Acta Agriculturae Boreali-Sinica ›› 2026, Vol. 41 ›› Issue (2): 74-82. doi: 10.7668/hbnxb.20196230

Special Issue: Biotechnology

• Crop Genetics & Breeding·Germplasm Resources·Biotechnology • Previous Articles     Next Articles

Overexpression of the OsSAUR23 Regulates the Response of Arabidopsis thaliana to ABA and GA3

GUAN Zheng1, ZHANG Yaofang2, WANG Hao1, LI Zhibin1, LUO Feng1, PEI Zhongyou1   

  1. 1 College of Agronomy and Resource Environment, Tianjin Agricultural University, Tianjin 300392, China
    2 College of Basic Sciences, Tianjin Agricultural University, Tianjin 300392, China
  • Received:2025-08-20 Published:2026-04-28

Abstract:

SAUR genes play an important regulatory role in plant growth and development.The plant hormones ABA and GA3 play key roles in the plant growth-stress response.To investigate whether the rice OsSAUR23 gene is regulated by ABA and GA3,it analyzed the cis-regulatory elements in the promoter region of the OsSAUR23 gene.Using transgenic Arabidopsis lines expressing OsSAUR23 and wild-type Arabidopsis as experimental materials,the plants were treated with exogenous hormones.By measuring agronomic traits,physiological indicators,and the expression of genes related to acid growth and the ABA pathway,the study elucidated the mechanism by which the rice OsSAUR23 gene responds to ABA and GA3.The results indicated that the promoter region of the OsSAUR23 gene contained cis-acting elements for ABA and GA3,and that the expression of the OsSAUR23 gene in rice significantly increased under ABA and GA3 treatment.Regarding agronomic traits,as ABA concentration increased,the germination rate,root length,plant height,and fresh weight of transgenic Arabidopsis were inhibited with increasing ABA concentrations,but plant height and fresh weight remained significantly higher than those of WT.GA3 treatment induced a bidirectional regulatory pattern in transgenic Arabidopsis,low concentrations promoted germination rate and root length,while high concentrations suppressed them.Plant height and fresh weight of transgenic lines were consistently higher than WT under GA3 treatment.Physiologically,SOD activity in transgenic Arabidopsis increased significantly with ABA concentration,while POD activity,CAT activity,and MDA content showed no significant difference compared to WT.Soluble protein content was significantly higher in transgenic lines.Under GA3 treatment,SOD and POD activities increased,CAT activity initially rose and then declined,MDA content first decreased and then increased,and soluble protein content remained elevated compared to WT.Furthermore,both ABA and GA3 treatments promoted a decrease in pH in the roots and other tissues of the overexpression lines,although this effect was inhibited under high hormone concentrations.qRT-PCR results demonstrated that overexpression of OsSAUR23 significantly downregulated the expression of AtPP2C.D family genes (AtAPD5,AtAPD6,and AtAPD9),which lifted the inhibition of plasma membrane H+-ATPase activity,promoted proton efflux,and ultimately led to acidification in root zones and other regions.Meanwhile,overexpression of OsSAUR23 also caused differential changes in the expression of AtPP2C.A members,suggesting its potential role in modulating ABA signaling transduction.OsSAUR23 positively regulates plant growth in response to ABA and GA3.

Key words: Rice, OsSAUR23 gene, Abscisic acid, Gibberellin, Reactive oxygen species

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Cite this article

GUAN Zheng, ZHANG Yaofang, WANG Hao, LI Zhibin, LUO Feng, PEI Zhongyou. Overexpression of the OsSAUR23 Regulates the Response of Arabidopsis thaliana to ABA and GA3[J]. Acta Agriculturae Boreali-Sinica, 2026, 41(2): 74-82. doi: 10.7668/hbnxb.20196230.

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