Comparative Analysis of Male and Female Floral Buds

The second key stage for sexual differentiation [stage 8; initiation of microsporocytes and arrest of carpel primordia indicated by limited size increase (male floral buds); two integuments and macrosporocytes and arrest of outside stamen primordia indicated by limited size increase (female floral buds)] (Li et al., 2016 ) was observed in female and male floral buds of D. kaki in mid-April (April 15-17). The greatest divergence in MeGI expression between D. kaki female and male floral buds was also observed in mid-April (Li et al., 2019 (link)). Thus, female and male floral buds were obtained from gynoecious and androecious D. oleifera trees, respectively, at the same developmental stage from the Guangxi Zhuang Autonomous Region, China (Supplementary Figure S1) in mid-April. The samples were snap-frozen in liquid nitrogen and stored at −80°C until further analysis. Female buds were used to amplify the MeGI coding sequence and conduct the DAP-seq analysis. Female and male buds were used for determination of the salicylic acid (SA) content.