Chinese cabbage, a fast-growing, economically important leafy vegetable, has its flowering timing closely tied to environmental cues, particularly vernalization. The regulation of flowering in this crop is a complex process that depends on the activity of the shoot apex and prolonged cold exposure, both critical for optimal yield. While the molecular and cellular mechanisms driving this process have been extensively studied in model plants like Arabidopsis, the detailed regulatory networks in Chinese cabbage have remained largely unexplored. Given this gap in knowledge, understanding how the shoot apex functions in flowering regulation is essential for improving breeding practices and crop management.
On July 30, 2024, a team of researchers from the State Key Laboratory of Vegetable Biobreeding at the Chinese Academy of Agricultural Sciences unveiled their findings (DOI: 10.1093/hr/uhae214) in Horticulture Research. By leveraging single-cell RNA sequencing, they constructed a detailed transcriptomic atlas of the Chinese cabbage shoot apex, offering new insights into the cellular mechanisms that regulate flowering and vernalization in this important vegetable.
The study provides an in-depth look at the cellular and molecular underpinnings of flowering and vernalization in Chinese cabbage. Researchers analyzed 19,602 single cells from the shoot apex of 25-day-old, non-vernalized Chinese cabbage, identifying 15 distinct cell clusters using well-established marker genes. They found that key genes involved in shoot apex development and flowering were primarily expressed in shoot meristematic cells (SMCs), companion cells (CCs), and mesophyll cells (MCs). Notably, the MADS-box protein FLOWERING LOCUS C 2 (BrFLC2), a gene that suppresses flowering, was predominantly expressed in CCs, mirroring patterns seen in Arabidopsis. Through mapping the developmental trajectories of these cell types, the researchers traced the evolutionary pathways of crucial genes in shoot apex development and flowering. The study also revealed how vernalization altered the expression of important flowering genes, including VERNALIZATION INSENSITIVE 3 (VIN3), VERNALIZATION 1 (VRN1), VERNALIZATION 2 (VRN2), FLOWERING LOCUS T (FT), and BrFLC. These findings underscore the transformative potential of single-cell RNA sequencing in decoding the complex processes of differentiation and vernalization in Chinese cabbage, advancing both our understanding of its developmental biology and strategies for crop improvement.
Dr. Shujiang Zhang, one of the lead researchers, emphasized the broader significance of the study: "Our research not only provides a detailed cellular map of the Chinese cabbage shoot apex but also highlights conserved and unique aspects of flowering regulation. This breakthrough opens up new possibilities for enhancing breeding strategies and improving crop management."
The implications of this research are far-reaching, particularly in the field of agricultural biotechnology. By revealing the specific gene expression patterns and cellular interactions involved in flowering, this study offers breeders the tools to develop Chinese cabbage varieties with optimized flowering times and enhanced adaptability to varying environmental conditions. The findings pave the way for more efficient and sustainable cultivation practices, benefiting both farmers and consumers alike.
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References
DOI
10.1093/hr/uhae214
Original Source URL
https://doi.org/10.1093/hr/uhae214
Funding information
This research was supported by the National Key Research and Development Program of China (2023YFD1201504), the China Agriculture Research System (CARS-23-A-14), the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-IVFCAAS), and the National Natural Science Foundation of China (32102373 and 32172562).
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.