GmNAP1 is essential for trichome and leaf epidermal cell development in soybean

Kuanqiang Tang,Jinshan Gao,Yaohua Zhang,Xianzhong Feng,Jiantian Leng,Jingjing Ma,Suxin Yang,Huangkai Zhou,Tao Wu,Hui Yu,Xingxing Feng

doi:10.1007/s11103-020-01013-y

Abstract

Key messageMap-based cloning revealed that two novel soybean distorted trichome mutants were due to loss function of GmNAP1 gene, which affected the trichome morphology and pavement cell ploidy by regulating actin filament assembly.Trichomes increase both biotic and abiotic stress resistance in soybean. In this study, Gmdtm1-1 and Gmdtm1-2 mutants with shorter trichomes and bigger epidermal pavement cells were isolated from an ethyl methylsulfonate mutagenized population. Both of them had reduced plant height and smaller seeds. Map-based cloning and bulked segregant analysis identified that a G-A transition at the 3ʹ boundary of the sixth intron of Glyma.20G019300 in the Gmdtm1-1 mutant and another G-A transition mutation at the 5ʹ boundary of the fourteenth intron of Glyma.20G019300 in Gmdtm1-2; these mutations disrupted spliceosome recognition sites creating truncated proteins. Glyma.20G019300 encodes a Glycine max NCK-associated protein 1 homolog (GmNAP1) in soybean. Further analysis revealed that the GmNAP1 involved in actin filament assembling and genetic information processing pathways during trichome and pavement cell development. This study shows that GmNAP1 plays an important role in soybean growth and development and agronomic traits.

Highlights

Plant cells exhibit a wide variety of shapes that make important contributions to organ and tissue development and morphogenesis (Smith and Oppenheimer 2005; Yanagisawa et al 2015)
Two novel Glycine max distorted trichome mutant 1–1 and 1–2 (Gmdtm1-1 and 1-2) were characterized with visibly smoother leaf, and genetic mapping proved that Glycine max NCK-associated protein 1 homolog (GmNAP1) mutations cause abnormal trichome and pavement cell development in above two mutants
We further show that abnormal trichome shape and pavement size in Gmnap1 mutation involved the F-actin density in the trichome tip and the pavement cell ploidy, separately

Summary

Introduction

Plant cells exhibit a wide variety of shapes that make important contributions to organ and tissue development and morphogenesis (Smith and Oppenheimer 2005; Yanagisawa et al 2015). Many mutants of the SCAR/ WAVE complex have been identified in Arabidopsis, such as grl (gnarled)/nap (El-Assal Sel et al 2004), pir (pirogi) (Li et al 2004), sra ( rac1-associated protein 1) (Basu et al 2004), dis (distorted1) (Basu et al 2005), brk (brick1) (Folkers et al 2002), and spk (spike1) (Qiu et al 2002). A wild-type soybean NAP1 transgene functionally complemented an Arabidopsis nap mutant They proved that a historic spontaneous soybean gnarled trichrome mutant (T31) identified a frame shift mutation resulting in a truncation of the coding region of Glyma.20G019300. Two novel Glycine max distorted trichome mutant 1–1 and 1–2 (Gmdtm and 1-2) were characterized with visibly smoother leaf, and genetic mapping proved that GmNAP1 mutations cause abnormal trichome and pavement cell development in above two mutants. We further show that abnormal trichome shape and pavement size in Gmnap mutation involved the F-actin density in the trichome tip and the pavement cell ploidy, separately

Result

Discussion

Findings

Materials and methods