METHYLTRANSFERASE1 and Ripening Modulate Vivipary during Tomato Fruit Development

Area of Science:

• Plant biology
• Epigenetics
• Developmental biology

Background:

• Vivipary, or germination before dispersal, is an adaptation to harsh environments.
• While genetics of vivipary are known, the epigenetic role is unexplored.
• Dormancy typically prevents vivipary.

Purpose of the Study:

• Investigate the epigenetic mechanisms underlying vivipary in tomato.
• Determine the role of METHYLTRANSFERASE1 (SlMET1) in regulating seed dormancy and vivipary.

Main Methods:

• Utilized the tomato epimutant Colorless non-ripening (Cnr).
• Performed gene silencing of SlMET1 and SlNCED via virus-induced gene silencing and RNA interference.
• Analyzed changes in abscisic acid (ABA) concentration and gene expression.
• Identified differentially methylated regions in gene promoters.

Main Results:

• SlMET1 silencing in Cnr mutants induced vivipary and reduced ABA levels.
• Decreased SlNCED mRNA levels correlated with vivipary.
• Reversion of Cnr ripening suppressed vivipary.
• SlMET1 manipulation did not induce vivipary in wild-type tomatoes, but caused other developmental defects.

Conclusions:

• A dual pathway involving fruit ripening and SlMET1-mediated epigenetics regulates vivipary.
• SlMET1 plays a crucial role in epigenetic control of seed dormancy.
• Epigenetic mechanisms are key to understanding plant adaptations like vivipary.