MiR168 targets Argonaute1A mediated miRNAs regulation pathways in response to potassium deficiency stress in tomato

Xin Liu,Chunchang Tan,Xin Cheng,Xiaoming Zhao,Jing Jiang,Tianlai Li

doi:10.1186/s12870-020-02660-5

Abstract

BackgroundPotassium (K+) is an essential ion for most plants, as it is involved in the regulation of growth and development. K+ homeostasis in plant cells has evolved to facilitate plant adaptation to K+-deficiency stress. Argonaute1 (AGO1) is regulated by miR168 to modulate the small RNA regulatory pathway by RNA silencing complex (RISC) in tomatoes. However, the role of miR168-mediated regulation of AGO1 in the context of K+ deficiency stress in tomatoes has not been elucidated yet.ResultsSlmiR168 and its target gene SlAGO1A were differentially expressed among low-K+-tolerant JZ34 and low-K+-sensitive JZ18 tomato plants. Transgenic tomato plants constitutively expressing pri-SlmiR168a showed stronger root system growth, better leaves development, and higher K+ contents in roots under K+-deficiency stress than those of the transgenic tomato lines expressing rSlAGO1A (SlmiR168-resistant) and the wild type (WT). Deep sequencing analysis showed that 62 known microRNAs (miRNAs) were up-regulated in 35S:rSlAGO1 compared with WT tomatoes. The same miRNAs were down-regulated in 35S:SlmiR168a compared with WT plants. The integrated analysis found 12 miRNA/mRNA pairs from the 62 miRNAs, including the root growth and cytokinin (CTK)/abscisic acid (ABA) pathways.ConclusionsThe regulation mediated by SlmiR168 of SlAGO1A contributes to the plant development under low-K+ stress. Moreover, this regulation mechanism may influence downstream miRNA pathways in response to low-K+ stress through the CTK/ABA and root growth modulation pathways.

Highlights

Potassium (K+) is an essential ion for most plants, as it is involved in the regulation of growth and development
We aimed to evaluate the balance between SlmiR168 and SlAGO1 (SlAGO1A) expression in response to K+ deficiency stress in Solanum lycopersicum
According to our previous study, SlmiR168 is differentially expressed between JZ18 and JZ34 tomatoes under K+ deficiency stress

Summary

Introduction

Potassium (K+) is an essential ion for most plants, as it is involved in the regulation of growth and development. Argonaute (AGO1) is regulated by miR168 to modulate the small RNA regulatory pathway by RNA silencing complex (RISC) in tomatoes. The role of miR168-mediated regulation of AGO1 in the context of K+ deficiency stress in tomatoes has not been elucidated yet. Macronutrients and micronutrients are the elements required necessarily for growth and development of plants [1]. N (Nitrogen), P (Phosphorus) and K (Potassium) were needed at relatively large amounts for plants. Phosphorus deficiency could reduces the plant growth. These functions rely on a high and relatively stable concentration of K+ in cellular compartments and K+.

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