 (https://itol.embl.de/) (accessed on 13 January 2023) was used to optimize the trees. The conserved domains were predicted by National Center for Biotechnology Information (NCBI) online software (https://www.ncbi.nlm.nih.gov/Structure/cdd/wrpsb.cgi) (accessed on 13 January 2023). The protein physicochemical properties were analyzed using the Expasy ProtParam tool (http://web.expasy.org/protparam/) (accessed on 8 December 2022).

Using total RNA as the template, 1st-strand cDNA was synthesized using 3' RACE adaptor primers. According to the CDSs of *PlNCEDs*, we designed the specific outer and inner primers (Supplementary Table S1) to amplify the 3' untranslated region (UTR) sequences of *PlNCEDs* using 3'-Full RACE Core Set with PrimeScript™ RTase Kit (Takara, Dalian, China). The miRNA binding sites of 3' UTR sequences were predicted using MiRanda software.

Genomic DNA was extracted using the Plant Genome DNA Rapid Extraction Kit (Aidlab, Beijing, China). According to the known verified intronless sequences, three specific primers were designed, namely, SP1, SP2, and SP3 (Supplementary Table S1), to amplify the 5' end sequences of *PlNCEDs* containing 5' UTR and promoter regions using the Genome Walking Kit (Takara, Dalian, China). *Cis*-acting elements of the promoter were analyzed using PlantCARE.
