Mechanisms Of Sex Conversion Induced By CPPU In Male Viits Amurensis Rupr

CPPU could induce sex conversion in male Vitis amurensis Rupr. Researches from femalegametophyte, fruit characters, endogenous hormones, pollen vigor and differential proteomics on bothcontrol and CPPU treated male V. amurensis flower buds at different developmental stages weresystemly reported in this paper.1.The male V. amurensis cultivars treated with100mg·L-1CPPU about15days before anthesisshow the satisfactory fruit characters. Relationship between pollen germinationin of male V. amurensisand CPPU was observed and we found that pollen germinationin rate was reduced by CPPU.2.It was observed that CPPU induced the ovul development of male V. amurensis flower buds.There was no significant difference between control and treatment male V. amurensis flower buds onfemale gametophyte morphology before the formation of the megaspore mother cell. Single-nucleusembryo sac formed in control flower buds, while two-nuclei embryo sac formed in treated flower budsat8th day after treatment. In the later development stages, female gametes in embryo sac of treated maleV. amurensis flower buds divided normally and eight-nuclei embryo sac formed ultimately. However,female gametes in embryo sac of control male V. amurensis flower buds divided abnormally, embryo sacfailed to thrive and disintegrated gradually after the formation of three-nuclei embryo sac.3.Endogenous hormones play a key role in sex conversion of male V. amurensis. The changementof four endogenous hormones （abscisic acid （ABA）, gibberellic acid （GA₃）, indole-3-acetic acid （IAA）,zeatin riboside （ZR）） change) content happened before morphology. The contents and the ratios ofendogenous hormones of treatment flower buds performed differently compare to that in control flowerbuds at different stages of sex conversion. These results suggested that quantitative changes and thebalance between endogenous hormones at different stages were involved in the sex conversion of maleV.amurensis.4.Two-dimensional gel electrophoresis （2-DE） was performed to establish an effective2-DEplatform using male V. amurensis flower tissue. The results showed that2-DE gels with aboundant spots,high repeatability and resolution could obtained if proteins extracted by phenol extraction method,dissolved by lysis bufferⅡand separated by17cm immobilized pH gradient strips with pH4-7.5.The key protein related to sex conversion of male V. amurensis, APT3, was identified on the baseof differential protemics. Furthermore, all of the proteins involved in ubiquitin/proteasome pathway，cellstructure, membrane fusion and vesicular trafficking, ROS-scavenging mechanism, energy metabolismand secondary metabolism directly or indirectly participated in flower development.