A research team has unveiled 20 β-galactosidase (BGAL) genes within the longan genome, highlighting their crucial roles in embryogenic development and heat stress adaptation. Particularly, the research team spotlighted DlBGAL9, activated by transcription factors DlAGL61 and DlAGL80, as pivotal in enhancing β-galactosidase activity for cell wall thickening and stress response. These discoveries not only deepen our understanding of BGAL's function in plant development and stress mechanisms but also open pathways for agricultural innovations to improve crop resilience and productivity through genetic and biotechnological approaches.
β-Galactosidase, a crucial plant enzyme, participates in seed germination and fruit maturation by hydrolyzing complex molecules. Research has identified diverse BGAL roles across various plant species, impacting cell wall metabolism and plant development. However, specifics of its function in embryogenesis and cell wall modifications, especially in economically important crops like longan (Dimocarpus longan Lour.), remain less understood. Given longan's significance and the challenges in embryo sampling, understanding BGAL's role in cell wall metabolism during embryogenesis, and utilizing technologies like ATAC-seq for chromatin accessibility studies, emerge as a critical research area.
A study (DOI: 10.48130/frures-0024-0005) published in Fruit Research on 02 April 2024, this study elucidates the multifaceted roles of the BGAL gene family in longan development and stress adaptation, offering new insights into plant biology and potential avenues for agricultural enhancement.
A total of 20 putative BGAL genes were identified within the D. longan genome through genomic database searches and phylogenetic analysis, utilizing Arabidopsis BGAL members as references. These genes, classified into seven phylogenetic groups based on their evolutionary relationships with BGALs from other species, exhibit a range of physical properties indicative of their stability and hydrophilicity. Detailed analysis revealed the gene structure, motif composition, chromosomal distribution, and duplication events, pointing to a conservative evolution of the DlBGAL gene family, primarily driven by segmental duplications. The genes' expression patterns were examined during early somatic embryogenesis (SE) and under various stress conditions, including temperature stresses, revealing distinct roles in early SE promotion and stress response. Notably, transcription factors DlAGL61/80 were found to target DlBGAL9, enhancing its transcription and suggesting a specific regulatory network involving DlBGAL9 in response to heat stress and cell wall modification. Overexpression transgenic root studies further demonstrated the impact of DlBGAL9 and DlAGL80 on β-galactosidase activity, pectin content, and cell wall thickening, both in normal conditions and under heat stress.
According to the study's lead researcher, Prof. Yuling Lin, "Our study proposes the significance of the regulatory network composed of DlBGAL9 and TF DlAGL80 in regulating the early longan SE and heat stress response."
In summary, this research establishes a foundational model for understanding the role of BGAL genes in plant development and stress responses, highlighting the potential for genetic interventions to enhance crop resilience and productivity.
