Integrative Transcriptome and Single-cell Sequencing Reveal the Antagonistic Regulation of TS1 and SK1 in Maize (Zea mays) Sex Differentiation
YIN Jia-Le1, NI Wen-Ting3, ZHANG Wen-Bo1, WANG Xue-Wen1, LI Jian-Rui2,*, MIAO Xing-Fen1,*
1 College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing 163319, China; 2 Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; 3 College of Agriculture, South China Agricultural University, Guangzhou 510642, China
Abstract：Jasmonic acid, as an important endogenous signaling molecule, determines sex differentiation by inducing programmed death of pistil primordia during maize (Zea mays) flower development. However, its precise regulatory network is still unclear. In this study, the key genes TASSEL SEED 1 (TS1) and SILKLESS 1 (SK1) that regulate sex differentiation by jasmonic acid were used as targets to obtain functional deletion mutants by gene editing, and phenotypic and transcriptome analyses were performed. The results showed that the ts1 mutant showed feminization of male flowers, and the sk1 mutant showed loss of female filaments. Transcriptome analysis showed that ts1 mutation downregulated the expression of genes involved in the jasmonic acid signaling pathway, thereby promoting pistil development. The sk1 mutation might enhance the jasmonic acid signaling pathway and inhibit pistil formation. Integrative analysis based on published single-cell RNA-seq data revealed that 93 key genes were activated in the ts1 mutant during the critical period of floral organformation and sex determination (floret meristem-stage 1 (FM-S1) to FM-S3), which may be involved in the pistil inhibition process. GO enrichment analysis revealed pathways related to floral organ development and identified potential downstream target genes of jasmonic acid regulating sex differentiation. This study provides a theoretical basis for further analysis of the molecular mechanism of jasmonic acid regulating sex differentiation in maize.
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