Dani Eshel Ph.D.

Bud dormancy is a survival strategy that plants have developed in their native habitats. It helps them endure harsh seasonal changes by temporarily halting growth and activity until conditions become more favorable. Research has primarily focused on bud dormancy in tree species and the ability to halt growth in vegetative tissues, particularly in meristems. Various plant species, such as Solanum tuberosum (potato), have developed specialized storage organs, enabling them to become dormant during their yearly growth cycle.

Deciduous trees and potato tubers exhibit a similar type of bud endodormancy, where the bud meristem will not initiate growth, even under favorable environmental conditions. Chilling accumulation activates C-repeat/dehydration-responsive element binding (DREB) factors (CBFs) transcription factors that modify the expression of dormancy-associated genes. Chilling conditions shorten the duration of endodormancy by influencing plant hormones and sugar metabolism, which affect the timing and rate of bud growth. Sugar metabolism and signaling pathways can interact with abscisic acid, affecting the symplastic connection of dormant buds.

In relation to dormancy, global warming has led to a chilling deficit during the winter, which could become a limiting factor in the near future for crop growth, particularly in the tropics and subtropics. We use the potato plant as a model system to study bud dormancy and vegetative growth. Since dormancy cannot be studied in classical plant models, the potato tuber offers a versatile and compact system for studying endodormancy under diverse temperatures and light conditions.

Sugar metabolism as a mechanism for abiotic stress tolerance

To cope with abiotic stress, plants have developed antioxidation strategies combined with osmoprotection by sugars.  Soluble sugars are important osmoprotectants that play a large role in cellular osmotic adjustment by protecting cell structures that are exposed to environmental stress. Potato tuber, a swollen stem, exposure to abiotic stress, such as cold stress, induces starch degradation and sucrose synthesis.

Using sugar metabolism CRISPR/Cas9 mutants, we have discovered alternative plant pathways that allow them to cope with abiotic stresses using other essential water‐soluble carbohydrates derived from sucrose include the raffinose family oligosaccharides (RFOs: α‐galactosyl extensions of sucrose). Sucrosyl oligosaccharides and the enzymes associated with their metabolism might interact indirectly with ROS-signaling pathways.

In this study, we integrate omics analyses with transgenic plants to understand the mechanisms leading to stress tolerance. This information is utilized in the development of genetically edited potato varieties with enhanced tolerance to a wide range of abiotic stresses.