Bulletin of Botanical Research ›› 2025, Vol. 45 ›› Issue (5): 722-730.doi: 10.7525/j.issn.1673-5102.2025.05.007

• Original Paper • Previous Articles     Next Articles

Effects of Constitutive Overexpression of PagPYL4 Gene on Drought Tolerance and Growth of 84K poplar

Shang LIU, Jinhua WANG, Hasi YU, Chang LIU()   

  1. College of Forestry,State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University),Harbin 150040
  • Received:2025-04-30 Online:2025-09-20 Published:2025-09-28
  • Contact: Chang LIU E-mail:changliu0110@163.com

Abstract:

In the context of climate change intensification and increasing limitation of arable land, improving drought tolerance in forest trees has emerged as a critical breeding goal. However, achieving enhanced stress resistance without compromising growth and biomass production remains a major challenge. In this study, transgenic 84K poplar (Populus alba×P. glandulosa ‘84K’) lines constitutively overexpressing PagPYL4 gene, an abscisic acid(ABA) receptor gene, were developed, and their physiological and growth responses were evaluated under drought stress. The results showed that under the influence of exogenous ABA, the overexpression of PagPYL4 gene significantly altered stomatal aperture in plants. Under short-term drought treatment, compared with the wild type, the overexpression of PagPYL4 gene reduced water loss and improved drought tolerance; however, it also inhibited stomatal conductance and photosynthetic rate, leading to a significant decrease in growth rate of plant height and ground diameter. Our findings demonstrated that while PagPYL4 overexpression effectively enhanced drought resistance, its indiscriminate activation can impose substantial growth penalties. This highlighted the importance of spatially and temporally regulated gene expression strategies to balance stress resilience and biomass productivity in future tree breeding programs.

Key words: Populus alba×P. glandulosa ‘84K’, PagPYL4, drought tolerance, growth, stomata, photosynthesis

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