Desiccation tolerance in bryophytes: The dehydration and rehydration transcriptomes in the desiccation-tolerant bryophyte Bryum argenteum

Bei Gao,Daoyuan Zhang,Yuqing Liang,Jianhua Zhang,Moxian Chen,Yuanming Zhang,Xiaoshuang Li,Andrew J Wood,Honglan Yang

doi:10.1038/s41598-017-07297-3

Abstract

The desiccation tolerant bryophyte Bryum argenteum is an important component of desert biological soil crusts (BSCs) and is emerging as a model system for studying vegetative desiccation tolerance. Here we present and analyze the hydration-dehydration-rehydration transcriptomes in B. argenteum to establish a desiccation-tolerance transcriptomic atlas. B. argenteum gametophores representing five different hydration stages (hydrated (H0), dehydrated for 2 h (D2), 24 h (D24), then rehydrated for 2 h (R2) and 48 h (R48)), were sampled for transcriptome analyses. Illumina high throughput RNA-Seq technology was employed and generated more than 488.46 million reads. An in-house de novo transcriptome assembly optimization pipeline based on Trinity assembler was developed to obtain a reference Hydration-Dehydration-Rehydration (H-D-R) transcriptome comprising of 76,206 transcripts, with an N50 of 2,016 bp and average length of 1,222 bp. Comprehensive transcription factor (TF) annotation discovered 978 TFs in 62 families, among which 404 TFs within 40 families were differentially expressed upon dehydration-rehydration. Pfam term enrichment analysis revealed 172 protein families/domains were significantly associated with the H-D-R cycle and confirmed early rehydration (i.e. the R2 stage) as exhibiting the maximum stress-induced changes in gene expression.

Highlights

The desiccation tolerant moss Bryum argenteum is emerging as an important model organism for understanding the molecular, structural and ecological aspects of vegetative desiccation tolerance in plants[1,2,3,4], and is an important component of the biological soil crusts found in Northwestern China[5]
Vegetative Desiccation tolerant (DT) in bryophytes is a common phenotype and understanding the molecular basis of the phenotype is predicated upon expanding our inquiry to other exemplar species such as B. argenteum
We generated an optimized de novo transcriptome assembly and analyzed the gene expression profiles of B. argenteum subjected to a detailed H-D-R cycle

Summary

Introduction

The desiccation tolerant moss Bryum argenteum is emerging as an important model organism for understanding the molecular, structural and ecological aspects of vegetative desiccation tolerance in plants[1,2,3,4], and is an important component of the biological soil crusts found in Northwestern China[5]. MRNA transcripts are sequestered in messenger ribonucleoprotien particles (mRNPs) and stably maintained in desiccated tissues[13] Upon rehydration, these masked transcripts are preferentially selected and translated through activation of a repair-based mechanism. Our research group generated a de novo transcriptome for B. argenteum and analyzed digital gene expression (DGE) comparing three hydration stages (i.e., desiccated, 2 h post-rehydration and 24 h post-rehydration), in which neither hydration control nor biological replicates were conducted[1]. We generated an optimized and robust transcriptome assembly and analyzed gene expression (DGE) by comparing an expanded number of hydration stages for cultured B. argenteum gametophores: hydrated, dehydrated 2 h, dehydrated 24 h, rehydrated 2 h and rehydrated 48 h. The data presented will provide greater insight into gene expression as plant tissues dehydrate/rehydrate and reveal molecular alterations associated with vegetative desiccation tolerance

Methods

Results

Conclusion