Core clock component MtLUX controls shoot architecture through repression of MtTB1/MtTCP1A in Medicago truncatula
Liping Wang,
Anqi Zhou,
Lulu Wang,
Jing Li,
Mingkang Yang,
Tingting Duan,
Jian Jin,
Liang Chen,
Liangfa Ge,
Wei Huang
Affiliations
Liping Wang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Anqi Zhou
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Lulu Wang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Jing Li
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Mingkang Yang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Tingting Duan
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Jian Jin
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, Guangxi, China
Liang Chen
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China
Liangfa Ge
Department of Grassland Science, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Engineering Research Center for Grassland Science, Guangzhou 510642, Guangdong, China; Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangzhou 510642, Guangdong, China; Corresponding authors.
Wei Huang
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, China; Corresponding authors.
Plants are capable of regulating their shoot architecture in response to diverse internal and external environments. The circadian clock is an adaptive mechanism that integrates information from internal and ambient conditions to help plants cope with recurring environmental fluctuations. Despite the current understanding of plant circadian clock and genetic framework underlying plant shoot architecture, the intricate connection between these two adaptive mechanisms remains largely unclear. In this study, we elucidated how the core clock gene LUX ARRHYTHMO (LUX) regulates shoot architecture in the model legume plant Medicago truncatula. We show that mtlux mutant displays increased main stem height, reduced lateral shoot length, and decreased the number of lateral branches and biomass yield. Gene expression analysis revealed that MtLUX regulated shoot architecture by repressing the expression of strigolactone receptor MtD14 and MtTB1/MtTCP1A, a TCP gene that functions centrally in modulating shoot architecture. In vivo and in vitro experiments showed that MtLUX directly binds to a cis-element in the promoter of MtTB1/MtTCP1A, suggesting that MtLUX regulates branching by rhythmically suppressing MtTB1/MtTCP1A. This work demonstrates the regulatory effect of the circadian clock on shoot architecture, offering a new understanding underlying the genetic basis towards the flexibility of plant shoot architecture.
