Expression change during the leaf sink-to-source transition of soybean
Immature soybean leaves initially act as sinks that import photosynthate from mature source leaves and gradually acquire source capacity through the leaf sink–to–source transition. To investigate the molecular basis of this shift, we combined ¹4C tracer analysis with RNA-seq. During second trifoliate leaves (L2) development, mature leaves were supplied with ¹4CO2, and L2 were collected and classified as sink, transition, or source states based on their ¹4C allocation patterns. Because ¹4C distribution patterns also indicated regulatory activity in the stem, node tissues were included for RNA-seq profiling. Transcriptome analyses revealed rapid and coordinated changes in pathways related to carbohydrate and lipid metabolism, hormonal signaling, and defense responses. These results provide new insight into the molecular regulation of the sink–to–source transition in soybean.
Immature soybean leaves initially act as sinks that import photosynthate from mature source leaves and gradually acquire source capacity through the leaf sink–to–source transition. To investigate the molecular basis of this shift, we combined ¹4C tracer analysis with RNA-seq. During second trifoliate leaves (L2) development, mature leaves were supplied with ¹4CO2, and L2 were collected and classified as sink, transition, or source states based on their ¹4C allocation patterns. Because ¹4C distribution patterns also indicated regulatory activity in the stem, node tissues were included for RNA-seq profiling. Transcriptome analyses revealed rapid and coordinated changes in pathways related to carbohydrate and lipid metabolism, hormonal signaling, and defense responses. These results provide new insight into the molecular regulation of the sink–to–source transition in soybean.