Ectopic expression of Triticum aestivum SERK genes (TaSERKs) control plant growth and development in Arabidopsis

Akanksha Singh,Paramjit Khurana

doi:10.1038/s41598-017-10038-1

Akanksha Singh, Paramjit Khurana

Open Access

https://doi.org/10.1038/s41598-017-10038-1

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Journal: Scientific Reports	Publication Date: Sep 28, 2017
Citations: 29	License type: open-access

Affiliation: University of Delhi

Abstract

Somatic embryogenesis receptor kinases (SERKs) belong to a small gene family of receptor-like kinases involved in signal transduction. A total of 54 genes were shortlisted from the wheat genome survey sequence of which 5 were classified as SERKs and 49 were identified as SERK-like (SERLs). Tissue- specific expression of TaSERKs at major developmental stages of wheat corroborates their indispensable role during somatic and zygotic embryogenesis. TaSERK transcripts show inherent differences in their hormonal sensitivities, i.e. TaSERK2 and TaSERK3 elicits auxin- specific responses while TaSERK1, 4 and 5 were more specific towards BR-mediated regulation. The ectopic expression of TaSERK1, 2, 3, 4 and 5 in Arabidopsis led to enhanced plant height, larger silique size and increased seed yield. Zygotic embryogenesis specific genes showed a differential pattern in TaSERK Arabidopsis transgenics specifically in the silique tissues. Elongated hypocotyls and enhanced root growth were observed in the overexpression transgenic lines of all five TaSERKs. The inhibitory action of auxin and brassinosteroid in all the TaSERK transgenic lines indicates their role in regulating root development. The results obtained imply redundant functions of TaSERKs in maintaining plant growth and development.

Highlights

Somatic embryogenesis (SE) is the developmental reprogramming of somatic cells towards the embryogenic pathway which forms the basis of cellular totipotency in higher plants[1,2]
From the above sequence analysis, we identified five SOMATIC EMBRYOGENESIS RECEPTOR LIKE KINASE (SERK) which were named as TaSERK1
TaSERK1 and TaSERK5 were induced significantly to a high extent in the presence of BR. These results suggest that the TaSERK2 response is highly auxin mediated compared to other TaSERKs, while TaSERK1 and TaSERK5 may be mediated by the BR signaling pathway, consistent with AtSERK1, 2, 3 and 452

Summary

Introduction

Somatic embryogenesis (SE) is the developmental reprogramming of somatic cells towards the embryogenic pathway which forms the basis of cellular totipotency in higher plants[1,2]. SOMATIC EMBRYOGENESIS RECEPTOR LIKE KINASE (SERK) first isolated from carrot (Daucus carota) embryogenic cells, is considered a characteristic molecular marker for SE in carrot, Dactylis glomerata and Arabidopsis[4,5,20]. Since it is expressed in somatic cultures exhibiting close homology with animal and plant receptor kinases, it was named as somatic embryogenesis receptor kinase (SERK) gene. In P. notatum, PnSERK2 was correlated with the onset of apomixis as it showed expression in nucellar cells at the meiosis stage of the apomictic genotype[32] These studies substantiate that the SERK genes play a crucial role during embryogenesis and have functional relevance in other facets of plant growth and development. Constitutive expression of TaSERKs in Arabidopsis results in enhanced hypocotyl length, plant height, altered silique size and seed yield

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