BpTCP3 Transcription Factor Improves Salt Tolerance of Betula platyphylla by Reducing Reactive Oxygen Species Damage

Abstract

The plant-specific transcription factors TEOSINTE BRANCHED1/CYCLO IDEA/PROLIFERATING CELL FACTOR1 (TCP) act as developmental regulators that have many roles in the growth and development processes throughout the entire life span of plants. TCP transcription factors are responsive to endogenous and environmental signals, such as salt stress. However, studies on the role of the TCP genes in salt stress response have rarely focused on woody plants, especially forest trees. In this study, the BpTCP3 gene, a CYC/TB1 subfamily member, isolated from Betula platyphylla Sukaczev, was significantly influenced by salt stress. The β-glucuronidase (GUS) staining analysis of transgenic B. platyphylla harboring the BpTCP3 promoter fused to the reporter gene GUS (pBpTCP3::GUS) further confirmed that the BpTCP3 gene acts a positive regulatory position in salt stress. Under salt stress, we found that the BpTCP3 overexpressed lines had increased relative/absolute high growth but decreased salt damage index, hydrogen peroxide (H2O2), and malondialdehyde (MDA) levels versus wild-type (WT) plants. Conversely, the BpTCP3 suppressed lines exhibited sensitivity to salt stress. These results indicate that the BpTCP3 transcription factor improves the salt tolerance of B. platyphylla by reducing reactive oxygen species damage, which provides useful clues for the functions of the CYC/TB1 subfamily gene in the salt stress response of B. platyphylla.

Genome-Wide Analysis of the TCP Gene Family and Their Expression Pattern Analysis in Tea Plant (Camellia sinensis)

“…In rice, most of the PCF group (group 1) genes participate in the stress response, OsPCF6 and OsTCP21 expression were largely induced by cold stress, and the downregulation of OsPCF6 and OsTCP21 resulted in enhanced tolerance to cold stress (Wang et al, 2014), and OsPCF5/OsPCF8 (Yang et al, 2013) and OsTCP19 (Mukhopadhyay and Tyagi, 2015) play the important roles in the stress response. In other plant species, TCP genes involved in abiotic stress response mostly belong to PCF group, such as in Phyllostachys edulis (Liu et al, 2020), Glycine max (Ling et al, 2020), Betula platyphylla (Li et al, 2020;Ren et al, 2021), and so on. In the evolutionary tree, TCP family of tea plant and Arabidopsis can be divided into 9 clades (Supplementary Figure 5).…”

Salt Tolerance Evaluation of Cucumber Germplasm under Sodium Chloride Stress

“…Consequently, the salt damage index has been used to select salt-tolerant germplasms in pumpkin [ 57 ]. In addition to the salt damage index, hydrogen peroxide and malondialdehyde contents have also been used as important indexes to evaluate the salt tolerance of birch [ 58 ]. Generally, the degree of salt-damage increases with the salt damage index under salt stress; thus, the higher the salt damage index, the lower the salt tolerance.…”