Genome-wide identification and functional analysis of the bZIP gene family in Mikania micrantha
Yongmei Zhu1,2, Yanxin Yan1,2, Yan'e Ding1,2
1Forest Resources Exploitation and Utilization Engineering Research Center for Grand Health of Yunnan Provincial Universities, Southwest Forestry University, Kunming, China.
Background:
Mikania micrantha is a globally notorious invasive weed, whose invasion success is driven by rapid biomass accumulation and robust environmental adaptability. Unraveling the molecular switches governing its growth is therefore essential for developing precise management strategies. bZIP transcription factors serve as pivotal regulators in plant stress responses and development. In this study, using Alternaria gossypina infection as a biotic stress stimulus, we conducted a genome-wide identification of the MmbZIP gene family and functionally characterized the core molecular modules regulating its invasive adaptability.
Results:
Genome-wide analysis identified 99 MmbZIP genes classified into 11 subfamilies. Transcriptomic profiling highlighted the stress-responsive Group A, identifying MmbZIP32 as a core member significantly and continuously upregulated upon A. gossypina infection. Crucially, MmbZIP32 expression exhibited a synchronized, strong positive correlation with pheophorbide a oxygenase (PAO), the rate-limiting gene in chlorophyll degradation. Mechanistically, subcellular localization confirmed the nuclear presence of MmbZIP32, and yeast one-hybrid assays demonstrated its direct binding to specific cis-acting elements within the PAO promoter, confirming a transcriptional regulatory relationship.
Conclusion:
This study provides a comprehensive genome-wide identification of the bZIP transcription factor family in M. micrantha and sheds light on their potential roles in biotic stress response. Our findings suggest that the Group A member MmbZIP32 may function as a candidate regulator potentially linked to the chlorophyll degradation pathway (e.g., PAO) to modulate stress adaptability. This work contributes to the theoretical understanding of the molecular networks governing the growth of M. micrantha and highlights promising candidates for future research into invasive mechanisms and weed management strategies. © 2026 Society of Chemical Industry.
