Transcriptomic analyses show that 24-epibrassinolide (EBR) promotes cold tolerance in cotton seedlings.

Lingling Dou,Chaoyou Pang,Shuye Li,Yaru Sun,Guanghui Xiao,Qian Shen,Changwei Ge,Huaizhu Li,Wenbo Wang,Jiayi Mao,Mohammad Ansari

doi:10.1371/journal.pone.0245070

Abstract

In plants, brassinosteroids (BRs) are a class of steroidal hormones that are involved in numerous physiological responses. However, the function of BRs in cold tolerance in cotton has not been explored. In this study, cotton seedlings were treated with five concentrations (0, 0.05, 0.1, 0.2, 0.5 and 1.0 mg/L) of 24-Epibrassinolide (EBR) at 4°C. We measured the electrolyte leakage, malondialdehyde (MDA) content, proline content, and net photosynthesis rate (Pn) of the seedlings, which showed that EBR treatment increased cold tolerance in cotton in a dose-dependent manner, and that 0.2 mg/L is an optimum concentration for enhancing cold tolerance. The function of EBR in cotton cotyledons was investigated in the control 0 mg/L (Cold+water) and 0.2 mg/L (Cold+EBR) treatments using RNA-Seq. A total of 4,001 differentially expressed genes (DEGs), including 2,591 up-regulated genes and 1,409 down-regulated genes were identified. Gene Ontology (GO) and biochemical pathway enrichment analyses showed that EBR is involved in the genetic information process, secondary metabolism, and also inhibits abscisic acid (ABA) and ethylene (ETH) signal transduction. In this study, physiological experiments showed that EBR can increase cold tolerance in cotton seedlings, and the comprehensive RNA-seq data shed light on the mechanisms through which EBR increases cold tolerance in cotton seedlings.

Highlights

Cotton is a warm season crop that is sensitive to low temperatures, and it is one of the most important economic crops that is grown around the world because of its valuable textile fiber and edible seed oil
Cold stress first damages cell membranes and MDA is a product of lipid peroxidation, and increasing levels of MDA can further damage the cell membrane
The MDA content can reflect the relative degree of stress [35, 36]

Summary

Introduction

Cotton is a warm season crop that is sensitive to low temperatures, and it is one of the most important economic crops that is grown around the world because of its valuable textile fiber and edible seed oil. In China, Xinjiang is the main cotton fiber producing area, and cold stress is the major adverse factor that limits cotton production in the Xinjiang cotton-growing region. Transcriptomic analyses show that 24-epibrassinolide (EBR) promotes cold tolerance in cotton seedlings the National Natural Science Foundation of China (31872175, awarded to LD)

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Results

Conclusion