Transcriptome Sequencing of Dianthus spiculifolius and Analysis of the Genes Involved in Responses to Combined Cold and Drought Stress.

Aimin Zhou,Jingang Wang,Shufang Gong,Enhui Liu,Tongtong Jiang,Shuang Feng,Hongping Ma

doi:10.3390/ijms18040849

Abstract

Dianthus spiculifolius, a perennial herbaceous flower and a member of the Caryophyllaceae family, has strong resistance to cold and drought stresses. To explore the transcriptional responses of D. spiculifolius to individual and combined stresses, we performed transcriptome sequencing of seedlings under normal conditions or subjected to cold treatment (CT), simulated drought treatment (DT), or their combination (CTDT). After de novo assembly of the obtained reads, 112,015 unigenes were generated. Analysis of differentially expressed genes (DEGs) showed that 2026, 940, and 2346 genes were up-regulated and 1468, 707, and 1759 were down-regulated in CT, DT, and CTDT samples, respectively. Among all the DEGs, 182 up-regulated and 116 down-regulated genes were identified in all the treatment groups. Analysis of metabolic pathways and regulatory networks associated with the DEGs revealed overlaps and cross-talk between cold and drought stress response pathways. The expression profiles of the selected DEGs in CT, DT, and CTDT samples were characterized and confirmed by quantitative RT-PCR. These DEGs and metabolic pathways may play important roles in the response of D. spiculifolius to the combined stress. Functional characterization of these genes and pathways will provide new targets for enhancement of plant stress tolerance through genetic manipulation.

Highlights

Adverse environmental conditions seriously affect the growth and development of plants
Investigations into the effects of stress have generally examined the responses to individual abiotic stresses [1,2]; abiotic stresses rarely occur individually and plants are often simultaneously exposed to a combination of stresses such as cold and drought
Transcriptome Sequencing of D. spiculifolius Subjected to Cold, Drought, and Combined Cold and Drought Stress

Summary

Introduction

Adverse environmental conditions seriously affect the growth and development of plants. The molecular mechanisms associated with plant responses to combined cold and drought stresses, such as changes in gene expression, signal transduction and regulatory networks, are largely unknown. In Arabidopsis, plants with mutation in ein (ethylene insensitive) and aba1.6 (abscisic acid) show differential regulation of 2313 and 4131 transcripts, respectively, under cold and drought stress. Validation of some of the important differentially expressed genes (DEGs) showed that HSPs (heat shock proteins), COR47 (cold regulated proteins), and SPX1 (SPX domain containing proteins) were altered by stress in ein and aba1.6 mutants [11]. Drought-induced leaf senescence is affected by the expression of senescence-associated genes and cold responsive genes and by the regulation of multiple metabolic pathways in response to a combined stress [14]

Methods

Results

Conclusion