Elucidating Cold-Tolerant Germination Mechanisms in Hulless Barley

A recent study published in BMC Genomics reveals new insights into the molecular and microbial mechanisms underlying cold-tolerant germination in hulless barley. Researchers from Longdong University, led by Panrong Ren, investigated the genetic and hormonal factors contributing to the remarkable natural cold adaptation of this crop. The study found that cold-tolerant hulless barley variety 37 exhibits enhanced resistance to low temperatures, with a germination rate decrease of only 2% compared to the cold-sensitive variety 44, which decreased by 69%. The research identified key genes, including late embryogenesis abundant protein (LEA) and Homeobox genes, that are involved in cold-tolerant germination.

Key Takeaways:

• The study identified 2,647 and 2,392 differentially expressed genes (DEGs) in cold-tolerant variety 37 and cold-sensitive variety 44, respectively, through transcriptome analysis.
• Weighted gene co-expression network analysis (WGCNA) revealed a green module positively correlated with gibberellic acid (GA) content, containing 10 core genes, including LEA and Homeobox genes.
• 16 S rRNA sequencing found enriched abundances of dominant endophytes, including Sphingomonas and Pelomonas, in cold-tolerant variety 37, with correlation coefficients of 0.70 and 0.87 with GA content, respectively.
• Exogenous GA treatment significantly increased germination rates under cold stress by 176.67% in cold-sensitive variety 44.
• The study suggests that the enhanced cold tolerance of hulless barley during seed germination originates from the synergistic interaction between beneficial endophytes, GA, and core genes, such as LEA and Homeobox.

Statistics:

• Cold-tolerant variety 37 exhibited 2% decrease in germination rate under low temperatures, while cold-sensitive variety 44 decreased by 69%.
• Transcriptome analysis identified 2,647 and 2,392 DEGs in variety 37 and 44, respectively.
• WGCNA analysis revealed 10 core genes involved in cold-tolerant germination, including LEA and Homeobox genes.
• 16 S rRNA sequencing found enriched abundances of dominant endophytes, including Sphingomonas and Pelomonas, in cold-tolerant variety 37 (abundance: 0.70, correlation coefficient: 0.70; abundance: 0.87, correlation coefficient: 0.87).
• Exogenous GA treatment significantly increased germination rates under cold stress by 176.67% in cold-sensitive variety 44.

Sources:

• Ren, P., et al. (2025). Integrated 16 S rRNA and transcriptome analysis reveal molecular and microbial mechanisms of cold-tolerant germination in hulless barley. BMC Genomics, 26(1), 906.
• BMC Genomics. (2025). BMC Genomics. 4 Crinan St, London N1 9XW, England.