Bud dormancy is an important survival strategy for fruit trees in temperate climates, as it helps them withstand adverse environmental conditions. However, in evergreen perennials such as lychees, dormancy can occur even in ideal conditions, which presents special challenges.

To address these challenges, further research into the molecular mechanisms controlling dormancy in evergreen species such as litchi is needed to improve agricultural practices and crop management.

Researchers from South China Agricultural University published their findings in the May 28, 2024 issue of Horticultural research.

The study focuses on the MIKC-type MADS-box transcription factor LcSVP2, a gene critical for regulating dormancy in the terminal buds of lychee. The research also investigates the role of LcSVP2 as a flowering repressor, providing new insights into its dual function and its potential impact on cultivation practices of lychee and other fruit crops.

The study identifies LcSVP2 as a central regulator of dormancy in litchi terminal buds, with high expression levels observed during growth arrest and dormancy phases. Using a virus-induced gene silencing (VIGS) assay, the researchers showed that silencing of LcSVP2 significantly delays re-entry into dormancy, highlighting its essential role in this process.

In addition, LcSVP2 acts as a floral repressor because its overexpression in Arabidopsis delays flowering. The research also found that LcSVP2 interacts with another transcription factor, LcSMOS1, to co-regulate bud dormancy.

Both LcSVP2 and LcSMOS1 were found to respond to dormancy hormones such as abscisic acid (ABA) and ethylene, highlighting their role in dormancy regulation and providing new approaches for crop management strategies.

Dr. Ren-Fang Zeng, one of the lead authors of the study, emphasized the importance of this discovery. “Understanding the dual role of LcSVP2 in dormancy and flowering opens new perspectives on the interconnected processes in lychee. This knowledge is essential for the development of improved cultivation methods, especially in regions where lychee is a major agricultural product,” noted Dr. Zeng, underscoring the far-reaching implications of the study.

The findings from this study are likely to have significant implications for gardeners and agronomists working with evergreen species.

By elucidating how LcSVP2 regulates dormancy and flowering, new strategies can be developed to better control these processes in lychee, potentially leading to improved yields and fruit quality.

Furthermore, this research paves the way for studying similar genetic mechanisms in other evergreen perennials, which could have significant implications for the cultivation of tropical and subtropical crops and contribute to more sustainable agricultural practices.