Transcriptomic Insights into the Effects of Inoculation Density in Areca catechu Tissue Culture

Tissue culture technology represents a promising strategy for addressing the supply constraints of Areca catechu seedlings. Significant differences in embryoid proliferation were observed between isolated (CK) and aggregated (GL) culture conditions during subculture. To elucidate the underlying mechanisms, transcriptomic analysis was performed. Growth analysis indicated that GL embryoids exhibited the highest growth rate (50.2%) between days 12 and 15, with a peak proliferation efficiency of 50.52%. KEGG analysis identified plant hormone signaling as a key pathway. ELISA quantification demonstrated consistently higher JA levels in CK embryos, peaking at 294.06 ng/g on day 15, while IAA levels were significantly elevated in GL embryos (46.42 ng/g on day 15). The transcription factor AcGIF1 was identified as a central regulator, with further experiments confirming that JA negatively regulates and IAA positively regulates its expression. This study provides critical insights into the molecular mechanisms governing embryoid proliferation in response to inoculation density.