Potato miR394 targets StA/N-INVE and StLCR to negatively regulate late blight resistance.

MicroRNAs (miRNAs) are small noncoding RNAs in eukaryotes. Plant endogenous miRNAs play pivotal roles in regulating plant development and defense responses. MicroRNA394 (miR394) has been reported to regulate plant development, abiotic stresses and defense responses. Previous reports showed that miR394 responded to P. infestans inoculation in potato, indicating that miR394 may be involved in defense responses. In this study, we further investigated its role in potato defense against P. infestans. Stable expression of miR394 in tobacco and potato enhances the susceptibility to P. infestans, which is accompanied with the reduced accumulation of ROS and down-regulation of the PTI (pattern-triggered immunity) marker genes. Besides well-known target StLCR, miR394 also targets StA/N-INVE, which encodes a chloroplast Alkaline/Neutral Invertases (A/N-INVE). Both StLCR and StA/N-INVE positively regulate late blight resistance, while miR394 degrades them. Interestingly, StA/N-INVE is located in the chloroplast, indicating that miR394 may manipulate chloroplast immunity. Degradation of StA/N-INVE may affect the chloroplast function and hence lead to the compromised ROS (reactive oxygen species) burst and reduced retrograde signaling from the chloroplast to the nucleus and cytoplasm. In summary, this study provides new information that miR394 targets and degrades StA/N-INVE and StLCR, which are positive regulators, to enhance potato susceptibility to P. infestans.

Circadian rhythm response and its effect on photosynthetic characteristics of the Lhcb family genes in tea plant.

BACKGROUND: The circadian clock, also known as the circadian rhythm, is responsible for predicting daily and seasonal changes in the environment, and adjusting various physiological and developmental processes to the appropriate times during plant growth and development. The circadian clock controls the expression of the Lhcb gene, which encodes the chlorophyll a/b binding protein. However, the roles of the Lhcb gene in tea plant remain unclear. RESULTS: In this study, a total of 16 CsLhcb genes were identified based on the tea plant genome, which were distributed on 8 chromosomes of the tea plant. The promoter regions of CsLhcb genes have a variety of cis-acting elements including hormonal, abiotic stress responses and light response elements. The CsLhcb family genes are involved in the light response process in tea plant. The photosynthetic parameter of tea leaves showed rhythmic changes during the two photoperiod periods (48 h). Stomata are basically open during the day and closed at night. Real-time quantitative PCR results showed that most of the CsLhcb family genes were highly expressed during the day, but were less expressed at night. CONCLUSIONS: Results indicated that CsLhcb genes were involved in the circadian clock process of tea plant, it also provided potential references for further understanding of the function of CsLhcb gene family in tea plant.

[Cloning and expression pattern analysis of abscisic acid receptor gene McPYL4 in Mentha canadensis].

Mentha canadensis is a traditional Chinese herb with great medicinal and economic value. Abscisic acid(ABA) receptor PYLs have important roles in plant growth and development and response to adversity. The M. canadensis McPYL4 gene was cloned, and its protein characteristics, gene expression, and protein interactions were analyzed, so as to provide genetic resources for genetic improvement and molecular design breeding for M. canadensis resistance. Therefore, the protein characteristics, subcellular localization, gene expression pattern, and protein interactions of McPYL4 were analyzed by bioinformatics analysis, transient expression of tobacco leaves, RT-qPCR, and yeast two-hybrid(Y2H) techniques. The results showed that the McPYL4 gene was 621 bp in length, encoding 206 amino acids, and its protein had the conserved structural domain of SRPBCC and was highly homologous with Salvia miltiorrhiza SmPYL4. McPYL4 protein was localized to the cell membrane and nucleus. The McPYL4 gene was expressed in all tissue of M. canadensis, with the highest expression in roots, followed by leaves, and it showed a pattern of up-regulation followed by down-regulation in leaves 1-8. In both leaves and roots, the McPYL4 gene responded to the exogenous hormones ABA, MeJA, and the treatments of drought, AlCl_3, NaCl, CdCl_2, and CuCl_2. Moreover, McPYL4 was up-regulated for expression in both leaves and roots under the MeJA treatment, as well as in leaves treated with AlCl_3 stress for 1 h, whereas McPYL4 showed a tendency to be down-regulated in both leaves and roots under other treatments. Protein interactions showed that McPYL4 interacted with AtABI proteins in an ABA-independent manner. This study demonstrated that McPYL4 responded to ABA, JA, and several abiotic stress treatments, and McPYL4 was involved in ABA signaling in M. canadensis and thus in the regulation of leaf development and various abiotic stresses in M. canadensis.

Characteristics of NAC transcription factors in Solanaceae crops and their roles in responding to abiotic and biotic stresses.

As one of the largest transcription factor (TF) families in plants, the NAC (NAM, ATAF1/2, and CUC2) family plays important roles in response pathways to various abiotic and biotic stresses, such as drought, high salinity, low temperature, and pathogen infection. Although, there are a number of reviews on the involvement of NAC TF in plant responses to biotic and abiotic stresses, most of them are focused on the model plants Arabidopsis thaliana and Oryza sativa, and there is a lack of systematic evaluation of specific species. Solanaceae, the world's third most significant cash crop, has been seriously affected by environmental disturbances in recent years in terms of yield and quality, posing a severe threat to global food security. This review focuses on the functional roles of NAC transcription factors in response to external stresses involved in five important Solanaceae crops: tomato, potato, pepper, eggplant and tobacco, and analyzes the affinities between them. It will provide resources for stress-resistant breeding of Solanaceae crops using transgenic technology.

Genome-wide identification, subcellular localization, and expression analysis of the phosphatidyl ethanolamine-binding protein family reveals the candidates involved in flowering and yield regulation of Tartary buckwheat (Fagopyrum tataricum).

Background: PEBP (phosphatidyl ethanolamine-binding protein) is widely found in eukaryotes including plants, animals and microorganisms. In plants, the PEBP family plays vital roles in regulating flowering time and morphogenesis and is highly associated to agronomic traits and yields of crops, which has been identified and characterized in many plant species but not well studied in Tartary buckwheat (Fagopyrum tataricum Gaertn.), an important coarse food grain with medicinal value. Methods: Genome-wide analysis of FtPEBP gene family members in Tartary buckwheat was performed using bioinformatic tools. Subcellular localization analysis was performed by confocal microscopy. The expression levels of these genes in leaf and inflorescence samples were analyzed using qRT-PCR. Results: Fourteen Fagopyrum tataricum PEBP (FtPEBP) genes were identified and divided into three sub-clades according to their phylogenetic relationships. Subcellular localization analysis of the FtPEBP proteins in tobacco leaves indicated that FT- and TFL-GFP fusion proteins were localized in both the nucleus and cytoplasm. Gene structure analysis showed that most FtPEBP genes contain four exons and three introns. FtPEBP genes are unevenly distributed in Tartary buckwheat chromosomes. Three tandem repeats were found among FtFT5/FtFT6, FtMFT1/FtMFT2 and FtTFL4/FtTFL5. Five orthologous gene pairs were detected between F. tataricum and F. esculentum. Seven light-responsive, nine hormone-related and four stress-responsive elements were detected in FtPEBPs promoters. We used real-time PCR to investigate the expression levels of FtPEBPs among two flowering-type cultivars at floral transition time. We found FtFT1/FtFT3 were highly expressed in leaf and young inflorescence of early-flowering type, whereas they were expressed at very low levels in late-flowering type cultivars. Thus, we deduced that FtFT1/FtFT3 may be positive regulators for flowering and yield of Tartary buckwheat. These results lay an important foundation for further studies on the functions of FtPEBP genes which may be utilized for yield improvement.

Genome-wide identification of tea plant (Camellia sinensis) BAHD acyltransferases reveals their role in response to herbivorous pests.

BACKGROUND: BAHD acyltransferases are among the largest metabolic protein domain families in the genomes of terrestrial plants and play important roles in plant growth and development, aroma formation, and biotic and abiotic stress responses. Little is known about the BAHDs in the tea plant, a cash crop rich in secondary metabolites. RESULTS: In this study, 112 BAHD genes (CsBAHD01-CsBAHD112) were identified from the tea plant genome, with 85% (98/112) unevenly distributed across the 15 chromosomes. The number of BAHD gene family members has significantly expanded from wild tea plants to the assamica type to the sinensis type. Phylogenetic analysis showed that they could be classified into seven subgroups. Promoter cis-acting element analysis revealed that they contain a large number of light, phytohormones, and stress-responsive elements. Many members displayed tissue-specific expression patterns. CsBAHD05 was expressed at more than 500-fold higher levels in purple tea leaves than in green tea leaves. The genes exhibiting the most significant response to MeJA treatment and feeding by herbivorous pests were primarily concentrated in subgroups 5 and 6. The expression of 23 members of these two subgroups at different time points after feeding by tea green leafhoppers and tea geometrids was examined via qPCR, and the results revealed that the expression of CsBAHD93, CsBAHD94 and CsBAHD95 was significantly induced after the tea plants were subjected to feeding by both pricking and chewing pests. Moreover, based on the transcriptome data for tea plants being fed on by these two pests, a transcriptional regulatory network of different transcription factor genes coexpressed with these 23 members was constructed. CONCLUSIONS: Our study provides new insights into the role of BAHDs in the defense response of tea plants, and will facilitate in-depth studies of the molecular function of BAHDs in resistance to herbivorous pests.

[Cloning and functional analysis of AcFMO from onion during alliine biosynthesis].

Flavin-containing monooxygenase (FMO) is the key enzyme in the biosynthesis pathway of CSOs with sulfur oxidation. In order to explore the molecular regulatory mechanism of FMO in the synthesis of onion CSOs, based on transcriptome database and phylogenetic analysis, one AcFMO gene that may be involved in alliin synthesis was obtained, the AcFMO had a cDNA of 1 374 bp and encoded 457 amino acids, which was evolutionarily closest to the AsFMO of garlic. Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) indicated that AcFMO was the highest in the flowers and the lowest in the leaf sheaths. The results of subcellular localization showed that the AcFMO gene product was widely distributed throughout the cell A yeast expression vector was constructed, and the AcFMO gene was ecotopically overexpressed in yeast to further study the enzyme function in vitro and could catalyze the synthesis of alliin by S-allyl-l-cysteine. In summary, the cloning and functional identification of AcFMO have important reference value for understanding the biosynthesis of CSOs in onions.

Integrated transcriptome and metabolome analysis provide insights into the mechanism of saponin biosynthesis and its role in alleviating cadmium-induced oxidative damage in Ophiopogon japonicum.

Zhe-Maidong, a cultivar of Ophiopogon japonicus is a prominent traditional herbal medicine rich in saponins. This study explored the mechanism of saponin biosynthesis and its role in alleviating Cd-induced oxidative damage in the Zhe-Maidong cultivar using three experimental groups undergoing Cd stress. In the Cd-contaminated soil treatment, total saponins were 1.68 times higher than those in the control. The saponin content in the Cd-2 and Cd-3 treatments was approximately twice as high as that in the Cd-CK treatment. These findings revealed that Cd stress leads to total saponin accumulation. Metabolomic analysis identified the accumulated saponins, primarily several monoterpenoids, diterpenoids, and triterpenoids. The increased saponins exhibited an antioxidant ability to prevent the accumulation of Cd-induced reactive oxygen species (ROS). Subsequent saponin application experiments provided strong evidence that saponin played a crucial role in promoting superoxide dismutase (SOD) activity and reducing ROS accumulation. Transcriptome analysis revealed vital genes for saponin synthesis under Cd stress, including SE, two SSs, and six CYP450s, positively correlated with differentially expressed metabolite (DEM) levels in the saponin metabolic pathway. Additionally, the TF-gene regulatory network demonstrated that bHLH1, bHLH3, mTERF, and AUX/IAA transcript factors are crucial regulators of hub genes involved in saponin synthesis. These findings significantly contribute to our understanding of the regulatory network of saponin synthesis and its role in reducing oxidative damage in O. japonicum when exposed to Cd stress.

A novel bHLH gene responsive to low nitrogen positively regulates the biosynthesis of medicinal tropane alkaloids in Atropa belladonna.

Medicinal tropane alkaloids (TAs), including hyoscyamine, anisodamine and scopolamine, are essential anticholinergic drugs specifically produced in several solanaceous plants. Atropa belladonna is one of the most important medicinal plants that produces TAs. Therefore, it is necessary to cultivate new A. belladonna germplasm with the high content of TAs. Here, we found that the levels of TAs were elevated under low nitrogen (LN) condition, and identified a LN-responsive bHLH transcription factor (TF) of A. belladonna (named LNIR) regulating the biosynthesis of TAs. The expression level of LNIR was highest in secondary roots where TAs are synthesized specifically, and was significantly induced by LN. Further research revealed that LNIR directly activated the transcription of hyoscyamine 6ß-hydroxylase gene (H6H) by binding to its promoter, which converts hyoscyamine into anisodamine and subsequently epoxidizes anisodamine to form scopolamine. Overexpression of LNIR upregulated the expression levels of TA biosynthesis genes and consequently led to the increased production of TAs. In summary, we functionally identified a LN-responsive bHLH gene that facilitated the development of A. belladonna with high-yield TAs under the decreased usage of nitrogen fertilizer.

Gene expression analysis of potato drought-responsive genes under drought stress in potato (Solanum tuberosum L.) cultivars.

The potato (Solanum tuberosum L.), an important field crop consumed extensively worldwide, is adversely affected by abiotic stress factors especially drought. Therefore, it is vital to understand the genetic mechanism under drought stress to decrease loose of yield and quality . This trial aimed to screen drought-responsive gene expressions of potato and determine the drought-tolerant potato cultivar. The trial pattern is a completely randomized block design (CRBD) with four replications under greenhouse conditions. Four cultivars (Brooke, Orwell, Vr808, Shc909) were irrigated with four different water regimes (control and three stress conditions), and the gene expression levels of 10 potato genes were investigated. The stress treatments as follows: Control = 100% field capacity; slight drought = 75% field capacity; moderate drought = 50% field capacity, and severe drought 25% field capacity. To understand the gene expression under drought stress in potato genotypes, RT-qPCR analysis was performed and results showed that the genes most associated with drought tolerance were the StRD22 gene, MYB domain transcription factor, StERD7, Sucrose Synthase (SuSy), ABC Transporter, and StDHN1. The StHSP100 gene had the lowest genetic expression in all cultivars. Among the cultivars, the Orwell exhibited the highest expression of the StRD22 gene under drought stress. Overall, the cultivar with the highest gene expression was the Vr808, closely followed by the Brooke cultivar. As a result, it was determined that potato cultivars Orwell, Vr808, and Brooke could be used as parents in breeding programs to develop drought tolerant potato cultivars.

Genome-Wide Identification of LOX Gene Family and Its Expression Analysis under Abiotic Stress in Potato (Solanum tuberosum L.).

The lipoxygenases (LOXs) are non-heme iron-containing dioxygenases that play an important role in plant growth and defense responses. There is scarce knowledge regarding the LOX gene family members and their involvement in biotic and abiotic stresses in potato. In this study, a total of 17 gene family members (StLOXs) in potato were identified and clustered into three subfamilies: 9-LOX type I, 13-LOX type I, and 13-LOX type II, with eleven, one, and five members in each subfamily based on phylogenetic analysis. By exploiting the RNA-seq data in the Potato Genome Sequencing Consortium (PGSC) database, the tissue-specific expressed and stress-responsive StLOX genes in double-monoploid (DM) potato were obtained. Furthermore, six candidate StLOX genes that might participate in drought and salt response were determined via qPCR analysis in tetraploid potato cultivars under NaCl and PEG treatment. Finally, the involvement in salt stress response of two StLOX genes, which were significantly up-regulated in both DM and tetraploid potato under NaCl and PEG treatment, was confirmed via heterologous expression in yeast under salt treatment. Our comprehensive analysis of the StLOX family provides a theoretical basis for the potential biological functions of StLOXs in the adaptation mechanisms of potato to stress conditions.

DNA-Binding with One Finger (Dof) Transcription Factor Gene Family Study Reveals Differential Stress-Responsive Transcription Factors in Contrasting Drought Tolerance Potato Species.

DNA-binding with one finger (Dof) proteins comprise a large family that play central roles in stress tolerance by regulating the expression of stress-responsive genes via the DOFCORE element or by interacting with other regulatory proteins. Although the Dof TF has been identified in a variety of species, its systemic analysis in potato (Solanum tuberosum L.) is lacking and its potential role in abiotic stress responses remains unclear. A total of 36 potential Dof genes in potato were examined at the genomic and transcriptomic levels in this work. Five phylogenetic groups can be formed from these 36 Dof proteins. An analysis of cis-acting elements revealed the potential roles of Dofs in potato development, including under numerous abiotic stress conditions. The cycling Dof factors (CDFs) might be the initial step in the abiotic stress response signaling cascade. In potato, five CDFs (StCDF1/StDof19, StCDF2/StDof4, StCDF3/StDof11, StCDF4/StDof24, and StCDF5/StDof15) were identified, which are homologs of Arabidopsis CDFs. The results revealed that these genes were engaged in a variety of abiotic reactions. Moreover, an expression analysis of StDof genes in two potato cultivars ('Long10' (drought tolerant) and 'DXY' (drought susceptible)) of contrasting tolerances under drought stress was carried out. Further, a regulatory network mediated by lncRNA and its target Dofs was established. The present study provides fundamental knowledge for further investigation of the roles of Dofs in the adaptation of potato to drought stress, aiming to provide insights into a viable strategy for crop improvement and stress-resistance breeding.

Alternative splicing of CsWRKY21 positively regulates cold response in tea plant.

Alternative splicing (AS) was an important post-transcriptional mechanism that involved in plant resistance to adversity stress. WRKY transcription factors function as transcriptional activators or repressors to modulate plant growth, development and stress response. However, the role of alternate splicing of WRKY in cold tolerance is poorly understood in tea plants. In this study, we found that the CsWRKY21 transcription factor, a member of the WRKY IId subfamily, was induced by low temperature. Subcellular localization and transcriptional activity assays showed that CsWRKY21 localized to the nucleus and had no transcriptional activation activity. Y1H and dual-luciferase reporter assays showed that CsWRKY21 suppressed expression of CsABA8H and CsUGT by binding with their promoters. Transient overexpression of CsABA8H and CsUGT reduced abscisic acid (ABA) content in tobacco leaves. Furthermore, we discovered that CsWRKY21 undergoes AS in the 5'UTR region. The AS transcript CsWRKY21-b was induced at low temperature, up to 6 folds compared to the control, while the full-length CsWRKY21-a transcript did not significantly change. Western blot analysis showed that the retention of introns in the 5'UTR region of CsWRKY21-b led to higher CsWRKY21 protein content. These results revealed that alternative splicing of CsWRKY21 involved in cold tolerance of tea plant by regulating the protein expression level and then regulating the content of ABA, and provide insights into molecular mechanisms of low temperature defense mediated by AS in tea plant.

Exo84c-regulated degradation is involved in the normal self-incompatible response in Brassicaceae.

The self-incompatibility system evolves in angiosperms to promote cross-pollination by rejecting self-pollination. Here, we show the involvement of Exo84c in the SI response of both Brassica napus and Arabidopsis. The expression of Exo84c is specifically elevated in stigma during the SI response. Knocking out Exo84c in B. napus and SI Arabidopsis partially breaks down the SI response. The SI response inhibits both the protein secretion in papillae and the recruitment of the exocyst complex to the pollen-pistil contact sites. Interestingly, these processes can be partially restored in exo84c SI Arabidopsis. After incompatible pollination, the turnover of the exocyst-labeled compartment is enhanced in papillae. However, this process is perturbed in exo84c SI Arabidopsis. Taken together, our results suggest that Exo84c regulates the exocyst complex vacuolar degradation during the SI response. This process is likely independent of the known SI pathway in Brassicaceae to secure the SI response.

Acyl-CoA synthetase 1 plays an important role on pollen development and male fertility in tomato.

The development of pollen is critical to male reproduction in flowering plants. Acyl-CoA synthetase (ACOS) genes play conserved functions in regulating pollen development in various plants. Our previous work found that knockout of the SlACOS1 gene in tomato might decrease fruit setting. The current study further revealed that SlACOS1 was important to pollen development and male fertility. The SlACOS1 gene was preferentially expressed in the stamen of the flower with the highest expression at the tetrad stage of anther development. Mutation of the SlACOS1 gene by the CRISPR/Cas9-editing system reduced pollen number and viability as well as fruit setting. The tapetum layer exhibited premature degradation and the pollen showed abnormal development appearing irregular, shriveled, or anucleate in Slacos1 mutants at the tetrad stage. The fatty acid metabolism in anthers was significantly impacted by mutation of the SlACOS1 gene. Furthermore, targeted fatty acids profiling using GC-MS found that contents of most fatty acids except C18:1 and C18:2 were reduced. Yeast complementation assay demonstrated that the substrate preferences of SlACOS1 were C16:0 and C18:0 fatty acids. Male fertility of Slacos1 mutant could be slightly restored by applying exogenous palmitic acid, a type of C16:0 fatty acid. Taken together, SlACOS1 played important roles on pollen development and male fertility by regulating the fatty acid metabolism and the development of tapetum and tetrad. Our findings will facilitate unraveling the mechanism of pollen development and male fertility in tomato.

CsREV-CsTCP4-CsVND7 module shapes xylem patterns differentially between stem and leaf to enhance tea plant tolerance to drought.

Cultivating drought-tolerant tea varieties enhances both yield and quality of tea plants in northern China. However, the mechanisms underlying their drought tolerance remain largely unknown. Here we identified a key regulator called CsREV, which differentially regulates xylem patterns between leaves and stems, thereby conferring drought tolerance in tea plants. When drought occurs, upregulation of CsREV activates the CsVND7a-dependent xylem vessel differentiation. However, when drought persists, the vessel differentiation is hindered as CsVND7a is downregulated by CsTCP4a. This, combined with the CsREV-promoted secondary-cell-wall thickness of xylem vessel, leads to the enhanced curling of leaves, a characteristic closely associated with plant drought tolerance. Notably, this inhibitory effect of CsTCP4a on CsVND7a expression is absent in stems, allowing stem xylem vessels to continuously differentiate. Overall, the CsREV-CsTCP4-CsVND7 module is differentially utilized to shape the xylem patterns in leaves and stems, potentially balancing water transportation and utilization to improve tea plant drought tolerance.

The miR166 targets CsHDZ3 genes to negatively regulate drought tolerance in tea plant (Camellia sinensis).

Drought is the stressor with a significant adverse impact on the yield stability of tea plants. HD-ZIP III transcription factors (TFs) play important regulatory roles in plant growth, development, and stress responses. However, whether and how HD-ZIP III TFs are involved in drought response and tolerance in tea plants remains unclear. Here, we identified seven HD-ZIP III genes (CsHDZ3-1 to CsHDZ3-7) in tea plant genome. The evolutionary analysis demonstrated that CsHDZ3 members were subjected to purify selection. Subcellular localization analysis revealed that all seven CsHDZ3s located in the nucleus. Yeast self-activation and dual-luciferase reporter assays demonstrated that CsHDZ3-1 to CsHDZ3-4 have trans-activation ability whereas CsHDZ3-5 to CsHDZ3-7 served as transcriptional inhibitors. The qRT-PCR assay showed that all seven CsHDZ3 genes could respond to simulated natural drought stress and polyethylene glycol treatment. Further assays verified that all CsHDZ3 genes can be cleaved by csn-miR166. Overexpression of csn-miR166 inhibited the expression of seven CsHDZ3 genes and weakened drought tolerance of tea leaves. In contrast, suppression of csn-miR166 promoted the expression of seven CsHDZ3 genes and enhanced drought tolerance of tea leaves. These findings established the foundation for further understanding the mechanism of CsHDZ3-miR166 modules' participation in drought responses and tolerance.

Genome-wide analyses of the GbAP2 subfamily reveal the function of GbTOE1a in salt and drought stress tolerance in Ginkgo biloba.

The APETALA2 (AP2) transcription factors play crucial roles in plant growth and stage transition. Ginkgo biloba is an important medicinal plant renowned for the rich flavonoid content in its leaves. In this study, 18 GbAP2s were identified from the G. biloba genome and classified into three clusters. We found that the members of the euAP2 cluster, including four TOEs (GbTOE1a/1b/1c/3), exhibited a higher expression level in most samples compared to other members. Specifically, GbTOE1a may have a positive regulatory role in salt and drought stress responses. The overexpression of GbTOE1a in G. biloba calli resulted in a significant increase in the flavonoid content and upregulation of flavonoid biosynthesis genes, including PAL, 4CL, CHS, F3H, FLSs, F3'Hs, OMT, and DFRs. By contrast, the silencing of GbTOE1a in seedlings decreased the flavonoid content and the expression of flavonoid synthesizing genes. In addition, the silenced seedlings exhibited decreased antioxidant levels and a higher sensitivity to salt and drought treatments, suggesting a crucial role of GbTOE1a in G. biloba salt and drought tolerance. To the best of our knowledge, this was the first investigation into the identification and characterization of GbAP2s in G. biloba. Our results lay a foundation for further research on the regulatory role of the AP2 family in flavonoid synthesis and stress responses.

StoMYB41 positively regulates the Solanum torvum response to Verticillium dahliae in an ABA dependent manner.

MYB transcription factor despite their solid involvement in growth are potent regulator of plant stress response. Herein, we identified a MYB gene named as StoMYB41 in a wild eggplant species Solanum torvum. The expression level of StoMYB41 was higher in root than the tissues including stem, leaf, and seed. It induced significantly by Verticillium dahliae inoculation. StoMYB41 was localized in the nucleus and exhibited transcriptional activation activity. Silencing of StoMYB41 enhanced susceptibility of Solanum torvum against Verticillium dahliae, accompanied by higher disease index. The significant down-regulation of resistance marker gene StoABR1 comparing to the control plants was recorded in the silenced plants. Moreover, transient expression of StoMYB41 could trigger intense hypersensitive reaction mimic cell death, darker DAB and trypan blue staining, higher ion leakage, and induced the expression levels of StoABR1 and NbDEF1 in the leaves of Solanum torvum and Nicotiana benthamiana. Taken together, our data indicate that StoMYB41 acts as a positive regulator in Solanum torvum against Verticillium wilt.

Genome-wide characterization and function analysis of ginger (Zingiber officinale Roscoe) ZoGRFs in responding to adverse stresses.

Growth-regulating factors (GRFs) play crucial roles in plant growth, development, hormone signaling, and stress response. Despite their significance, the roles of GRFs in ginger remain largely unknown. Herein, 31 ginger ZoGRFs were identified and designated as ZoGRF1-ZoGRF31 according to their phylogenetic relationships. All ZoGRFs were characterized as unstable, hydrophilic proteins, with 29 predicted to be located in the nucleus. Functional cis-elements related to growth and development were enriched in ZoGRF's promoter regions. RNA-seq and RT-qPCR analysis revealed that ZoGRF12, ZoGRF24, and ZoGRF28 were highly induced in various growth and development stages, displaying differential regulation under waterlogging, chilling, drought, and salt stresses, indicating diverse expression patterns of ZoGRFs. Transient expression analysis in Nicotiana benthamiana indicated that overexpressing ZoGRF28 regulated the transcription levels of salicylic acid, jasmonic acid, and pattern-triggered immunity-related genes, increased chlorophyll content and contributed to reduced disease lesions and an increased net photosynthetic rate. This research lays the foundation for further understanding the biological roles of ZoGRFs.