Recently, the research group of Professor Kang Xiangyang from the College of Biological Science and Technology made new progress in gene expression and regulation of poplar leaf development, and the research result entitled "Spatiotemporal miRNA and transcriptomic network dynamically regulate the developmental and senescence processes of poplar leaves" in Horticulture Research (IF=8.7) .

Poplar is an important afforestation and urban greening species. Poplar leaf development occurs in stages, from young to mature and then from mature to senescent; these are accompanied by various phenotypic and physiological changes. However, the associated transcriptional regulatory network is relatively unexplored. We first used principal component analysis to classify poplar leaves at different leaf positions into two stages: developmental maturity (the stage of maximum photosynthetic capacity); and the stage when photosynthetic capacity started to decline and gradually changed to senescence. The two stages were then further subdivided into five intervals by gene expression clustering analysis: young leaves, the period of cell genesis and functional differentiation (L1); young leaves, the period of development and initial formation of photosynthetic capacity (L3–L7); the period of maximum photosynthetic capacity of functional leaves (L9–L13); the period of decreasing photosynthetic capacity of functional leaves (L15–L27); and the period of senescent leaves (L29). Using a weighted co-expression gene network analysis of regulatory genes, high-resolution spatiotemporal transcriptional regulatory networks were constructed to reveal the core regulators that regulate leaf development. Spatiotemporal transcriptome data of poplar leaves revealed dynamic changes in genes and miRNAs during leaf development and identified several core regulators of leaf development, such as GRF5 and MYB5. This in-depth analysis of transcriptional regulation during leaf development provides a theoretical basis for exploring the biological basis of the transcriptional regulation of leaf development and the molecular design of breeding for delaying leaf senescence.

Du Kang, a postdoctoral fellow at the College of Biological Science and Technology of Beijing Forestry University, is the first author of this paper, and Professor Kang Xiangyang is the corresponding author of this study.

This research was supported by the National Key R&D Program of China during the 14th Five-year Plan Period (2021YFD2200105).

Paper link: https://doi.org/10.1093/hr/uhad186