Sex Expression in Chinese Persimmons

Abstract

AbstractSexual types of Diospyros spp. are diverse. Here, monoecious, androgynomonoecious, androecious, and andromonoecious Diospyros spp. trees, which can bear male flowers, are collectively defined as male D. spp. germplasm resources (MDGR). In this chapter, the descriptors and data standards for the evaluation of MDGRs were firstly improved. Then 14 representative MDGRs were introduced in detail with both texts and pictures. Finally, the differentiation mechanism of hermaphroditic floral buds of a special andromonoecious D. kaki tree was highlighted. The third part uncovered that early (Stage 2) and mid-April (Stage 4) were critical morphological periods for sex differentiation of hermaphroditic floral buds compared with male floral buds. At both stages, OGI was differentially expressed in male and hermaphroditic buds, but MeGI was not. This was different from their expressions in dioecious and monoecious persimmons. High jasmonic acid (JA) levels at stage 4 and high zeatin (ZT) levels at stages 2 and 4 might have promoted hermaphroditic floral bud differentiation. In phytohormone biosynthesis and signaling pathways, 52 and 54 differential expression genes (including Aux/IAA, ARFs, DELLA, AHP, A-ARR, B-ARR, CYP735A, CRE1, PP2C, JAZ, MYC2, COI1, CTR1, SIMKK, ACO, and MPK6) were identified, respectively. During the development of male floral buds, five metacaspases genes might have been involved in pistil abortion. Noteworthy, miR169v_1, miR169e_3, miR319_1, and miR319 were predicted to contribute to phytohormone biosynthesis and signaling pathways and floral organogenesis and might also regulate hermaphroditic floral bud sex differentiation.