Epigenetic Variability Among Saffron Crocus (Crocus sativus L.) Accessions Characterized by Different Phenotypes

Area of Science:

• Plant epigenetics
• Molecular genetics
• Agricultural science

Background:

• Saffron crocus (Crocus sativus) exhibits diverse phenotypes in tepal pigmentation, yield, and flowering time.
• Understanding the molecular basis of these variations is crucial for saffron improvement.

Purpose of the Study:

• To conduct the first epigenomic study on saffron crocus.
• To investigate epigenetic and genetic variability among different saffron accessions.
• To identify potential molecular markers associated with phenotypic differences.

Main Methods:

• Methylation-sensitive restriction enzyme-sequencing (MRE-seq) to generate hypomethylomes.
• Sequence assembly and annotation using the rice genome as a reference.
• Single Nucleotide Polymorphism (SNP) detection and Gene Ontology (GO) analysis.

Main Results:

• High epigenetic variability was confirmed, with numerous differentially methylated regions identified.
• Key genes involved in flowering (MADS-box, TFL) and pigment production (MYB) showed epigenetic variation.
• Surprisingly high genetic variability, indicated by numerous SNPs, was detected, likely due to vegetative propagation.
• Distinct patterns of polymorphic GOs were observed among accessions based on geographic origin, suggesting selection signatures.

Conclusions:

• Epigenetic and genetic variability contribute to the diverse phenotypes observed in saffron crocus.
• The study identified candidate genes and molecular markers for saffron breeding.
• Geographic origin influences genetic polymorphism patterns, indicating potential selection pressures.