科学家破解大麦种子休眠关键机制 助力应对气候与粮食挑战

Core Insights - The research team from the Chinese Academy of Sciences has identified the key mechanism behind barley seed dormancy, which could lead to sustainable high-performance agricultural systems through genomic design breeding, addressing food security challenges posed by extreme climate change and population growth [1][2]. Group 1: Seed Dormancy Mechanism - Seed dormancy allows seeds to remain inactive under suitable germination conditions until the environment is safe for germination, a critical trait modified during crop domestication [1]. - The MKK3 gene plays a crucial role in controlling the dormancy rhythm of barley across different climate zones through its copy number and amino acid variations affecting kinase activity [1][2]. - The research analyzed over 1,000 barley seed samples to understand the spatiotemporal evolution of MKK3, revealing that climate and agricultural demands influence the selection of MKK3 types by humans [1]. Group 2: Adaptation in High-Altitude Regions - Qingke barley has the highest MKK3 activity globally, exhibiting the weakest dormancy and strongest germination ability, which is crucial for adapting to the extreme climate of the Tibetan Plateau [2]. - Local agricultural practices involve harvesting barley before full maturity to mitigate low-temperature issues during the harvest season, followed by post-harvest treatments to facilitate winter storage and consumption [2]. - The dual regulatory mechanism of MKK3 provides actionable molecular modules for breeding resilient crops, supporting sustainable agricultural development under current global climate change conditions [2]. Group 3: Regional Variations in Dormancy - Short dormancy periods can lead to premature germination during continuous rainy weather, reducing yield and quality, while excessively long dormancy can affect replanting timing and seedling uniformity [3]. - The East Asian monsoon region favors a "low activity mode" of MKK3 for longer dormancy to avoid germination issues caused by humid and hot conditions during harvest [3]. - In contrast, the Tibetan Plateau's naked barley (Qingke) has adopted the "highest activity mode" globally to ensure rapid activation of seeds after early harvesting [3].