AGPs蛋白在植物中普遍存在且在有性生殖过程中扮演重要角色。本研究对梨花粉管中表达的PbrAGPs基因进行全面鉴定并探究其对花粉管生长的影响。共鉴定到187个基因在梨花粉中表达，通过转录组分析发现38个PbrAGPs在花粉中特异性表达。花粉中表达的PbrAGPs基因被划分为特异性表达和高表达两组。采用组织定位和荧光定量分析两组基因的表达模式发现，多数的PbrAGPs非特异性的在花粉中表达，并且这些基因的表达模式与RPKM值的表达趋势一致，这也表明PbrAGPs参与花粉管的生长发育过程。此外，构建系统发育树来全面鉴定参与调控梨花粉管生长的PbrAGPs基因。因此，共选取了19个PbrAGPs (PbrAGP1~PbrAGP19)来验证其对花粉管生长的影响。原核表达纯化19个PbrAGP-his重组蛋白，用其体外处理梨花粉，发现共11个PbrAGP-his重组蛋白可显著促进梨花粉管生长。此外，通过反义寡核苷酸技术抑制花粉管中PbrAGP的表达，发现抑制PbrAGP1和PbrAGP5的表达水平后，可以显著抑制梨花粉管的生长。PbrAGP1和PbrAGP5定位于质膜，并且对花粉管细胞壁果胶的分布基本没有影响。综上所述，本研究主要鉴定了梨花粉中表达的PbrAGPs基因，为探索其在花粉管生长中的作用奠定了基础。

The free putrescine (Put) content, the hydrogen peroxide (H2O2) content and the polyamine oxidase (PAO) activity in roots of Malus hupehensis Rehd. var. pinyiensis Jiang (PYTC) were significantly increased, and reached its peak at 1, 2 and 6 h, respectively, under cadmium treatment. The free spermine (Spm) and spermidine (Spd) contents were dramatically decreased, and reached the minimum value at 4-6 h, then remained relatively stable. The change in total free polyamines (PAs) content was consistent with that of free Put. The number of root dead cells was gradually increased after treatment for 24 h, and the typical characteristics of programmed cell death (PCD) were displayed at 48 h. Throughout the Cd treatment process, changes in PAs metabolism appeared to be prior to cell death increase, and the H2O2 content was always maintained at a high level. These results indicated that polyamines could initiate cell death by generating H2O2 in roots of Malus hupehensis Rehd. under CdSO4 stress.