Plant Growth Responses Research Articles

Genome-wide identification, characterization and expression pattern analysis of TIFY family members in Artemisia argyi

BackgroundPlant-specific TIFY proteins play crucial roles in regulating plant growth, development, and various stress responses. However, there is no information available about this family in Artemisia argyi, a well-known traditional medicinal plant with great economic value.ResultsA total of 34 AaTIFY genes were identified, including 4 TIFY, 22 JAZ, 5 PPD, and 3 ZML genes. Structural, motif scanning, and phylogenetic relationships analysis of these genes revealed that members within the same group or subgroup exhibit similar exon-intron structures and conserved motif compositions. The TIFY genes were unevenly distributed across the 15 chromosomes. Tandem duplication events and segmental duplication events have been identified in the TIFY family in A. argyi. These events have played a crucial role in the gene multiplication and compression of different subfamilies within the TIFY family. Promoter analysis revealed that most AaTIFY genes contain multiple cis-elements associated with stress response, phytohormone signal transduction, and plant growth and development. Expression analysis of roots and leaves using RNA-seq data revealed that certain AaTIFY genes showed tissue-specific expression patterns, and some AaTIFY genes, such as AaTIFY19/29, were found to be involved in regulating salt and saline-alkali stresses. In addition, RT-qPCR analysis showed that TIFY genes, especially AaTIFY19/23/27/29, respond to a variety of hormonal treatments, such as MeJA, ABA, SA, and IAA. This suggested that TIFY genes in A. argyi regulate plant growth and respond to different stresses by following different hormone signaling pathways.ConclusionTaken together, our study conducted a comprehensive identification and analysis of the TIFY gene family in A. argyi. These findings suggested that TIFY might play an important role in plant development and stress responses, which laid a valuable foundation for further understanding the function of TIFY genes in multiple stress responses and phytohormone crosstalk in A. argyi.

Genome-wide identification of the endonuclease family genes implicates potential roles of TaENDO23 in drought-stressed response and grain development in wheat

BackgroundEndonucleases play a crucial role in plant growth and stress response by breaking down nuclear DNA. However, the specific members and biological functions of the endonuclease encoding genes in wheat remain to be determined.ResultsIn this study, we identified a total of 26 TaENDO family genes at the wheat genome-wide level. These genes were located on chromosomes 2 A, 2B, 2D, 3 A, 3B, and 3D and classified into four groups, each sharing similar gene structures and conserved motifs. Furthermore, we identified diverse stress-response and growth-related cis-elements in the promoter of TaENDO genes, which were broadly expressed in different organs, and several TaENDO genes were significantly induced under drought and salt stresses. We further examined the biological function of TaENDO23 gene since it was rapidly induced under drought stress and exhibited high expression in spikes and grains. Subcellular localization analysis revealed that TaENDO23 was localized in the cytoplasm of wheat protoplasts. qRT-PCR results indicated that the expression of TaENDO23 increased under PEG6000 and abscisic acid treatments, but decreased under NaCl treatment. TaENDO23 mainly expressed in leaves and spikes. A kompetitive allele-specific PCR (KASP) marker was developed to identify single nucleotide polymorphisms in TaENDO23 gene in 256 wheat accessions. The alleles with TaENDO23-HapI haplotypes had higher grain weight and size compared to TaENDO23-HapII. The geographical and annual frequency distributions of the two TaENDO23 haplotypes revealed that the elite haplotype TaENDO23-HapI was positively selected in the wheat breeding process.ConclusionWe systematically analyzed the evolutionary relationships, gene structure characteristics, and expression patterns of TaENDO genes in wheat. The expression of TaENDO23, in particular, was induced under drought stress, mainly expressed in the leaves and grains. The KASP marker of TaENDO23 gene successfully distinguished between the wheat accessions, revealing TaENDO23-HapI as the elite haplotype associated with improved grain weight and size. These findings provide insights into the evolution and characteristics of TaENDO genes at the genome-wide level in wheat, laying the foundation for further biological analysis of TaENDO23 gene, especially in response to drought stress and grain development.

Study on the response of ornamental plant growth on vetiver root mats for bio canvas development

Study on the response of ornamental plant growth on vetiver root mats for bio canvas development

SlCHP16 promotes root growth and enhances saline-alkali tolerance of tomato

With the increasing salinization in the world, crop growth and yield had a serious threat. Roots as the organ of the plant direct contact the saline-alkali environment has received more and more attention. The Divergent C1 (DC1) domain protein plays an important role in plant growth, development, and stress response. In this study, overexpression of SlCHP16 promoted tomato root growth, while knocking out SlCHP16 inhibited tomato root growth. In the roots of SlCHP16 overexpressing plants, the auxin synthesis key gene SlTAA2 was significantly up-regulated, which increased auxin synthesis and accumulation and promoted root cell elongation. Meanwhile, the expression levels of cell expanding-related genes SlLRP, SlXTH9 and SlEXPB1 were up-regulated. The opposite was observed in SlCHP16 knockout plants. Under saline-alkali stress, the root growth rate of SlCHP16 overexpressed lines was significantly higher than that of AC, and SlCHP16 knockout lines had poor root development during seed germination and seedling growth. At the same time, after saline-alkali stress treatment, SlCHP16-overexpressing lines showed higher tolerance, while SlCHP16 knockout plants were more sensitive to saline-alkali stress. In conclusion, SlCHP16 promoted root growth and enhanced saline-alkali tolerance in tomato. This work provides new insights into the mechanism of tomato root development and provides resources for developing new salt-alkali tolerant tomato varieties.

PavSPLs are key regulators of growth, development, and stress response in sweet cherry

SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes are plant-specific transcription factors essential for plant growth, development, and stress responses; however, their roles in sweet cherry are not well understood. In this study, we identified and isolated 16 SPL genes from the sweet cherry genome, categorizing them into five subfamilies, with 12 PavSPLs predicted as miR156 targets. The promoter regions of PavSPLs contain cis-elements associated with light, stress, and phytohormone responses, indicating their role in biological processes and abiotic stress responses. Seasonal expression analysis showed that PavSPL regulates sweet cherry recovery after dormancy. Gibberellin (GA) treatment reduced PavSPL expression, indicating its role in GA-mediated processes. Overexpression of PavSPL14 in Arabidopsis thaliana resulted in earlier flowering, increased plant height, and enhanced growth. Yeast two-hybrid assays revealed an interaction between PavSPL14 and DELLA protein PavDWARF8, suggesting the involvement of PavSPLs in GA-regulated processes through protein interactions. These findings lay the groundwork for future studies on PavSPL function in sweet cherry.

Different responses of soil bacterial community to plant-plant interactions under organic-inorganic fertilizers affect seedling establishment during subalpine forest succession.

Rhizosphere bacterial community as a valuable indicator of soil quality and function, has been widespread studied. However, little knowledge is about the response of bacterial communities to plant-plant interaction and different fertilizers during secondary forest succession. We conducted a field pot experiment applying organic and inorganic fertilizers to monocultures and mixed cultures of dominant plant species from mid- to late-successional stages (Salix oritrepha, Betula albosinensis, and Picea asperata), and investigated the responses of plant growth and rhizosphere bacterial communities. Results indicated that growth rate of plant height varied among plant species, but no significant differences were observed in soil bacterial diversity and composition among plant species or inter-specific interactions under control. Compared to control, inorganic fertilizer resulted in increases in plant growth and the relative abundance of Proteobacteria, Patescibacteria, Bacteroidetes and Gemmatimonadetes, while simultaneously leading to decrease in the relative abundance of Acidobacteria, Actinobacteria, Chloroflexi, Rokubacteria and Planctomycetes. When grown with other species, the bacterial communities in the mixture resembled those of S. oritrepha in singular monoculture under inorganic fertilizer treatment, but plant growth was not affected by interspecific interaction. Unlike inorganic fertilizer, organic fertilizer significantly affected bacterial communities and increased bacterial diversity, but did not alter the effects of plant-plant interactions on bacterial communities. It was also observed that organic fertilizer facilitated later successional species' growth (P. asperata and B. albosinensis) by the mid-successional species (S. oritrepha), ultimately facilitating secondary forest succession. In addition, plants at different successional stages harbor specific bacterial communities to affect their growth, and the bacterial communities contributed more than soil properties to the variations in the plant growth of S. oritrepha and P. asperata though the bacterial communities were regulated by soil factors. This finding highlights the significance of the rhizosphere bacteria on plant growth and plant community succession. It also emphasize the importance of considering both plant-plant interactions and diverse fertilizer types in forest restoration efforts and provide valuable insights into optimizing agronomic practices for secondary forest succession.

What determines transfer of carbon from plants to mycorrhizal fungi?

Biological Market Models are common evolutionary frameworks to understand the maintenance of mutualism in mycorrhizas. 'Surplus C' hypotheses provide an alternative framework where stoichiometry and source-sink dynamics govern mycorrhizal function. A critical difference between these frameworks is whether carbon transfer from plants is regulated by nutrient transfer from fungi or through source-sink dynamics. In this review, we: provide a historical perspective; summarize studies that asked whether plants transfer more carbon to fungi that transfer more nutrients; conduct a meta-analysis to assess whether mycorrhizal plant growth suppressions are related to carbon transfer; and review literature on cellular mechanisms for carbon transfer. In sum, current knowledge does not indicate that carbon transfer from plants is directly regulated by nutrient delivery from fungi. Further, mycorrhizal plant growth responses were linked to nutrient uptake rather than carbon transfer. These findings are more consistent with 'Surplus C' hypotheses than Biological Market Models. However, we also identify research gaps, and future research may uncover a mechanism directly linking carbon and nutrient transfer. Until then, we urge caution when applying economic terminology to describe mycorrhizas. We present a synthesis of ideas, consider knowledge gaps, and suggest experiments to advance the field.

The Effect Addition of Soil Amandments and PGPR (Plant Growth Promoting Rhizobacteria) on the Growth and Yield of Cotton Plants Intercropped with Corn Plants in Dry Land of North Lombok Regency of Indonesia

This research investigates the effect of soil amendments in the form of cow, form goat manures and PGPR biofertilizer on cotton plants intercropped with corn in the dry lands of North Lombok Regency. The research aims is to determine the growth and yield response of cotton plants due to the application of soil amendments and PGPR in an intercropped system with corn in dryland areas. The research was conducted from December 2023 to June 2024 in Andalan Village, Bayan District, North Lombok Regency. The method used is an experimental method with field trials. The design used was Randomized Block Design (RBD), incorporating two factors: soil amendment treatment (P) as the main plot and PGPR (K) concentration treatments as the subplot. Soil amendments consisted of three levels: P0 (no cow manure and no goat manure), P1 (20 tons/ha cow manure), P2 (20 tons/ha goat manure). PGPR concentration consisted of four levels: K0 (without PGPR), K1 (20 ml/liter PGPR application), K2 (30 ml/liter PGPR application), and K3 (40 ml/liter PGPR application). The research results indicated that the application of 20 tons/ha of goat manure (P2) produced the highest average across all observed parameters (plant height, number of leaves, branch number, stem diameter, and plant yield). Similarly, the application of 40 ml/liter PGPR produced the highest average for these observed parameters. Based on the results of the land equivalent ratio (LER) analysis, this integration system shows highly suitable and relevant to be applied in the dry lands of North Lombok.

Genome-wide identification and comprehensive analysis of the AP2/ERF gene family in Prunus sibirica under low-temperature stress

BackgroundAP2/ERF transcription factors are involved in the regulation of growth, development, and stress response in plants. Although the gene family has been characterized in various species, such as Oryza sativa, Arabidopsis thaliana, and Populus trichocarpa, studies on the Prunus sibirica AP2/ERF (PsAP2/ERF) gene family are lacking. In this study, PsAP2/ERFs in P. sibirica were characterized by genomic and transcriptomic analyses.ResultsIn the study, 112 PsAP2/ERFs were identified and categorized into 16 subfamilies. Within each subfamily, PsAP2/ERFs exhibited similar exon-intron structures and motif compositions. Additionally, 50 pairs of segmentally duplicated genes were identified within the PsAP2/ERF gene family. Our experimental results showed that 20 PsAP2/ERFs are highly expressed in leaves, roots, and pistils under low-temperature stress conditions. Among them, the expression of PsAP2/ERF21, PsAP2/ERF56 and PsAP2/ERF88 was significantly up-regulated during the treatment period, and it was hypothesised that members of the PsAP2/ERF family play an important role inlow temperature stress tolerance.ConclusionsThis study improves our understanding of the molecular basis of development and low-temperature stress response in P. sibirica and provides a solid scientific foundation for further functional assays and evolutionary analyses of PsAP2/ERFs.

Transcription factor ZmNAC19 promotes embryo development in Arabidopsis thaliana.

Overexpression of ZmNAC19, a NAC transcription factor gene from maize, improves embryo development in transgenic Arabidopsis. NAC proteins are plant-specific transcription factors that are involved in multiple aspects of plant growth, development and stress response. Although functions of many NAC transcription factors have been elucidated, little is known about their roles in seed development. In this study, we report the function of a maize NAC transcription factor ZmNAC19 in seed development. ZmNAC19 is highly expressed in embryos of developing maize seeds. ZmNAC19 localizes to nucleus and exhibits transactivation activity in yeast cells. Overexpression of ZmNAC19 in Arabidopsis significantly increases seed size and seed yield. During 3 to 7days after flowering, embryos of ZmNAC19-overexpression Arabidopsis lines developed faster compared to Col-0, while no visible differences were detected for their endosperms. Furthermore, overexpression of ZmNAC19 in Arabidopsis leads to increased transcription levels of two embryo development-related genes YUC1 and RGE1, and several elements proven to be binding sites of NAC transcription factors were observed in promoters of these two genes. Taken together, these results suggest that ZmNAC19 acts as a positive regulator in plant embryo development.

Ectopic and transient expression of VvDIR4 gene in Arabidopsis and grapes enhances resistance to anthracnose via affecting hormone signaling pathways and lignin production.

DIR (Dirigent) proteins play important roles in the biosynthesis of lignin and lignans and are involved in various processes such as plant growth, development, and stress responses. However, there is less information about VvDIR proteins in grapevine (Vitis vinifera L). In this study, we used bioinformatics methods to identify members of the DIR gene family in grapevine and identified 18 VvDIR genes in grapevine. These genes were classified into 5 subfamilies based on phylogenetic analysis. In promoter analysis, various plant hormones, stress, and light-responsive cis-elements were detected. Expression profiling of all genes following Colletotrichum gloeosporioides infection and phytohormones (salicylic acid (SA) and jasmonic acid (JA)) application suggested significant upregulation of 17 and 6 VvDIR genes, respectively. Further, we overexpressed the VvDIR4 gene in Arabidopsis thaliana and grapes for functional analysis. Ectopic expression of VvDIR4 in A. thaliana and transient expression in grapes increased resistance against C. gloeosporioides and C. higginsianum, respectively. Phenotypic observations showed small disease lesions in transgenic plants. Further, the expression patterns of genes having presumed roles in SA and JA signaling pathways were also influenced. Lignin contents were measured before and after C. higginsianum infection; the transgenic A. thaliana lines showed higher lignin content than wild-type, and a significant increase was observed after C. higginsianum infection. Based on the findings, we surmise that VvDIR4 is involved in hormonal and lignin synthesis pathways which regulate resistance against anthracnose. Our study provides novel insights into the function of VvDIR genes and new candidate genes for grapevine disease resistance breeding programs.

Characterisation and evolution of the PRC2 complex and its functional analysis under various stress conditions in rice

The polycomb repressive complex 2 (PRC2) is a chromatin-associated methyltransferase responsible for catalysing the trimethylation of H3K27, an inhibitory chromatin marker associated with gene silencing. This enzymatic activity is crucial for normal organismal development and the maintenance of gene expression patterns that preserve cellular identity, subsequently influencing plant growth and abiotic stress responses. Therefore, in this study, we investigated the evolutionary characteristics and functional roles of PRC2 in plants. We identified 209 PRC2 genes, including E(z), Su(z), Esc, and Nurf55 families, using 18 representative plant species and revealed that recent gene replication events have led to an expansion in the Nurf55 family, resulting in a greater number of members compared to the E(z), Su(z), and Esc families. Furthermore, protein structure and motif composition analyses highlighted the potential functional site regions within PRC2 members. In addition, we selected rice, a representative monocotyledonous plant, as the model species for food crops. Our findings revealed that SDG711, SDG718, and MSI1-5 genes were induced by abscisic acid (ABA) and/or methyl jasmonate (MeJA) hormones, suggesting that these genes play an important role in abiotic stress and disease resistance. Further experiments involving rice blast fungus treatments confirmed that the expression of SDG711 and MSI1-5 was induced by Magnaporthe oryzae strain GUY11. Multiple protein interaction assays revealed that the M. oryzae effector AvrPiz-t interacts with PRC2 core member SDG711 to increase H3K27me3 levels. Notably, inhibition of PRC2 or mutation of SDG711 enhanced rice resistance to M. oryzae. Collectively, these results provide new insights into PRC2 evolution in plants and its significant functions in rice.

Genome-Wide Identification of the Remorin Gene Family in Poplar and Their Responses to Abiotic Stresses.

The Remorin (REM) gene family is a plant-specific, oligomeric, filamentous family protein located on the cell membrane, which is important for plant growth and stress responses. In this study, a total of 22 PtREMs were identified in the genome of Populus trichocarpa. Subcellular localization analysis showed that they were predictively distributed in the cell membrane and nucleus. Only five PtREMs members contain both Remorin_C- and Remorin_N-conserved domains, and most of them only contain the Remorin_C domain. A total of 20 gene duplication pairs were found, all of which belonged to fragment duplication. Molecular evolutionary analysis showed the PtREMs have undergone purified selection. Lots of cis-acting elements assigned into categories of plant growth and development, stress response, hormone response and light response were detected in the promoters of PtREMs. PtREMs showed distinct gene expression patterns in response to diverse stress conditions where the mRNA levels of PtREM4.1, PtREM4.2 and PtREM6.11 were induced in most cases. A co-expression network centered by PtREMs was constructed to uncover the possible functions of PtREMs in protein modification, microtube-based movement and hormone signaling. The obtained results shed new light on understanding the roles of PtREMs in coping with environmental stresses in poplar species.

Screening and Identification of Target Gene of StTCP7 Transcription Factor in Potato

TCP transcription factors are involved in the regulation of plant growth and development and response to stress. Previous studies showed that StTCP7 was involved in the abiotic stress response of potato and positively regulated plant tolerance to drought stress. On the basis of previous studies, this study verified the downstream target genes of StTCP7 transcription factor binding through yeast one hybridization, double luciferase and other technologies, and conducted a preliminary analysis of the downstream target genes. The results showed that the StTCP7 transcription factor could bind the promoter region of StDAM5 and StGOLS2 and regulate the expression of their genes. qRT-PCR analysis showed that the expression level of StDAM5 gene was the highest in flower stalk tissue and the lowest in leaf stalk. The expression of StGOLS2 gene was the highest in stem, the second in stalk, and the lower in root. Both StDAM5 and StGOLS2 genes responded to abiotic stress treated with 200 mM NaCl, 20% PEG-6000 and 100 µM ABA. The expression levels of target genes StDAM5 and StGOLS2 were up-regulated in StTCP7 interfered plants. The protein encoded by the target gene StDAM5 belongs to the Type II MADS-box protein, which contains 238 amino acids and is an acidic hydrophilic protein. The analysis of StDAM5 promoter region showed that the promoter region of StDAM5 gene contained cis-acting elements such as light response and abscisic acid. Subcellular localization showed that StDAM5 protein was expressed in both nucleus and cytoplasm.

Transcription factor gene TaWRKY76 confers plants improved drought and salt tolerance through modulating stress defensive-associated processes in Triticum aestivum L.

WRKY transcription factor (TF) family acts as essential regulators in plant growth and abiotic stress responses. This study reported the function of TaWRKY76, a member of WRKY TF family in Triticum aestivum L., in regulating plant osmotic stress tolerance. TaWRKY76 transcripts were significantly upregulated upon drought and salt signaling, with dose extent- and stress temporal-dependent manners. Plant GUS activity assays suggested that stress responsive cis-acting elements, such as DRE and ABRE, exert essential roles in defining gene transcription under osmotic stress conditions. The TaWRKY76 protein targeted onto nucleus and possessed ability interacting with TaMYC2, a MYC TF member of wheat. TaWRKY76 and TaMYC2 positively regulated plant drought and salt adaptation by modulating osmotic stress-related physiological indices, including osmolyte contents, stomata movement, root morphology, and reactive oxygen species (ROS) homeostasis. Yeast one-hybrid assay indicated the binding ability of TaWRKY76 with promoters of TaDREB1;1, TaNCEB3, and TaCOR15;4. ChIP-PCR analysis confirmed that the osmotic stress genes are transcriptionally regulated by TaWRKY76. Moreover, the transgenic lines with knockdown of these stress-response genes displayed lowered plant biomass together with worsened root growth traits, decreased proline contents, and elevated ROS amounts. These results suggested that these stress defensive genes contributed to TaWRKY76-modulated osmotic stress tolerance. Highly positive correlations were observed between yield and the transcripts of TaWRKY76 in a wheat variety panel under field drought condition. A major haplotype TaWRKY76 Hap1 conferred improved drought tolerance. Our results suggested that TaWRKY76 is essential in plant drought and salt adaptation and a valuable target for molecular breeding stress-tolerant cultivars in Triticum aestivum L..

Genome-Wide Identification of the bHLH Gene Family in Rhododendron delavayi and Its Expression Analysis in Different Floral Tissues.

The bHLH genes play a crucial role in plant growth, development, and stress responses. However, there is currently limited research on bHLH genes in the important horticultural plant Rhododendron delavayi Franch. In this study, we conducted a comprehensive genome-wide identification and in-depth analysis of the bHLH gene family in R. delavayi using bioinformatics approaches. A total of 145 bHLH family members were identified, encoding proteins ranging from 98 to 3300 amino acids in length, with molecular weights ranging from 11.44 to 370.51 kDa and isoelectric points ranging from 4.22 to 10.80. These 145 bHLH genes were unevenly distributed across 13 chromosomes, with three bHLH genes located on contig 52. Chromosome 8 contained the highest number of bHLH family members with 19 genes, while chromosomes 9 and 13 had the lowest, with 7 genes each. Phylogenetic analysis revealed a close evolutionary relationship between bHLH genes in R. delavayi and Arabidopsis thaliana. Subcellular localization analysis indicated that most bHLH genes were located in the nucleus. Promoter analysis of R. delavayi bHLH genes revealed the presence of various cis-regulatory elements associated with light responses, methyl jasmonate responses, low-temperature responses, and coenzyme responses, suggesting that bHLH genes are involved in multiple biological processes in R. delavayi. Through transcriptome analysis, we identified three key functional genes-Rhdel02G0041700, Rhdel03G0013600, and Rhdel03G0341200-that may regulate flower color in R. delavayi. In conclusion, our study comprehensively identified and analyzed the bHLH gene family in R. delavayi and identified three bHLH genes related to flower color, providing a foundation for molecular biology research and breeding in R. delavayi.

Strigolactone enhances tea plant adaptation to drought and Phyllosticta theicola petch by regulating caffeine content via CsbHLH80

Strigolactones (SLs) play crucial roles in both plant growth and stress responses. However, their impact on the secondary metabolites of woody plants remains elusive. Here, we found that exogenous strigolactone analogue GR24 positively regulates tea plant flavor secondary metabolites, concurrently inhibiting caffeine biosynthesis and promoting the accumulation of caffeine catabolic pathway products. In this process, SL directly or indirectly inhibits the expression of CsSAMSs by inducing CsbHLH80, thereby reducing caffeine biosynthesis. Furthermore, CsbHLH80 enhances caffeine degradation, leading to increased allantoin. Under normal conditions, heightened allantoin reduces abscisic acid (ABA) accumulation. This inhibition reverses under drought stress. Increased ABA significantly enhances tea plant tolerance to both drought and Phyllosticta theicola Petch. In summary, this study offers novel insights for improving tea plant adaptation and quality in arid regions, particularly emphasizing the selection of stress-tolerant varieties and the refinement of production measures with a focus on high-quality production and environmentally friendly biological control methods.

Integrative Analysis of Transcriptome and Metabolome Reveals the Pivotal Role of the NAM Family Genes in Oncidium hybridum Lodd. Pseudobulb Growth.

Oncidium hybridum Lodd. is an important ornamental flower that is used as both a cut flower and a potted plant around the world; additionally, its pseudobulbs serve as essential carriers for floral organs and flower development. The NAM gene family is crucial for managing responses to various stresses as well as regulating growth in plants. However, the mechanisms by which NAM genes regulate the development of pseudobulbs remain unclear. In this study, a total of 144 NAM genes harboring complete structural domains were identified in O. hybridum. The 144 NAM genes were systematically classified into 14 distinct subfamilies via phylogenetic analysis. Delving deeper into the conserved motifs revealed that motifs 1-6 exhibited remarkable conservation, while motifs 7-10 presented in a few NAM genes only. Notably, NAM genes sharing identical specific motifs were classified into the same subfamily, indicating functional relatedness. Furthermore, the examination of occurrences of gene duplication indicated that the NAM genes display 16 pairs of tandem duplications along with five pairs of segmental duplications, suggesting their role in genetic diversity and potential adaptive evolution. By conducting a correlation analysis integrating transcriptomics and metabolomics at four stages of pseudobulb development, we found that OhNAM023, OhNAM030, OhNAM007, OhNAM019, OhNAM083, OhNAM047, OhNAM089, and OhNAM025 exhibited significant relationships with the endogenous plant hormones jasmonates (JAs), hinting at their potential involvement in hormonal signaling. Additionally, OhNAM089, OhNAM025, OhNAM119, OhNAM055, and OhNAM136 showed strong links with abscisic acid (ABA) and abscisic acid glucose ester (ABA-GE), suggesting the possible regulatory function of these NAM genes in plant growth and stress responses. The 144 NAM genes identified in this study provide a basis for subsequent research and contribute to elucidating the intricate molecular mechanisms of NAM genes in Oncidium and potentially in other species.

CfSGR1 and CfSGR2 from Cryptomeria fortunei exhibit contrasting responses to hormones and abiotic stress in transgenic Arabidopsis

Stay-green (SGR) genes are pivotal regulatory genes in the context of plant chlorophyll metabolism, but few studies on SGR homologues in Cryptomeria fortunei have been previously reported. We cloned two CfSGR genes and overexpressed them in Arabidopsis to explore their functions. Full-length CfSGR1 and CfSGR2 are 1265 and 1197 bp, encompassing open reading frames (ORFs) encoding 274 and 276 amino acids, respectively. SGRs exhibited high conservation in higher plants, and phylogenetic analysis indicated that SGRs from monocots and gymnosperms cluster in a clade. The proteins localized to chloroplasts and showed no transcriptional activity in yeast cells. The CfSGR gene expressions were induced by abiotic stresses and hormones. Under conditions of darkness, abscisic acid (ABA), salt, drought, or freezing stress, CfSGR2-transgenic Arabidopsis exhibited a delay in leaf yellowing compared to the WT, which was attributed to increased chlorophyll content and enhanced photosynthetic capacity. These transgenic plants exhibited improved resistance to stress via upregulated expression of resistance-related genes, increased antioxidant enzyme activities, and reduced malondialdehyde content and electrolyte leakage rate. In contrast, CfSGR1-transgenic plants may accelerate leaf yellowing and exhibit reduced stress resistance. Our findings highlight potential divergence in the functions of CfSGR genes concerning plant growth and development and responses to abiotic stresses or hormones, providing a scientific foundation for future breeding of stress-resistant C. fortunei cultivars.

Identification of the ribosomal protein L18 (RPL18) gene family reveals that TaRPL18-1 positively regulates powdery mildew resistance in wheat

The Ribosomal protein L18 (RPL18) protein gene family plays an important role in plant growth, development and stress response. Although the RPL18 genes have been identified in several plant species, the RPL18 gene family in wheat (Triticum aestivum) is still unexplored. This study found 8 TaRPL18 genes, each of which has a significantly different gene sequence length and is evenly distributed on the chromosome; Additionally, these proteins have similar physicochemical characteristics as well as secondary and tertiary structures. 17 RPL18 genes in 4 species (wheat, Arabidopsis, rice, and maize) were classified into 5 groups, and the TaRPL18 genes within the same group showed similar structures and conserved motifs. Analysis of the cis-acting elements in the TaRPL18 genes promoter regions revealed the presence of developmental and stress-responsive elements in the majority of the genes. Through yeast two-hybrid (Y2H) experiments, it was confirmed that the powdery mildew resistance protein TaPm46 physically interacts with the Class IV TaRPL18-1. Functional analysis indicated that TaRPL18-1-silenced wheat plants show reduced resistance to powdery mildew compared to the wild type (WT), with decreased expression levels of PAL and PPO genes, and increased expression levels of the PR gene. The findings of this study provide a basis for clarifying the function of the TaRPL18 genes and will be useful for the selection of disease-resistant varieties of wheat.