Soybean Gm SAUL1, a Bona Fide U-Box E3 Ligase, Negatively Regulates Immunity Likely through Repressing the Activation of Gm MPK3

Jun-Mei Li; Mei-Yan Ye; Chaofeng Wang; Xiao-Han Ma; Ni-Ni Wu; Chen-Li Zhong; Yanjun Zhang; Ninghui Cheng; Paul A Nakata; Lirong Zeng; Jian-Zhong Liu

doi:10.3390/ijms24076240

Soybean Gm SAUL1, a Bona Fide U-Box E3 Ligase, Negatively Regulates Immunity Likely through Repressing the Activation of Gm MPK3

Int J Mol Sci. 2023 Mar 25;24(7):6240. doi: 10.3390/ijms24076240.

Authors

Jun-Mei Li¹, Mei-Yan Ye^{1

2}, Chaofeng Wang³, Xiao-Han Ma¹, Ni-Ni Wu¹, Chen-Li Zhong¹, Yanjun Zhang¹, Ninghui Cheng⁴, Paul A Nakata⁴, Lirong Zeng³, Jian-Zhong Liu^{1

2}

Affiliations

¹ Institute of Plant Genetics and Developmental Biology, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
² Zhejiang Provincial Key Laboratory of Biotechnology on Specialty Economic Plants, Zhejiang Normal University, Jinhua 321004, China.
³ Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE 68588-0666, USA.
⁴ U.S. Department of Agriculture-Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.

Abstract

E3 ubiquitin ligases play important roles in plant immunity, but their role in soybean has not been investigated previously. Here, we used Bean pod mottle virus (BPMV)-mediated virus-induced gene silencing (VIGS) to investigate the function of GmSAUL1 (Senescence-Associated E3 Ubiquitin Ligase 1) homologs in soybean. When two closely related SAUL1 homologs were silenced simultaneously, the soybean plants displayed autoimmune phenotypes, which were significantly alleviated by high temperature, suggesting that GmSAUL1a/1b might be guarded by an R protein. Interestingly, silencing GmSAUL1a/1b resulted in the decreased activation of GmMPK6, but increased activation of GmMPK3 in response to flg22, suggesting that the activation of GmMPK3 is most likely responsible for the activated immunity observed in the GmSAUL1a/1b-silenced plants. Furthermore, we provided evidence that GmSAUL1a is a bona fide E3 ligase. Collectively, our results indicated that GmSAUL1 plays a negative role in regulating cell death and immunity in soybean.

Keywords: E3 ligase; Glycine max; GmSAUL1; cell death; immune responses; soybean; virus-induced gene silencing.

MeSH terms

Gene Expression Regulation, Plant
Glycine max* / physiology
Phenotype
Plant Immunity / genetics
Ubiquitin-Protein Ligases* / genetics
Ubiquitin-Protein Ligases* / metabolism

Substances

Ubiquitin-Protein Ligases

Grants and funding

This work was supported by grants from the National Natural Science Foundation of China (32170761 and 31571423 to J.-Z.L.) and by the US Department of Agriculture, Agricultural Research Service (under cooperative agreement number 58-3092-5-001 to P.A.N.). The contents of this publication do not necessarily reflect the views or policies of the US Department of Agriculture, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.