Sucrose promotes D53 accumulation and tillering in rice

Abstract

Summary Shoot branching is regulated by multiple signals. Previous studies have indicated that sucrose may promote shoot branching through suppressing the inhibitory effect of the hormone strigolactone (SL). However, the molecular mechanisms underlying this effect are unknown. Here, we used molecular and genetic tools to identify the molecular targets underlying the antagonistic interaction between sucrose and SL. We showed that sucrose antagonizes the suppressive action of SL on tillering in rice and on the degradation of D53, a major target of SL signalling. Sucrose inhibits the gene expression of D3, the orthologue of the Arabidopsis F‐box MAX2 required for SL signalling. Overexpression of D3 antagonizes sucrose inhibition of D53 degradation and enables the SL inhibition of tillering under high sucrose. Sucrose prevents SL‐induced degradation of D14, the SL receptor involved in D53 degradation. In contrast to D3, D14 overexpression enhances D53 protein levels and sucrose‐induced tillering, even in the presence of SL. Our results show that sucrose inhibits SL response by affecting key components of SL signalling and, together with previous studies reporting the inhibition of SL synthesis by nitrate and phosphate, demonstrate the central role played by SLs in the regulation of plant architecture by nutrients.

Biological Functions of Strigolactones and Their Crosstalk With Other Phytohormones

“…Therefore, along with induced activation of OsCKX9, SLs may affect the CK content through crosstalk with auxin. In addition, high sugar levels were found to inhibit SL perception, notably by directly targetting SL signalling ( Dierck et al, 2016 ; Bertheloot et al, 2020 ; Patil et al, 2021 ). Sugars were also found to upregulate the levels of CK, which acts antagonistically with SLs ( Barbier et al, 2015 ; Kiba et al, 2019 ; Salam et al, 2021 ).…”

Fine-mapping and candidate gene analysis of a major locus controlling leaf thickness in rice (Oryza sativa L.)

“…There are about 687 potential F-box proteins in rice controlling the degradation of cellular proteins in rice (Paterson et al 1993 ). Some of them encoded phytohormone important signaling transduction regulators, such as TIR1 , COI1 , GID2 , and MAX2 (Tao et al 2017 ; Guo et al 2021 ; Liu et al 2021 ; Patil et al 2021 ). Moreover, a small beta-glucosidase cluster is also presented in the candidate region.…”

Cyclanilide Induces Lateral Bud Outgrowth by Modulating Cytokinin Biosynthesis and Signalling Pathways in Apple Identified via Transcriptome Analysis

“…Sucrose and CTKs could establish directional auxin transport in axillary buds [ 40 ]. Patil et al revealed that sucrose suppressed the inhibitory effect of SL by promoting D53 accumulation [ 52 ]. Trehalose-6-phosphate synthase showed a higher expression level after CYC treatment than control ( Table 1 ).…”