Strigolactones modulate stem length and diameter of cherry rootstocks through interaction with other hormone signaling pathways

Xunju Liu; Yan Xu; Wanxia Sun; Jiyuan Wang; Yixin Gao; Lei Wang; Wenping Xu; Shiping Wang; Songtao Jiu; Caixi Zhang

doi:10.3389/fpls.2023.1092654

Strigolactones modulate stem length and diameter of cherry rootstocks through interaction with other hormone signaling pathways

Front Plant Sci. 2023 Feb 9:14:1092654. doi: 10.3389/fpls.2023.1092654. eCollection 2023.

Authors

Xunju Liu¹, Yan Xu¹, Wanxia Sun¹, Jiyuan Wang¹, Yixin Gao¹, Lei Wang¹, Wenping Xu¹, Shiping Wang¹, Songtao Jiu¹, Caixi Zhang¹

Affiliation

¹ Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.

Abstract

Stem growth and development has considerable effects on plant architecture and yield performance. Strigolactones (SLs) modulate shoot branching and root architecture in plants. However, the molecular mechanisms underlying SLs regulate cherry rootstocks stem growth and development remain unclear. Our studies showed that the synthetic SL analog rac-GR24 and the biosynthetic inhibitor TIS108 affected stem length and diameter, aboveground weight, and chlorophyll content. The stem length of cherry rootstocks following TIS108 treatment reached a maximum value of 6.97 cm, which was much higher than that following rac-GR24 treatments at 30 days after treatment. Stem paraffin section showed that SLs affected cell size. A total of 1936, 743, and 1656 differentially expressed genes (DEGs) were observed in stems treated with 10 μM rac-GR24, 0.1 μM rac-GR24, and 10 μM TIS108, respectively. RNA-seq results highlighted several DEGs, including CKX, LOG, YUCCA, AUX, and EXP, which play vital roles in stem growth and development. UPLC-3Q-MS analysis revealed that SL analogs and inhibitors affected the levels of several hormones in the stems. The endogenous GA₃ content of stems increased significantly with 0.1 μM rac-GR24 or 10 μM TIS108 treatment, which is consistent with changes in the stem length following the same treatments. This study demonstrated that SLs affected stem growth of cherry rootstocks by changing other endogenous hormone levels. These results provide a solid theoretical basis for using SLs to modulate plant height and achieve sweet cherry dwarfing and high-density cultivation.

Keywords: cherry rootstocks; differentially expressed genes; stem growth and development; strigolactones; transcriptomics.

Grants and funding

This work was funded by Shanghai Agriculture Applied Technology Development Program, China (Grant No. 2022-02-08-00-12-F01111), China Agriculture Research System (CARS-30-2-08), National Natural Science Foundation of China (NSFC) (Grant No. 32102347), Shanghai Sailing Program (Grant No. 21YF1422100), and the Startup Fund for Young Faculty at SJTU (Grant No. 21X010500643).