Abstract:

The stay-green traits play an important role in delaying the aging of plants, improving effective photosynthetic efficiency and increasing crop yields; it has considerable application value in enhancing crop stress resistance and reducing fertilizer application. In order to gain a deeper understanding of the advantages and breeding potential of the stay-green trait in crops, this paper systematically reviews the current research progress on the stay-green trait from three aspects: physiological mechanism, molecular regulatory network, and breeding trend. At the physiological level, it explains that this trait stabilizes chlorophyll content, maintains photosystem activity, improves crop yields by extending the grouting period and increasing the accumulation of carbon-assimilating substances; at the level of molecular regulatory network interaction, summarized the localization and hormone signal crosstalk of key target genes (e.g., transcription factors including NAC, WRKY, and GLK), which co-regulate the senescence process and stay-green phenotype. At the breeding trend level, the stay-green trait has been widely adopted for improvements in multi-trait integration, high-efficiency nitrogen utilization, drought resistance and stress tolerance. At present, there are still some problems in the research, such as unstable QTL environment, unclear balance mechanism of stay-green and nutrient remobilization, and excessive stay-green affecting quality. In the future, we should focus on the analysis of core gene regulatory network, balance “delaying aging” and “nutritional remobilization”, and cultivate high-yield, high-quality, and suitable for mechanized production through multi-trait collaborative improvement.

Key words: stay-green trait, yield enhancement, enhanced stress resistance, breeding trends, multi-trait integration breeding