梨是典型的配子体型自交不亲和性果树。本项目拟在长期研究梨自交不亲和性生理及分子机制的基础上，采用全基因组测序品种‘砀山酥梨’、‘鸭梨’和‘金坠梨’（‘鸭梨’的自交亲和性突变品种）为研究材料，综合应用免疫荧光标记、分子克隆及体外表达、激光共聚焦显微镜、电镜等研究手段和技术，分析梨花柱胞外多肽StEP和HT-B在梨自交不亲和反应中的功能特性。在克隆StEP和HT-B基因的全长的基础上，通过体外表达和花柱提取纯化两种方法，获得梨花柱胞外多肽StEP和HT-B，研究其对自交不亲和花粉管生长的调控特性，探明其进入自花花粉管的运动特征并鉴定其与自花花粉管的互作蛋白，明确StEP和HT-B协同S-RNase对自交不亲和花粉管内亚细胞器结构变化特性的调控作用，最终阐明StEP和HT-B在梨自交不亲和反应中的功能机制，从而进一步完善梨自交不亲和性的分子机理。

Pear presents a typical gametophytic self-incompatibility, based on the studies on the physiological and molecular characters of the recognition between pollen and pistil in Pyrus, ‘Dangshansuli’, ‘Yali’ and ‘Jinzhuili’ (a self-compatible mutant of ‘Yali’) are selected as plant materials to investigate the mechanism of the stylar peptides StEP and HT-B in the regulation of self-pollen tube growth by various technologies including immunofluorescence label assay, molecular clone, protein expression in vitro, laser confocal scanning microscope, electron microscopy. This project covers isolation and purification of peptides StEP and HT-B from the pear styles, subcellular localizaion, and analysis of their cytological functions involved in self-incompatibility reaction including how the StEP and HT-B entering pear self-pollen tube and how many pollen proteins interacted with the stylar peptides. Finally, we will reveal the mechanism of the stylar peptides StEP and HT-B in the regulation of self-pollen tube growth in Pyrus. This is essential to improve the scientific theories of pear self-incompatibility.