Sweet switch: Sorbitol's key role in apple plant growth strategy
image: Proposed models illustrating how sorbitol mediates age-dependent changes in apple plant growth strategy through gibberellin signaling.
Credit: Horticulture Research
A recent study reveals the critical role of sorbitol in driving age-dependent growth shifts in apple plants. Researchers have uncovered how sorbitol interacts with gibberellin signaling to transition growth from a rapid juvenile phase to a slower adult pattern. This discovery provides essential insights into the mechanisms controlling plant maturation and development.
Apple trees, like many perennial plants, endure a prolonged juvenile stage before reaching maturity, during which they experience complex developmental changes. These transitions impact photosynthetic traits, growth rates, and hormone balance. However, the mechanisms governing these processes are not well understood, complicating efforts to enhance fruit tree productivity. Given the economic importance of apple cultivation, researchers strive to unravel these developmental cues. Addressing these complexities necessitates exploring genetic and physiological interactions that dictate growth strategies, paving the way for advances in agricultural practices and improved crop performance.
A study (DOI: 10.1093/hr/uhae192) from the State Key Laboratory for Crop Stress Resistance at Northwest A&F University, published on July 11, 2024, in Horticulture Research, investigates sorbitol's impact on growth transitions in apple plants. The findings show that sorbitol accumulation drives the shift from fast to slow growth as apple plants age. These insights highlight crucial genetic mechanisms regulating developmental transitions, setting the stage for future agricultural advancements.
The study details how apple plants undergo significant age-dependent changes, including shifts in photosynthetic efficiency, hormone regulation, and carbon metabolism. Researchers utilized tissue-cultured apple plants to represent juvenile, transition, and adult stages, measuring variations in plant height, photosynthetic rates, and hormone levels. A key finding was the identification of MdSDH1, a gene crucial for sorbitol breakdown, highly active during the juvenile phase. Suppressing MdSDH1 led to decreased gibberellin (GA3) levels and plant growth, but exogenous GA3 restored these traits, underscoring the gene’s role in growth regulation. The study also revealed that accumulated sorbitol activates the MdSPL1-MdWRKY24 module, which suppresses growth-related genes and enforces a slow-growth strategy. By linking metabolic and genetic signals, the research emphasizes sorbitol’s dual function as a carbon source and a signaling molecule, enriching our understanding of apple tree development.
Dr. Fengwang Ma, the lead author, emphasized the study's significance: “Our research uncovers how sorbitol and genetic regulators work together to govern apple plant growth. By understanding these intricate mechanisms, we can better manage growth phases and boost agricultural productivity. This study not only deepens our understanding of perennial plant development but also sets the foundation for advanced breeding and management strategies to optimize fruit tree performance.” The findings represent a notable advancement in plant science, with the potential to revolutionize apple cultivation practices.
The research has far-reaching implications for the apple industry, offering methods to fine-tune tree growth and fruit yield by managing hormonal and metabolic pathways. By adjusting sorbitol levels and the associated genetic factors, breeders can develop apple varieties with enhanced growth traits and better environmental resilience. Furthermore, the study sheds light on regulating carbon and hormone dynamics to control maturation speed, catering to diverse agricultural needs. This work provides a strategic foundation for improving fruit production and sustainability, addressing challenges posed by climate change and resource constraints.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhae192
Funding information
This work was supported by the National Key Research and Development Program of China (2023YFD2301000), the Earmarked Fund for the China Agriculture Research System (CARS-27), the Key S&T Special Projects of Shaanxi Province (2020zdzx03-01-02), and the Chinese Universities Scientific Fund (2452023067).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2022. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.