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Journal of Integrative Agriculture  2023, Vol. 22 Issue (3): 776-789    DOI: 10.1016/j.jia.2023.02.007
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Identification and functional analysis of arabinogalactan protein expressed in pear pollen tubes
JIAO Hui-jun, WANG Hong-wei, RAN Kun, DONG Xiao-chang, DONG Ran, WEI Shu-wei#, WANG Shao-min#

Shandong Institute of Pomology, Tai’an 271000, P.R.China

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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花粉管中表达的PbrAGPs基因进行全面鉴定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38PbrAGPs在花粉中特异性表达花粉中表达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,构建系统发育树全面鉴定参与调控梨花粉管生长的PbrAGPs基因。因此,选取了19PbrAGPs (PbrAGP1~PbrAGP19)来验证其对花粉管生长的影响。原核表达纯化19PbrAGP-his重组蛋白,用其体外处理梨花粉,发现共11PbrAGP-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PbrAGP1PbrAGP5的表达水平后,可以显著抑制梨花粉管的生长。PbrAGP1PbrAGP5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。


Arabinogalactan proteins (AGPs) are widely distributed in the plant kingdom and play a vital role during the process of plant sexual reproduction.  In this study, we performed a comprehensive identification of the PbrAGPs expressed in pear pollen and further explored their influences on pollen tube growth.  Among the 187 PbrAGPs that were found to be expressed in pear pollen tubes, 38 PbrAGPs were specifically expressed in pollen according to the RNA-seq data.  The PbrAGPs were divided into two groups of highly expressed and specifically expressed in pear pollen.  We further tested their expression patterns using RT-PCR and RT-qPCR.  Most of the PbrAGPs were expressed in multiple tissues and their expression levels were consistent with reads per kilobase per million map reads (RPKM) values during pollen tube growth, implying that PbrAGPs might be involved in the regulation of pear pollen tube growth.  We also constructed phylogenetic trees to identify the functional genes in pear pollen tube growth.  Therefore, 19 PbrAGPs (PbrAGP1 to PbrAGP19) were selected to test their influences on pollen tube growth.  Recombinant proteins of the 19 PbrAGP-His were purified and used to treat pear pollen, and 11 of the PbrAGP-His recombinant proteins could promote pear pollen tube growth.  Additionally, pollen tube growth was inhibited when the expression levels of PbrAGP1 and PbrAGP5 were knocked down using an antisense oligonucleotide assay.  PbrAGP1 and PbrAGP5 were localized in the plasma membrane and might not alter the distribution of pectin in the pollen tube.  In summary, this study identified the PbrAGPs expressed in pear pollen and lays the foundation for further exploring their functions in pollen tube growth.

Keywords:  arabinogalactan proteins       pear        pollen tube        antisense oligodeoxynucleotides        sexual reproduction  
Received: 24 March 2022   Accepted: 19 December 2022

This research was supported by the earmarked fund for China Agriculture Research System (CARS-28-37), the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences, China (CXGC2022E21), the Youth Foundation of Shandong Institute of Pomology, China (GSS2022QN11) and the Natural Science Foundation of Shandong Province, China (ZR2019BC075, ZR2020MC141, and ZR2021MC177).

About author:  JIAO Hui-jun, E-mail:; #Correspondence WEI Shu-wei, Tel: +86-538-8207123, E-mail:; WANG Shao-min, E-mail:

Cite this article: 

JIAO Hui-jun, WANG Hong-wei, RAN Kun, DONG Xiao-chang, DONG Ran, WEI Shu-wei, WANG Shao-min. 2023. Identification and functional analysis of arabinogalactan protein expressed in pear pollen tubes. Journal of Integrative Agriculture, 22(3): 776-789.

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