Decrypting the Mechanism of Protein Transcription in Plant Stress Resistance

The ERF gene family is widely present in plants and has crucial regulatory importance in plant seed development, organ morphogenesis, the synthesis of secondary metabolites, and coping with abiotic stresses such as cold and drought. In this study, 90 members of CsERF were screened by bioinformatics tools analysis and named CsERF1–CsERF90. Their molecular characteristics and systematic evolution were studied, and the tissue expression characteristics of CSERF genes and the composition of promoter cis-acting elements were predicted. The results showed that 81 proteins encoded by CsERF genes had conserved motifs 1, 2, and 3, while 64 members possessed other motifs. The theoretical isoelectric point was between 4.49 and 10.24, and 85 members constituted unstable proteins, while the rest were stable proteins. Subcellular localization predicted that 77 members were in the nucleus, 8 were in the chloroplasts, and 5 were in the mitochondria. The promoter sequence of CsERFs was found to include not only cis-acting elements related to hormone regulation, such as gibberellin (41), methyl jasmonate (110), and abscisic acid (185), but also cis-acting elements involved in low-temperature response (56) and light response (22), indicating that CsERFs have a key role in plant growth and abiotic stress. Phylogenetic analysis of tea plant and Arabidopsis thaliana ERF gene families showed that the tea plant ERF gene families could be divided into six groups, with B3 having 29 members at most and B1 having only 3 members at least. The phylogenetic tree constructed using only the CsERF genes is also divided into six groups, with slightly different but minimal differences in members. Of the 90 tea plant ERF members, 85 were located on 15 chromosomes, whereas 5 were not located on chromosomes. The collinearity analysis showed that there were 41 homologous gene pairs among the CsERFs, and these homologous gene pairs may have the same function. According to the expression of CsERFs in cold-stressed tea plant and in different tissues, 90 CsERF genes played their respective roles in different tissues and stages to regulate plant growth, and some of them participated in the process of cold stress tolerance. This study provides a theoretical foundation for the study of tea plant growth and development and low-temperature resistance. Full article

At present, there are many excellent cultivars of raspberry worldwide with different fruit colors, such as yellow, red, purple and black. Anthocyanin accumulation is responsible for flower and fruit coloration in plants. Anthocyanins belong to flavonoids which are natural pigments widely distributed in plants. The MYB transcription factor (TF) plays a vital regulatory role in the metabolic pathway of anthocyanins. Here, RoMYB10, an R2R3-MYB in black raspberry (Rubus occidentalis L.), was isolated. The basic physical and chemical properties, conserved motif distribution, evolutionary relationship and subcellular localization were analyzed for the RoMYB10 encoded amino acid sequence. The contents of anthocyanin were determined in four different colored raspberry fruits by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS). The expression levels of MYB10 genes in various tissues and fruits at different developmental stages of the four different colored raspberries were detected by real-time fluorescence quantitative PCR (qRT-PCR). The results showed that the contents of anthocyanin and the expression levels of the MYB10 gene were the highest in black raspberry. Moreover, the expression of MYB10 in the fruit was significantly higher than in other tissues, especially in ripe and mottled fruits. When ectopic overexpression of RoMYB10 occurred in tobacco, the expression levels of the RoMYB10 gene and total anthocyanin contents in transgenic tobacco plants were significantly higher than those in wild-type (WT) plants. In addition, overexpression of RoMYB10 up-regulated the key genes in the anthocyanin biosynthesis, such as NtCHS, NtCHI, NtF3H, NtANS and NtUFGT. Our study suggests that RoMYB10 is involved in the regulating of anthocyanin biosynthesis in raspberry and has potential as a molecular tool for manipulating biosynthesis of anthocyanins in fruits using metabolic engineering. Full article

As an excellent grafting material, Malus baccata (L.) Borkh is native to Liaoning, Jilin, Heilongjiang and other regions in China, with a strong adverse environmental adaptability. As a typical transcription factor, the NAC gene acts as a regulator in many molecular pathways responding to abiotic stress. However, research of NAC in the Malus baccata has just begun. In the present research, a new NAC transcription factor, MbNAC22, was obtained from the seedlings of Malus baccata, and its function in drought and salt treatments was studied by heterologous expression. The open reading frame of the MbNAC22 gene is 768, encoding 255 amino acids (aa). Through confocal microscopy, MbNAC22 was found to be located in the nucleus. The heterologous expression of MbNAC22 in Arabidopsis showed that it enhanced the viability of Arabidopsis under drought and salt treatments. Under stresses, the chlorophyll content of the plants decreased, but the decline of the overexpressed-MbNAC22 Arabidopsis was relatively low. Through phenotypic observation and determination of stress-related physiological indicators, it was found that compared with WT Arabidopsis, overexpressed-MbNAC22 Arabidopsis had a higher tolerance to stresses. Under stresses, the overexpression of MbNAC22 positively regulated ion-transport-related genes (AtNHX1 and AtSOS1), the key genes of the ABA pathway (AtNCED3 and AtDREB2A), the proline synthesis gene (AtP5CS2) and the drought-induced gene (AtERD11), while the expression of the leaf senescence-associated gene (AtSAG21) and programmed cell death related gene (AtAEP1) was inhibited. Therefore, we speculate that MbNAC22 responds positively to drought and salt stresses by regulating the expression of stress-related genes. Full article

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. Full article

Melatonin (MT), a naturally occurring compound, is found in various species worldwide. In 1958, it was first identified in the pineal gland of dairy cows. MT is an “old friend” but a “new compound” for plant biology. It brings experts and research minds from the broad field of plant sciences due to its considerable influence on plant systems. The MT production process in plants and animals is distinct, where it has been expressed explicitly in chloroplasts and mitochondria in plants. Tryptophan acts as the precursor for the formation of phyto-melatonin, along with intermediates including tryptamine, serotonin, N-acetyl serotonin, and 5-methoxy tryptamine. It plays a vital role in growth phases such as the seed germination and seedling growth of crop plants. MT significantly impacts the gas exchange, thereby improving physio-chemical functions in plant systems. During stress, the excessive generation and accumulation of reactive oxygen species (ROS) causes protein oxidation, lipid peroxidation, nucleic acid damage, and enzyme inhibition. Because it directly acts as an antioxidant compound, it awakens the plant antioxidant defense system during stress and reduces the production of ROS, which results in decreasing cellular oxidative damage. MT can enhance plant growth and development in response to various abiotic stresses such as drought, salinity, high temperature, flooding, and heavy metals by regulating the antioxidant mechanism of plants. However, these reactions differ significantly from crop to crop and are based on the level and kind of stress. The role of MT in the physiological functions of plants towards plant growth and development, tolerance towards various abiotic stresses, and approaches for enhancing the endogenous MT in plant systems are broadly reviewed and it is suggested that MT is a steering compound in directing major physiological functions of plants under the changing climate in future. Full article