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Scientia Silvae Sinicae ›› 2026, Vol. 62 ›› Issue (2): 126-133.doi: 10.11707/j.1001-7488.LYKX20250329

• Research papers • Previous Articles    

PagABP1 in Populus Mediates Auxin Signaling to Influence Plant Growth

Shen Wang1,2,Zhixin Zeng1,2,Jing Qiao1,2,Yuxin Wang1,Ruiqi Zheng1,2,Qi Wang1,2,Hui Wu1,2,Qiqi Zhang1,Yang Jiao1,2,Wenbo Shu1,2,*()   

  1. 1. National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops Huazhong Agricultural University Wuhan 430070
    2. Shennongjia Science and Technology Innovation Center, Huazhong Agricultural University Shennongjia 442422
  • Received:2025-05-21 Revised:2025-08-25 Online:2026-02-25 Published:2026-03-04
  • Contact: Wenbo Shu E-mail:wenboshu@mail.hzau.edu.cn

Abstract:

Objective: Through genome-wide identification and bioinformatics analysis of PagABP gene family of Populus alba × P. glandulosa, the gene PagABP1 that is highly expressed in young stems, cambium, xylem and phloem was selected to explore its effect on radial and height growth of this poplar. This study aims to provide a theoretical basis for elucidating how the auxin signaling pathway regulates secondary growth of stems by studying the regulatory role of this gene in the radial and height growth of poplars. Method: Bioinformatics and related software were used to identify the members of the PagABP gene family in 84K poplar. The real-time fluorescence quantitative PCR was used to analyze the expression of PagABP1 gene in terminal buds, young leaves, young stems, young roots, mature stems, old roots, root tips, phloem, vascular cambium and xylem. Plant PPagABP1::GUS promoter vector and overexpressing 35S::PagABP1 vector were constructed by using the PagABP1 promoter and coding region sequences, respectively. Agrobacterium-mediated method was used to create 84K poplar transgenic materials that were used to identify the effects of PagABP1 gene on poplar radial and height growth. Result: Two ABP homologous genes were identified in 84K poplar genome, and the PagABP1 gene showed relatively higher expression levels in the apical bud, young stems, phloem, cambium, and xylem. The expression locations of PPagABP1::GUS in transgenic poplar were overlapped with those of PpagDR5::GUS (auxin response reporter gene), mainly in the terminal bud, young stem, cambium, phloem, and primary xylem, suggesting that PagABP1 is involved in auxin-mediated regulation of radial and height growth. The germination number and growth rate of PagABP1-OE lines were significantly higher than those of the control when the truncated seedlings were planted in soil. Analysis of transgenic lines (#17、#26) that overexpressed PagABP1 gene at 60 days showed that the width of the cambium, primary xylem, and phloem of 12th internode, plant height and basal diameter increased by 50.2%, 43.3%, 1.58%, 19.14% and 19.29%, respectively, compared to the control. Conclusion: PagABP1 gene is associated with auxin expression site, mainly expressed in terminal buds, young stem, phloem, cambium, and primary xylem, affecting radial and height growth. This study can lay a foundation for further revealing the molecular mechanism of PagABP1 gene involved in stem growth of 84K poplar.

Key words: Populus alba × P. glandulosa, auxin signaling, PagABP1, radial growth, height growth

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