Mutation in BrEPCR1 Led to Early Flowering in Chinese Cabbage

Area of Science:

• Plant genetics
• Molecular biology
• Crop science

Background:

• Flowering time is a crucial agricultural trait in Chinese cabbage, especially for stalk-type varieties.
• Early flowering mutants can accelerate crop maturity and improve adaptability to diverse environments.

Purpose of the Study:

• To identify and characterize the genetic basis of early flowering in Chinese cabbage mutants.
• To elucidate the molecular mechanism underlying the early flowering phenotype.

Main Methods:

• MutMap and KASP genotyping for gene identification.
• Sequencing analysis of allelic mutants and transient transformation for functional validation.
• Chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) to assess histone modification levels.

Main Results:

• Two allelic early flowering mutants, efm1 and efm2, were characterized and found to be insensitive to photoperiod, vernalization, and GA3 treatments.
• The causal gene, BrEPCR1, a homolog of Arabidopsis EPCR1, was identified and validated.
• BrEPCR1 acts as a polycomb-related protein, involved in histone deacetylation and heterochromatin silencing, with decreased H4K5ac levels observed at BrFLC2/3 in the efm1 mutant.
• The EPL domain of BrEPCR1 is essential for its interaction with BrMBD9.

Conclusions:

• BrEPCR1 plays a significant role in regulating flowering time in Chinese cabbage.
• The identified gene and its function provide insights into the molecular mechanisms controlling flowering time.
• Brepcr1 has potential applications in promoting early maturity in stalk-type Chinese cabbage cultivars.