Open Access

ARTICLE

Expression Analysis and Functional Validation of Lily LoWRKY22

Ling He, Shun Tao, Qian Wang, Yu-Pei Yin, Xin-Yu He, Shuo Shi, Chun-Yan Wang^*

College of Horticulture and Landscape Architecture, Jinling Institute of Technology, Nanjing, China

* Corresponding Author: Chun-Yan Wang. Email:

(This article belongs to the Special Issue: Advances in Ornamental Plants: Micropropagation, Plant Biotechnology, Chromosome Doubling, Mutagenesis, Plant Breeding, Environmental Stress Tolerance, and Postharvest Physiology)

Phyton-International Journal of Experimental Botany 2026, 95(6), 17 https://doi.org/10.32604/phyton.2026.081349

Received 28 February 2026; Accepted 24 April 2026; Issue published 29 June 2026

Abstract

As essential regulatory proteins, WRKY transcription factors participate in the regulation of plant growth, development and stress resistance; however, the functions of LoWRKY22 in the ‘Siberia’ cultivar of Lilium remain uncharacterized. In this study, LoWRKY22 was cloned and subjected to comprehensive functional analyses. Phylogenetic analysis revealed that LoWRKY22 belongs to the WRKY-IIe type subgroup, featuring a conserved WRKY domain and a C2H2-type zinc finger motif, indicating evolutionary conservation with WRKY homologs from Arabidopsis thaliana. Subcellular localization and transactivation assays confirmed its nuclear localization and transcriptional activation activity, supporting its role as a transcriptional regulator. Structural characterization of the LoWRKY22 promoter identified multiple cis-elements responsive to light, low temperature, and gibberellin, suggesting its involvement in environmental and hormonal signaling pathways. Tissue expression analysis demonstrated predominant expression of LoWRKY22 in leaves, consistent with its proposed roles in photosynthesis- and senescence-related processes. The heterologous overexpression of LoWRKY22 in Arabidopsis thaliana induced early flowering, reduced plant height, and accelerated silique maturation relative to those in wild-type plants. Quantitative real-time polymerase chain reaction (PCR) revealed that LoWRKY22 overexpression significantly upregulated senescence-associated genes (AtWRKY53, AtSAG12, and AtSAG13) and flowering-promoting genes (AtFT and AtAP1), while downregulating the floral repressor AtFLC. These findings indicate that LoWRKY22 functions as a positive regulator of flowering and senescence, potentially coordinating the transition from vegetative to reproductive growth via the modulation of key regulatory networks. Collectively, this research firstly identified and explored the functions of LoWRKY22 in the‘Siberia’ cultivar of Lilium, elucidating its regulatory role in growth-phase transitions and establishing a molecular foundation for its potential utilization as a candidate gene in genetic breeding programs aimed at optimizing growth, flowering time, and developmental traits in lilies.

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Keywords

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