AMPK activator 991 specifically activates SnRK1 and thereby affects seed germination in rice

Yuxiang Hu; Yan Lin; Jiaqi Bai; Xuemei Xu; Ziteng Wang; Chengqiang Ding; Yanfeng Ding; Lin Chen

doi:10.1093/jxb/erae046

AMPK activator 991 specifically activates SnRK1 and thereby affects seed germination in rice

J Exp Bot. 2024 Mar 11:erae046. doi: 10.1093/jxb/erae046. Online ahead of print.

Authors

Yuxiang Hu^{1

2}, Yan Lin^{1

2}, Jiaqi Bai^{1

2}, Xuemei Xu^{1

2}, Ziteng Wang^{1

2}, Chengqiang Ding^{1

2

3}, Yanfeng Ding^{1

2

3}, Lin Chen^{1

2

3}

Affiliations

¹ College of Agriculture, Nanjing Agricultural University, Nanjing, China.
² Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China.
³ Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry, Nanjing, China.

PMID: 38465908
DOI: 10.1093/jxb/erae046

Abstract

Sucrose non-fermenting-1-related protein kinase 1 (SnRK1) and AMP-activated protein kinase (AMPK) are highly conserved. Compound 991 is an AMPK activator in mammals. However, whether 991 also activates SnRK1 remains unknown. The addition of 991 significantly increased SnRK1 activity in desalted extracts from germinating rice seeds in vitro. To determine whether 991 has biological activity, rice seeds were treated with different concentrations of 991. Germination was promoted at low concentrations but inhibited at high concentrations. The effects of 991 on germination were similar to those of OsSnRK1a overexpression. To explore whether 991 affects germination by specifically affecting SnRK1, germination of an snrk1a mutant and wild type under 1 μM 991 treatment was compared. The snrk1a mutant was insensitive to 991. Phosphoproteomic analysis showed that the differential phosphopeptides induced by 991 and OsSnRK1a overexpression largely overlapped. Furthermore, SnRK1 might regulate rice germination in a dosage-dependent manner by regulating the phosphorylation of S285-PIP2;4, S1013-SOS1, and S110-ABI5. These results indicate that 991 is a specific SnRK1 activator in rice. The promotion and inhibition of germination by 991 also occurred in wheat seeds. Thus, 991 is useful for exploring SnRK1 function and the chemical regulation of growth and development in crops.

Keywords: AMPK; SnRK1; compound 991; germination; phosphoproteomics; rice.