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

Area of Science:

• Plant Science
• Molecular Biology
• Agricultural Science

Background:

• Brassinosteroids (BRs) are crucial plant steroidal hormones regulating diverse physiological processes.
• The role of BRs in cotton cold tolerance remains largely unexplored.
• Understanding cold stress responses is vital for improving crop resilience.

Purpose of the Study:

• To investigate the effect of 24-Epibrassinolide (EBR) on cold tolerance in cotton seedlings.
• To determine the optimal EBR concentration for enhancing cold resistance.
• To elucidate the molecular mechanisms underlying EBR-mediated cold tolerance using RNA-Seq.

Main Methods:

• Cotton seedlings were treated with varying concentrations of 24-Epibrassinolide (EBR) under cold stress (4°C).
• Physiological parameters including electrolyte leakage, MDA content, proline content, and net photosynthesis rate (Pn) were measured.
• RNA-sequencing (RNA-Seq) was employed to analyze gene expression profiles in cotyledons under cold stress with and without EBR treatment.

Main Results:

• EBR treatment significantly enhanced cold tolerance in cotton seedlings in a dose-dependent manner.
• An optimal EBR concentration of 0.2 mg/L was identified for maximum cold tolerance enhancement.
• RNA-Seq analysis revealed 4,001 differentially expressed genes (DEGs), with 2,591 up-regulated and 1,409 down-regulated.
• Enrichment analyses indicated EBR's involvement in genetic information processing, secondary metabolism, and inhibition of abscisic acid (ABA) and ethylene (ETH) signaling.

Conclusions:

• 24-Epibrassinolide (EBR) effectively improves cold tolerance in cotton seedlings.
• EBR influences cold tolerance through modulation of gene expression and key hormonal pathways (ABA, ETH).
• This study provides valuable insights into the molecular basis of BR-mediated cold acclimation in cotton.