Programmed Cell Death Facilitates the Formation of Unisexual Male and Female Flowers in Persimmon (<i>Diospyros kaki</i> Thunb.)
Liyuan Wang,
Huawei Li,
Yujing Suo,
Weijuan Han,
Songfeng Diao,
Yini Mai,
Peng Sun,
Fangdong Li,
and Jianmin Fu
Affiliations
Liyuan Wang
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Huawei Li
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Yujing Suo
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Weijuan Han
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Songfeng Diao
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Yini Mai
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Peng Sun
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Fangdong Li
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
and Jianmin Fu
Key Laboratory of Non-timber Forest Germplasm Enhancement & Utilization of State Administration of Forestry and Grassland; Non-timber Forest Research and Development Center, Chinese Academy of Forestry; National Innovation Alliance of Persimmon Industry, No. 3 Weiwu Road, Jinshui District, Zhengzhou 450003, China
Most varieties of persimmon (Diospyros kaki Thunb.) are gynoecious, while just a few are either monoecious, androgynomonoecious, or androecious. Persimmon flowers initially contain the original androecium and gynoecium followed by arrest of either pistil or stamen primordia before maturity. Abortion of inappropriate primordium in persimmon may be related to programmed cell death (PCD). To test this hypothesis, hematoxylin and eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, cyt-c immunohistochemistry (IHC) assay, transmission electron microscopy (TEM) observation, and real-time quantitative polymerase chain reaction (RT-qPCR) were used to clarify the occurrence and molecular regulatory mechanism of PCD in male and female floral buds during the 14 days prior to the second crucial morphological stage when inappropriate sexual primordia were arrested to form unisexual flowers. Accordingly, dead cells in inappropriate sex organs were largely accumulated during the microsporocyte and macrosporocyte period of male and female floral buds, respectively. This may explain the abortion of inappropriate sex organs, leading to unisexual flowers. PCD is necessary for normal growth and development in persimmons, as dead cells could also be observed in the normal flower organs. High levels of a gene homologous to AMC9 may have accelerated the arrest of the pistil primordium during differentiation, leading to male unisexual flowers, and high levels of genes homologous to MeGI, BAG5, AifA, and HSP70 in female floral buds were positively correlated with the arrest of stamen primordium. Future studies may try to transform unisexual flowers into hermaphroditic flowers by the regulation of PCD artificially, which will be helpful to the controlled pollination experiments.
