Insights from the Cold Transcriptome and Metabolome of Dendrobium officinale: Global Reprogramming of Metabolic and Gene Regulation Networks during Cold Acclimation.

Song-Lin Chen,Zhi-Gang Wu,Wu Jiang,Cheng-Xi Jiang,Zheng-Ming Tao,Nitin Mantri

doi:10.3389/fpls.2016.01653

Song-Lin Chen, Zhi-Gang Wu + Show 4 more

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https://doi.org/10.3389/fpls.2016.01653

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Abstract

Plant cold acclimation (CA) is a genetically complex phenomenon involving gene regulation and expression. Little is known about the cascading pattern of gene regulatroy network and the link between genes and metabolites during CA. Dendrobium officinale (DOKM) is an important medicinal and ornamental plant and hypersensitive to low temperature. Here, we used the large scale metabolomic and transcriptomic technologies to reveal the response to CA in DOKM seedlings based on the physiological profile analyses. Lowering temperature from 4 to –2°C resulted in significant increase (P < 0.01) in antioxidant activities and electrolyte leakage (EL) during 24 h. The fitness CA piont of 0°C and control (20°C) during 20 h were firstly obtained according to physiological analyses. Subsequently, massive transcriptome and metabolome reprogramming occurred during CA. The gene to metabolite network demonstrated that the CA associated processes are highly energy demanding through activating hydrolysis of sugars, amino acids catabolism and citrate cycle. The expression levels of 2,767 genes were significantly affected by CA, including 153-fold upregulation of CBF transcription factor, 56-fold upregulation of MAPKKK16 protein kinase. Moreover, the gene interaction and regulation network analysis revealed that the CA as an active process, was regulated at the transcriptional, post-transcriptional, translational and post-translational levels. Our findings highligted a comprehensive regulatory mechanism including cold signal transduction, transcriptional regulation, and gene expression, which contributes a deeper understanding of the highly complex regulatory program during CA in DOKM. Some marker genes identified in DOKM seedlings will allow us to understand the role of each individual during CA by further functional analyses.

Highlights

Plants frequently encounter unfavorable growth conditions that jeoparadize its growth and affect productivity
To assess whether low temperature alters activities of several antioxidant enzymes in Dendrobium officinale Kimura and Migo (DOKM) seedlings, we monitored the responses to cold acclimation (CA) at 20◦C (Control), 4, 0, and −2◦C during 24 h
In plants subjected to CA, to enhance adaptability of plant to low temperature, high levels of sugars and ATP must be timely used to synthase COR proteins, lipids and membrance compositons, and to further promote cell membrane transport and structural rearrangement (Dobrota, 2006; Fristedt et al, 2015)

Summary

Introduction

Plants frequently encounter unfavorable growth conditions that jeoparadize its growth and affect productivity. Cold is a major stress that adversely affects plant growth and limits its geographical distribution and agricultural productivity (Boyer, 1982). The specie is extremely hypersensitive to low temperature above the freezing point, thereby resulting in major yeild losses (Lavarack et al, 2000). It is well known that many temperate herbaceous plants in nature, have evolved adaptive mechanisms to survive seasonal low winter temperature or sudden chilling (

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