梨PbrREM1.4基因在调控花粉育性中的作用机制

Fruit setting is an essential element for pear production. Most pear varieties have the phenomenon of unstable fruit setting. The main reason is that pollen can not grow healthfully in the process of pollination and reach the ovule to complete fertilization. Cell wall remodeling is the prerequisite for the healthy growth of the pollen tube. However, there has been no research on the regulation mechanism of cell wall in the process of pear reproduction. In our previous study, we have demonstrated that PbrREM1.4, a unique Remorin member in pear, expressed in pollen and regulated of callose metabolism to delay the aging process of pollen tube. It safeguard healthy growth of pollen tube in the style to complete fertilization. On this basis, we will intended to determinate of the callose metabolism genes, the interacting protein and signal transduction involved in the regulation of Remorin in pear pollen tube callose metabolism, and finally complete parsing the detailed pathway in this processes. This study will expand the understanding on the biological functions of Remorin protein in the reproductive process, and provides a new insight into understanding the molecular mechanism of pollen growth and sexual reproduction.

坐果率是决定梨树产量的重要因素之一，大多数梨品种存在坐果不稳定的现象，主要原因在于授粉过程花粉无法生长到达胚珠完成受精。细胞壁重塑是花粉管生长的前提。但是，在梨生殖过程中关于细胞壁的调控机制至今尚无明确报道。本项目前期研究发现，Group 1d是蔷薇科特有的Remorin亚家族，其中质膜定位的PbrREM1.4特异表达在梨花粉中，调控胼胝质代谢延缓花粉管衰老进程，从而维持花粉管在花柱中健康生长完成受精，但是此过程中的分子调控机制尚不清楚。本项目拟在本项目前期基础上，综合生物信息学、分子生物学和生物化学等手段，确定涉及Remorin调控的胼胝质代谢基因，明确调控途径中Remorin的互作蛋白以及信号转导过程，最终完善Remorin在花粉中调控胼胝质代谢的精细途径。这将拓展了人们对Remorin基因家族在植物生殖过程中的生物学功能的认识，为进一步理解梨花粉管生长和坐果提供新观点。

坐果率是决定梨树产量的重要因素之一，大多数梨品种存在坐果不稳定的现象，主要原因在于授粉过程花粉无法生长到达胚珠完成受精。细胞壁重塑是花粉管生长的前提。但是，在梨生殖过程中关于细胞壁的调控机制至尚无明确报道。本项目首次发现，在梨花粉管生命周期过程中，bZIP52转录因子直接结合A-box元件转录调控CalS1B.1在梨花粉管特异表达，随后CalS1B.1通过与PbrREM1.4蛋白互作固定在花粉管质膜区域行使胼胝质合成功能，以维持梨花粉管正常生长，保护梨受精过程的机理。依此,本项目提出了Remorin作为新的功能蛋白调控胼胝质代谢维持花粉管生长的新见解，为揭示梨生殖生理机制提供了重要的信息。也为克服梨园坐果不稳定的产业问题，实现梨等果树的高产品种选育等重要问题提出了方案。