Molecular Traits for Adaptation to Drought and Salt Stress in Birch, Oak and Poplar Species

Abstract

Betula spp., Quercus spp., and Populus spp. are the most promising deciduous woody plants in forestry. However, these species were found to be sensitive to climate change that can badly affect their plantations. Thus, a deep understanding of genetic mechanisms of adaptation to adverse environmental conditions plays an important role in preventing the reduction of deciduous forest area. This mini review describes the stress responses of Betula spp., Quercus spp., and Populus spp. to drought and salt stresses. The overall stress response of the reviewed tree species includes ROS scavenging, ABA- and JA-mediated signaling pathways, and antioxidant and chaperone activities. Short-term drought promotes accumulation of proline, indicating the osmotic stress response. In turn, long-term drought stress activates the DNA repair and chromatin remodeling systems aimed at adapting and gene protecting. Furthermore, alternative pathways of carbohydrate production are used under nutrient deficiencies. It should be noted that stomatal movement control and cell wall remodeling are always observed during drought. In turn, the main response to salt stress includes the maintenance of ion homeostasis and the accumulation of osmoprotectant, as well as cell wall remodeling due to the biosynthesis of cellulotic and non-cellulotic cell wall compounds. It should be noted that the described species demonstrate similar molecular traits for adaptation to drought and salt stress, which may be due to their common habitats.

Enhancing Salt Tolerance in Poplar Seedlings through Arbuscular Mycorrhizal Fungi Symbiosis

“…Popular is a valuable tree species with economic significance, but salt stress adversely affects its physiology, growth, and productivity. Throughout the course of evolution, poplar trees have developed various mechanisms to adapt to salt stress [ 22 ]. Mycorrhizal symbiosis plays a crucial role in establishing a mutualistic relationship between poplar trees and fungi, assisting plants in coping with adverse environmental conditions through different mechanisms [ 23 ].…”

Genome-Wide Characterization of bHLH Family Genes and Expression Analysis in Response to Osmotic Stress in Betula platyphylla

“…Transcription factors (TFs), also known as trans-acting factors, refer to DNA-binding proteins that can specifically interact with cis-acting elements of eukaryotic genes and activate or inhibit gene transcription. TFs play a key role in the stress response regulation network and signal pathway in eukaryotic organisms and activate the plant's response to environmental changes by regulating the expression of resistance-related genes [5].…”