The MYB transcription factor (TF) family is one of the largest transcription families in plants, which is widely involved in the responses of plants to biotic and abiotic stresses, as well as plant growth, development, and metabolic regulation. In the present study, a new MYB TF gene, MbMYB108, from Malus baccata (L.) Borkh, was identified and characterized. The open reading frame (ORF) of MbMYB108 was found to be 903 bp, encoding 300 amino acids. Sequence alignment results and predictions of the protein structure indicated that the MbMYB108 protein contained the conserved MYB domain. Subcellular localization showed that MbMYB108 was localized to the nucleus. The expression of MbMYB108 was enriched in young and mature leaves, and was highly affected by cold and drought treatments in M. baccata seedlings. When MbMYB108 was introduced into Arabidopsis thaliana, it greatly increased the cold and drought tolerances in the transgenic plant. Increased expression of MbMYB108 in transgenic A. thaliana also resulted in higher activities of peroxidase (POD) and catalase (CAT), higher contents of proline and chlorophyll, while malondialdehyde (MDA) content and relative conductivity were lower, especially in response to cold and drought stresses. Therefore, these results suggest that MbMYB108 probably plays an important role in the response to cold and drought stresses in A. thaliana by enhancing the scavenging capability for reactive oxygen species (ROS).

The MYB transcription factor (TF) family is one of the largest transcription families in plants, which is widely involved in the responses to different abiotic stresses, such as salt, cold, and drought. In the present study, a new MYB TF gene was cloned from Fragaria vesca (a diploid strawberry) and named FvMYB82. The open reading frame (ORF) of FvMYB82 was found to be 960 bp, encoding 319 amino acids. Sequence alignment results and predictions of the protein structure indicated that the FvMYB82 contained the conserved R2R3-MYB domain. Subcellular localization analysis showed that FvMYB82 was localized onto the nucleus. Furthermore, the qPCR showed that the expression level of FvMYB82 was higher in new leaves and roots than in mature leaves and stems. When dealing with different stresses, the expression level of FvMYB82 in F. vesca seedlings changed markedly, especially for salt and cold stress. When FvMYB82 was introduced into Arabidopsis thaliana, the tolerances to salt and cold stress of FvMYB82-OE A. thaliana were greatly improved. When dealt with salt and cold treatments, compared with wild-type and unloaded line (UL) A. thaliana, the transgenic lines had higher contents of proline and chlorophyll, as well as higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the transgenic A. thaliana had lower level of malondialdehyde (MDA) and electrolytic leakage (EL) than wild-type and UL A. thaliana under salt and cold stress. Meanwhile, FvMYB82 can also regulate the expression of downstream genes associated with salt stress (AtSnRK2.4, AtSnRK2.6, AtKUP6, and AtNCED3) and cold stress (AtCBF1, AtCBF2, AtCOR15a, and AtCOR78). Therefore, these results indicated that FvMYB82 probably plays an important role in the response to salt and cold stresses in A. thaliana by regulating downstream related genes.

Plants are often exposed to biotic or abiotic stress, which can seriously impede their growth and development. In recent years, researchers have focused especially on the study of plant responses to biotic and abiotic stress. As one of the most widely planted grapevine rootstocks, ‘Beta’ has been extensively proven to be highly resistant to stress. However, further research is needed to understand the mechanisms of abiotic stress in ‘Beta’ rootstocks. In this study, we isolated and cloned a novel WRKY transcription factor, VhWRKY44, from the ‘Beta’ rootstock. Subcellular localization analysis revealed that VhWRKY44 was a nuclear-localized protein. Tissue-specific expression analysis indicated that VhWRKY44 had higher expression levels in grape roots and mature leaves. Further research demonstrated that the expression level of VhWRKY44 in grape roots and mature leaves was highly induced by salt and cold treatment. Compared with the control, Arabidopsis plants overexpressing VhWRKY44 showed stronger resistance to salt and cold stress. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were significantly increased, and the contents of proline, malondialdehyde (MDA) and chlorophyll were changed considerably. In addition, significantly higher levels of stress-related genes were detected in the transgenic lines. The results indicated that VhWRKY44 was an important transcription factor in ‘Beta’ with excellent salt and cold tolerance, providing a new foundation for abiotic stress research.

In viticulture, the highly resistant rootstock ‘Beta’ is widely used in Chinese grape production to avoid the effects of soil salinization and drought on grape growth. However, the mechanism of high resistance to abiotic stress in the ‘Beta’ rootstock is not clear. In this study, we demonstrated that VhMYB2 as a transcription factor made a significant contribution to salinity and drought stress, which was isolated from the ‘Beta’ rootstock. The coding sequence of the VhMYB2 gene was 858 bp, encoding 285 amino acids. The subcellular localization of VhMYB2 was located in the nucleus of tobacco epidermal cells. Moreover, RT-qPCR found that VhMYB2 was predominantly expressed in the mature leaf and root of the grape. Under salinity and drought stress, overexpressing VhMYB2 showed a higher resistant phenotype and survival rates in A. thaliana while the transgenic lines had a survival advantage by measuring the contents of proline, chlorophyll, and MDA, and activities of POD, SOD, and CAT, and expression levels of related stress response genes. The results reveal that VhMYB2 may be an important transcription factor regulating ‘Beta’ resistance in response to abiotic stress.

MYB (v-MYB avian myeloblastosis viral oncogene homolog) transcription factor (TF) family has numerous members with complex and diverse functions, which perform an integral role in regulating the plant’s response to adversity. This study used cloning to obtain a novel MYB TF gene from the diploid strawberry Fragaria vesca, which was given the designation FvMYB44. Subcellular localization results showed that the protein of FvMYB44 was a nuclear localization protein. The resistance of Arabidopsis thaliana to salt and low temperature stresses was greatly enhanced by the overexpression of FvMYB44. When subjected to salt and temperature stress, transgenic plants showed higher proline and chlorophyll concentrations and higher superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities than wild-type (WT) and unloaded line (UL) of A. thaliana. In contrast, WT and UL lines had higher malondialdehyde (MDA) content and reactive oxygen species ROS (O₂⁻ and H₂O₂) content. These findings suggest that FvMYB44 may perform a role in controlling the response of A. thaliana to cold and salt stress.

The NAC (NAM, ATAF1/2, CUC2) family of transcription factors (TFs) is a vital transcription factor family of plants. It controls multiple parts of plant development, tissue formation, and abiotic stress response. We cloned the FvNAC29 gene from Fragaria vesca (a diploid strawberry) for this research. There is a conserved NAM structural domain in the FvNAC29 protein. The highest homology between FvNAC29 and PaNAC1 was found by phylogenetic tree analysis. Subcellular localization revealed that FvNAC29 is localized onto the nucleus. Compared to other tissues, the expression level of FvNAC29 was higher in young leaves and roots. In addition, Arabidopsis plants overexpressing FvNAC29 had higher cold and high-salinity tolerance than the wild type (WT) and unloaded line with empty vector (UL). The proline and chlorophyll contents of transgenic Arabidopsis plants, along with the activities of the antioxidant enzymes like catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) under 200 mM NaCl treatment or −8 °C treatment, were higher than those activities of the control. Meanwhile, malondialdehyde (MDA) and the reactive oxygen species (ROS) content were higher in the WT and UL lines. FvNAC29 improves transgenic plant resistance to cold and salt stress by regulating the expression levels of AtRD29a, AtCCA1, AtP5CS1, and AtSnRK2.4. It also improves the potential to tolerate cold stress by positively regulating the expression levels of AtCBF1, AtCBF4, AtCOR15a, and AtCOR47. These findings suggest that FvNAC29 may be related to the processes and the molecular mechanisms of F. vesca response to high-salinity stress and LT stress, providing a comprehensive understanding of the NAC TFs.