ABA-GA Antagonism and Modular Gene Networks Cooperatively Drive Acquisition of Desiccation Tolerance in Perilla Seeds

Xiaohuan Yang¹Minghao Chen¹Mingwang Liu^2,3Bowen Li¹Zhichao Sun¹Ailian Lu¹Sen Zhang¹Xinghai Shi¹Jun Ren¹Xiuzhen Qin¹Jinhu Ma^4*

• ¹College of Agricultre, Shanxi Agricultural University, Taigu, China
• ²Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
• ³University of Chinese Academy of Sciences, Beijing, China
• ⁴School of Innovation and Intrepreneurship,, Shanxi Agricultural University, Taigu, China

Seed desiccation tolerance (DT) is gradually acquired during development, but the genetic mechanisms underlying the acquisition of DT in perilla seeds remain unclear.Our study revealed that the D17-D27 period is a critical dehydration window. During this phase, seed vigor increases alongside embryo development, seed coat thickening, and endosperm degradation, while reduced moisture content triggers the initiation of the DT mechanism. In physiological regulation, enhanced antioxidant enzyme activity and the dynamic balance of MDA maintain oxidative homeostasis, while sucrose accumulation and ABA-GA antagonism collaboratively regulate the dehydration response.Transcriptome analysis identified 14,040 DEGs expressed at different developmental stages. Combining these results with physiological traits, we performed WGCNA analysis and identified the MEcoral module, which maintains membrane integrity through lipid metabolism, endoplasmic reticulum protein processing, and ABA signaling, while the MElavenderblush2 module regulates energy supply and cell wall remodeling through photosynthetic carbon metabolism and GA signaling. The core gene network (ABI5/BBX22/MADS3) shows that the BBX family may integrate ABA, heat stress, and light signaling pathways, coordinating antioxidant defense and energy metabolism to enhance the seed's overall adaptability. This study elucidates the mechanism of DT acquisition in perilla seeds and provides a theoretical basis for the genetic improvement of crop stress resistance.