Tuber dormancy is a vital process that delays sprouting after harvest, preserving seed vigor and quality. However, the unpredictable timing of sprouting presents ongoing challenges for the potato industry. While previous research has identified key genes influencing dormancy, the detailed molecular mechanisms remained unclear. To address these challenges, further exploration into the hormonal and genetic control of dormancy became a research priority for enhancing potato breeding and storage efficiency.
The research team at Sichuan Agricultural University published their findings on 8 November 2023 in Horticulture Research. Their study (DOI: 10.1093/hr/uhad228) investigates the interaction between two proteins, StSN2 and StBIN2, and reveals how their combined activity regulates potato dormancy by influencing abscisic acid (ABA) and brassinosteroid (BR) signaling. These insights provide new avenues for better managing post-harvest storage by targeting molecular processes.
The study demonstrated that StSN2 interacts directly with StBIN2, a key suppressor in BR signaling, to extend tuber dormancy. The researchers used yeast two-hybrid, luciferase complementation, and Co-IP assays to verify this interaction. The results showed that StSN2 boosts StBIN2's expression and enzyme activity, which in turn enhances ABA signaling by upregulating SnRK2.2/2.3/2.6 and ABI5, while simultaneously suppressing BR signaling by inhibiting StBZR1. Mutagenesis experiments pinpointed crucial cysteine residues in StBIN2 that facilitate its interaction with StSN2, directly linking this mechanism to dormancy control. Overexpressing both proteins led to significantly longer dormancy periods, confirming their role in delaying sprout development.
“This study underscores the essential function of StSN2 and StBIN2 in regulating hormonal pathways that influence dormancy,” said Dr. Xiyao Wang, the lead researcher. “Our deeper understanding of these molecular processes presents new opportunities for improving potato storage through genetic manipulation.”
The study’s findings offer practical benefits for agriculture, particularly in improving post-harvest storage for potatoes. By controlling the StSN2-StBIN2 interaction, it may be possible to extend the tuber dormancy period, reducing losses from premature sprouting. This discovery also holds promise for future breeding programs focused on improving storage durability and reducing dependence on chemical sprout inhibitors.Newswise/SP