Integrative analysis of physiology, biochemistry and transcriptome reveals the mechanism of leaf size formation in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

Lixia Wang; Shu Zhang; Ye Zhang; Jingjuan Li; Yihui Zhang; Dandan Zhou; Cheng Li; Lilong He; Huayin Li; Fengde Wang; Jianwei Gao

doi:10.3389/fpls.2023.1183398

Integrative analysis of physiology, biochemistry and transcriptome reveals the mechanism of leaf size formation in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

Front Plant Sci. 2023 Apr 6:14:1183398. doi: 10.3389/fpls.2023.1183398. eCollection 2023.

Authors

Lixia Wang¹, Shu Zhang¹, Ye Zhang², Jingjuan Li¹, Yihui Zhang¹, Dandan Zhou^{1

3}, Cheng Li¹, Lilong He¹, Huayin Li¹, Fengde Wang¹, Jianwei Gao¹

Affiliations

¹ Institute of Vegetables, Shandong Academy of Agricultural Sciences, Jinan, China.
² College of Life Science, Huangshan University, Huangshan, China.
³ College of Life Sciences, Shandong Normal University, Jinan, China.

Abstract

Introduction: The leaf, the main product organ, is an essential factor in determining the Chinese cabbage growth, yield and quality.

Methods: To explore the regulatory mechanism of leaf size development of Chinese cabbage, we investigated the leaf size difference between two high-generation inbred lines of Chinese cabbage, Y2 (large leaf) and Y7 (small leaf). Furtherly, the transcriptome and cis-acting elements analyses were conducted.

Results and discussion: According to our results, Y2 exhibited a higher growth rate than Y7 during the whole growth stage. In addition, the significant higher leaf number was observed in Y2 than in Y7. There was no significant difference in the number of epidermal cells and guard cells per square millimeter between Y2 and Y7 leaves. It indicated that cell numbers caused the difference in leaf size. The measurement of phytohormone content confirmed that GA1 and GA3 mainly play essential roles in the early stage of leaf growth, and IPA and ABA were in the whole leaf growth period in regulating the cell proliferation difference between Y2 and Y7. Transcriptome analysis revealed that cyclins BraA09g010980.3C (CYCB) and BraA10g027420.3C (CYCD) were mainly responsible for the leaf size difference between Y2 and Y7 Chinese cabbage. Further, we revealed that the transcription factors BraA09gMYB47 and BraA06gMYB88 played critical roles in the difference of leaf size between Y2 and Y7 through the regulation of cell proliferation.

Conclusion: This observation not only offers essential insights into understanding the regulation mechanism of leaf development, also provides a promising breeding strategy to improve Chinese cabbage yield.

Keywords: Chinese cabbage; MYB transcription factor; cell cycle; cyclins; leaf size.

Grants and funding

This study was supported by the Taishan Scholars Program of Shandong Province, China (tsqn201909167); Nature Foundation of Shandong Province (ZR2022QC113); Agricultural Science and Technology Innovation Project of SAAS (CXGC2022E08); Modern Agricultural Industrial Technology System Funding of Shandong Province, China (SDAIT-05); Agricultural Science and Technology Innovation Project of SAAS, China (CXGC2022D01); and the Prospect of Shandong Seed Project, China (2022LZGC008).