Hydrogen sulfide (H2S), a gaseous signaling molecule, retards plant senescence and fruit ripening via protein persulfidation. However, the molecular mechanism underlying its coordination of fruit ripening with plant growth and development remains undefined. This study found that H2S could delay tomato fruit ripening and leaf senescence, and H2S defective mutant sllcd1 shows premature fruit ripening and stunted growth. Overexpression of SlWRKY6, which could be persulfidated by H2S, promotes fruit ripening and reduces fruit number. Molecular assays demonstrated that SlWRKY6 directly binds to the promoter of SlGIF2, a transcriptional co-activator, to repress its expression. Notably, H2S attenuates the repressive effect through persulfidation of SlWRKY6 to increase SlGIF2 transcription. Furthermore, SlGIF2 physically interacts with the GROWTH-REGULATING FACTOR 1 (SlGRF1). Functional validation showed that SlGRF1-SlGIF2 complex serves as a positive regulator of tomato plant growth and fruit yield while concomitantly delaying fruit ripening. Conversely, slgrf1 gene-edited mutants exhibit reduced plant growth, fruit yield and accelerated ripening. Mechanistically, SlGRF1-SlGIF2 complex synergistically activates two downstream target genes: SlCYCD3;1, a key cell-cycle regulator required for cell proliferation and plant growth, and SlCBSX5, which encodes an H2S biosynthesis enzyme that retards fruit ripening. This study provides a module that SlWRKY6-SlGRF1-SlGIF2 integrates H2S signal and genetically coordinates plant growth, fruit yield and fruit ripening in tomato.

Fruit aroma is a key factor shaping the commercial value of pears. MYB and ERF transcription factors (TFs) are involved in regulating the biosynthesis of fruit aroma compounds, yet the mechanisms underlying their synergistic regulation of pear aroma formation remain elusive. Calcium signaling exerts an important role in fruit aroma biosynthesis; nevertheless, how calcium signaling mediates MYB-ERF transcription factors to participate in pear aroma biosynthesis remains unclear. Here, transcriptomic profiling of calcium-treated pear fruits screened two significantly upregulated TFs, PuMYB44 and PuERF118, as candidate genes. Phylogenetic analysis and conserved domain characterization further suggested that these two genes may be involved in regulating fatty acid biosynthesis. Transient overexpression experiments in pear fruits revealed that the co-expression of PuMYB44 and PuERF118 synergistically activated a set of fatty acid biosynthesis genes, including PuFAD2, PuFAD3, PuFAD8, PuLOX5, PuLOX21, and PuSCD. Meanwhile, the co-expression markedly increased the contents of key aroma volatiles, such as ethyl acetate, 1-hexanol, ethyl 2-methylbutyrate and hexadecane. Yeast two-hybrid and luciferase complementation assays confirmed an interaction between PuMYB44 and PuERF118. Analysis of the PuFAD8 promoter sequence revealed a conserved MYB-binding motif and an ERF-responsive cis-acting element. Dual-luciferase reporter assays further confirmed that both PuMYB44 and PuERF118 can independently activate PuFAD8 transcription, and that the synergistic activation effect resulting from the co-expression of these two factors is significantly stronger than that observed when either factor is expressed alone. In summary, this study elucidated a calcium-responsive transcriptional module underlying the biosynthesis of pear aroma and provided potential molecular targets for improving the flavor quality of pear fruit.

Ethylene promotes fruit ripening, while hydrogen sulfide (H2S) exerts the opposite effects. However, whether H2S antagonizes ethylene-mediated regulatory mechanisms of post-harvest banana pulp ripening and senescence remains unclear. In this study, H2S alone or in combination with ethylene fumigation delayed the yellowing of banana peels by downregulating the expression of chlorophyll degradation genes (MaNYC1, MaSGR1, MaPPH and MaPAO) and prolonged the pulp softening process and reduced the release of endogenous ethylene by comparing to the control treatment. The effect on banana pulp is manifested with the preservation of nutrients, such as starch and soluble protein content, as well as the reduction of the generation of reactive oxygen species (ROS), including superoxide anion (center dot O-2) and hydrogen peroxide (H2O2), inhibiting lipid peroxidation to decrease malondialdehyde (MDA) production, while simultaneously enhancing ABTS radical scavenging rates and antioxidant enzyme activity. Bioinformatics analysis results demonstrated that H2S antagonizes ethylene by affecting the changes in fruit quality in banana pulp. Molecular analysis further revealed that the exogenous application of H2S downregulated the expression of MaACS1, MaPL, MaGWD1 and MaAMY3 genes. Collectively, these results evidence that exogenous H2S application effectively antagonized the effect of ethylene, thereby maintaining nutrient content and antioxidant enzyme activities in postharvest banana fruit.

Biaxially oriented polyethylene (BOPE) is a high-strength, lightweight polyethylene material with superior barrier properties. In this study, peaches were packaged using either polyethylene (PE) or BOPE film. The peaches packaged in BOPE film maintained better firmness, color retention, antioxidant content, and nutritional quality than control peaches and those packaged in PE film. Transcriptome sequencing revealed 1041 differentially expressed genes in BOPE-packaged fruit compared with that in the control, and these were enriched in the pyruvate metabolism, flavonoid biosynthesis, and glutathione metabolism pathways. Physiological analyses demonstrated that BOPE packaging reduced malondialdehyde accumulation and increased peroxidase and phenylalanine ammonia-lyase activity, potentially limiting membrane peroxidation and senescence. BOPE-packaged fruit also retained higher levels of soluble sugars, reducing sugars, free amino acids, and proline, which are critical for fruit flavor and stress adaptation. Together, these results underscore the potential of BOPE as a novel packaging material for the preservation of fruits and vegetables.

Soil naturally contains various heavy metals, however, their concentrations have reached toxic levels due to excessive agrochemical use and industrial activities. Heavy metals are persistent and non-biodegradable, causing environmental disruption and posing significant health hazards. Microbial-mediated remediation is a promising strategy to prevent heavy metal leaching and mobilization, facilitating their extraction and detoxification. Nickel (Ni), being a prevalent heavy metal pollutant, requires specific attention in remediation efforts. Plants have evolved defense mechanisms to cope with environmental stresses, including heavy metal toxicity, but such stress significantly reduces crop productivity. Beneficial microorganisms play a crucial role in enhancing plant yield and mitigating abiotic stress. The impact of heavy metal abiotic stress on plants’ growth and productivity requires thorough investigation. Bioremediation using Nickel nanoparticles (Ni NPs) offers an effective approach to mitigating environmental pollution. Microorganisms contribute to nanoparticle bioremediation by immobilizing metals or inducing the synthesis of remediating microbial enzymes. Understanding the interactions between microorganisms, contaminants, and nanoparticles (NPs) is essential for advancing bioremediation strategies. This review focuses on the role of Bacillus subtilis in the bioremediation of nickel nanoparticles to mitigate environmental pollution and associated health risks. Furthermore, sustainable approaches are necessary to minimize metal contamination in seeds. The current review discusses bacterial inoculation in enhancing heavy metal tolerance, plant signal transduction pathways, and the transition from molecular to genomic research in metal stress adaptation. Moreover, the inoculation of advantageous bacteria is crucial for preserving plants under severe mental stress. Different researchers develop a complex, vibrant relationship with plants through a series of events known as plant-microbe interactions. It increases metal stress resistance through the creation of phytohormones. In general, the defensive responses of plants to heavy metal stress, mediated by microbial inoculation require further in-depth research. Further studies should explore the detoxification mechanism of nickel through bioremediation to develop more effective and sustainable remediation strategies.

Hydrogen sulfide (H2S), as a signaling molecule, is found to delay fruit ripening and senescence by antagonizing the biosynthesis and signaling of ethylene, whereas the mechanism remains unclear. In the current work, exogenous H2S fumigation could alleviate tomato fruit ripening and an ethylene response factor SlERF.D2 was found to be persulfidated at Cys35 by mass spectrometry analysis. Meanwhile, ethylene biosynthesis related genes SlACS1 and SlACO3 were significantly downregulated at gene expression level in H2S-treated fruit. By CRISPR/Cas9 and gene overexpression, we showed that overexpression of SlERF.D2 promoted fruit ripening by accelerating chlorophyll degradation and carotenoid accumulation and upregulating the expression of ripening related genes SlPAO, SlPPH, SlSGR1, SlACS1, SlACS2, SlACS4, SlEIN2, SlACO1, and SlACO3, while the mutation of slerf.d2 delayed fruit ripening. Additionally, slerf.d2 mutant showed delayed ethylene production during tomato fruit ripening. Moreover, SlERF.D2 was found to interact with the kinase SlMAPK4 and was phosphorylated at Ser42 by yeast two-hybrid screening, pull down and LC-MS/MS. By cis-element analysis, electrophoretic mobility shift assay and dual-luciferase assay, SlERF.D2 could activate the transcription of the ethylene pathway-associated gene SlACO3 and SlEIN2. Besides, we provided evidence that SlERF.D2 persulfidation weakened the transcriptional activity of SlERF.D2 on the target gene SlACO3 and SlEIN2. In contrast, SlMAPK4-mediated phosphorylation enhanced SlERF.D2's transcriptional activation activity on SlACO3 and SlEIN2. Therefore, the present research provides insights into the mechanism of H2S in antagonizing the biosynthesis and signaling transduction of ethylene and reveals the importance of SlERF.D2 persulfidation and phosphorylation in dynamically regulating tomato fruit ripening.

Leaf senescence in plants is a coordinated cell death process that impacts the post-harvest performance horticultural plants. While the mechanisms of leaf senescence have been extensively studied, the translational control of this process remains largely unexplored. In this study, we demonstrated that leaf senescence chrysanthemum is controlled by mRNA m6A methylation-mediated translational regulation. We found that methylation is decreased during leaf senescence. Inhibiting the expression of the m6A eraser CmALKBH10B leads to increased m6A modifications and delayed leaf senescence, whereas overexpression of CmALKBH10B results reduced m6A levels and accelerated senescence. The majority of genes differentially modified by m6A exhibited no significant changes at the expression level, implying that translational regulation may contribute to senescence. Genetic and molecular evidences indicated that m6A modification impacts the translation efficiency of CmEIN2 gene, thereby influencing leaf senescence. Our findings provide crucial insights into the translational regulatory mechanism of leaf senescence, adding another layer of complexity to the comprehensive regulatory networks governing this process.

Sulfur dioxide (SO2) is a potential signaling molecule, playing a crucial role in regulating multiple physiological processes in organisms. In the present study, we investigate the impact of SO2 on the germination rate of wheat seed subjected to drought stress. Drought stress was stimulated using polyethylene glycol 6000, and the findings revealed that SO2 pretreatment significantly enhanced the germination rate of wheat grain. Additionally, SO2 pretreatment resulted in increased levels of reducing sugars and soluble proteins, as well as elevated amylase activity. Furthermore, SO2 pretreatment of wheat grain significantly reduced the content of superoxide anion, hydrogen peroxide, and malondialdehyde, while increasing the activities of peroxidase (POD), ascorbate peroxidase and catalase. Additionally, SO2 pretreatment was associated with a decrease in lipoxygenase activity and an increase in the levels of endogenous hydrogen sulfide. Principal component analysis revealed that POD is the most influential factor in the seed germination process. These findings suggest that SO2 pretreatment may enhance the germination of wheat grain under drought conditions by facilitating the mobilization of storage materials and improving antioxidant capacity during the germination phase.

Cyanide is produced along with ethylene biosynthesis and beta-cyanoalanine synthase (CAS) plays a crucial role in cyanide detoxification in plants, and its activity increases with fruit ripening. However, the involvement of CAS in pigment metabolism and ethylene biosynthesis during fruit ripening has not been previously reported. In this study, SlCAS1/2 were identified as highly homologous to StCAS1/2 in potato. Among them, SlCAS1 had higher expression level than SlCAS2 during tomato fruit ripening. The silencing of SlCAS1 expression by virus induced gene silencing (VIGS) increased chlorophyll content, decreased anthocyanins accumulation and affected the expression of SlNYC1, SlPPH, SlPAO and SlACO1/3 by comparing with the control. Conversely, overexpression of SlCAS1 (SlCAS1-OE) altered pigment accumulation, upregulated the expression of key anthocyanin biosynthesis genes such as SlDFR and SlANS, and increased the expression of key ethylene metabolism-related genes including SlACS2, SlACS4, SlRIN, and SlNOR, compared to the wild type. In contrast, Slcas1 mutant fruit (Delta SlCAS1) generated by CRISPR/Cas9 technology showed the opposite trend. Transcriptomic analysis comparing the wild type, SlCAS1-OE and Delta SlCAS1 fruit, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these DEGs were mainly involved in ethylene biosynthesis, fruit ripening, and flavonoid biosynthesis. Principal component analysis (PCA) identified anthocyanin, SlACS2 and SlACO3 as the main factors. Overall, these results showed that SlCAS1 mediated tomato fruit ripening by enhancing anthocyanin and ethylene biosynthesis. These findings provide a new basis for improving tomato fruit color and ripening, offering potential strategies for improving tomato fruit quality.

Hydrogen sulfide (H2S) is a gaseous signaling molecule that extends the postharvest storage period of fruit. Biaxially oriented polyethylene (BOPE) films are widely used in fruit packaging due to their excellent properties. By analyzing the phenotypic characteristics of strawberry fruits by comparing with the control, PE and BOPE or in combination with H2S at 4 degrees C, it was shown that the H2S+BOPE treatment reduced decay and water loss, and maintained the best lustre and firmness than other groups. A total of 7,258 co-differentially expressed genes (DEGs) were identified by comparing H2S, H2S+PE and H2S+BOPE with Control by transcriptome analysis. GO, WGCNA and KEGG analyses showed that DEGs were mainly enriched in starch and sucrose metabolism, pigment metabolism and antioxidant activity from the MEyellow and MEblack modules. Moreover, these candidate genes were screened, and the expression level of CHS, PAL and DFR were significantly decreased in H2S+BOPE group than other groups by RT-qPCR. Physiological assessments indicated that H2S+BOPE treatment significantly delayed chlorophyll degradation, anthocyanin accumulation and TA content, increased reducing sugar content, carotenoid and POD activity, and maintained low MDA content in strawberries. PCA and heatmap showed that POD and pigments were main factors and the correlation analysis proved that POD activity exhibited a positive correlation with the expression of DFR (0.57) and bHLH3 (0.56), carotenoid content (0.54), and it showed a negative correlation with chlorophyll contents (-0.37). These results indicated that BOPE could effectively improve the appearance and antioxidant activity of strawberry fruits, thereby prolonging their postharvest storage period.

As the common foodborne mycotoxins with the highest pollution rate, deoxynivalenol (DON, also named “vomitoxin”) can harm the health of humans and animals by causing anorectic response. It has four congeners: 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), nivalenol (NIV), and fusarenon X (FX). These five mycotoxins have been associated with the detrimental effect on food intake. However, its underlying mechanism of anorexia remains unclear. The goal of this research was to compare the anorectic responses to these five mycotoxins and relate these effects to proinflammatory cytokines interleukin-18 (IL-18) and interleukin-6 (IL-6) following intraperitoneal (IP) and oral exposure to a common dose at 2.5 mg/kg BW in mice. Plasma IL-18 and IL-6 were elevated within 1–2 h and returned to basal levels at 6 h after exposure to DON, 3-ADON and 15-ADON. FX promoted IL-18 expression at 6 h. Whereas, FX only promoted IL-6 at 6 h. When NIV was injected intraperitoneally, IL-18 started to rise at 1 h and peaked at 6 h. Whereas, NIV only promoted IL-18 at 2 h following oral exposure. IP exposure to NIV induced an increase in IL-6 that occurred only at 2 h. No effect on IL-6 when exposed orally to NIV. In conclusion, the data indicate that IL-18 and IL-6 play critical roles in anorectic response induced by DON and its four congeners 3-ADON, 15-ADON, NIV, FX.

Sweet potato (Ipomoea batatas L.) is a crop native to the tropics that is weakly resistant to cold. Low temperatures are important factors limiting its storage. By analyzing the phenotypic and tuberous root color differences between Xushu 32 and Yanshu 25 under low-temperature treatment, we found that Xushu 32 showed less low-temperature damage. Transcriptome analysis was performed on the tuberous roots of the two sweet potatoes at different storage times to further investigate the molecular mechanism. There were 7039 differentially co-expressed genes in Xushu 32 and 11033 differentially co-expressed genes in Yanshu 25 after 4 and 8 days of low-temperature treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the percentage of differentially expressed genes in the glutathione metabolism pathway in Xushu 32 was significantly higher than that in Yanshu 25. Weighted correlation network analysis (WGCNA) analysis indicated that the expression modules of MElightcyan1 and MEmegenta3 were up-regulated under low-temperature stress and that glutathione S-transferases (GSTs) were hub genes with high connectivity. The candidate genes IbGST2 and IbGST4 were highly similar to a rice glutathione S-transferase (GST) (Os10g0528900) by heatmap analysis and evolutionary tree analysis and may play a role in low-temperature stress. Subsequently, gene-silenced plants of the homologous genes SlBI-GST and SlGST-T4 in tomatoes were constructed using virus-induced gene silencing (VIGS) technology, and the contents of reactive oxygen species (ROS) metabolites and expression of BI-GST, GST-T4, and the C-repeat binding transcription factors (CBFs) were determined. This suggested that BI- GST and GST- T4 genes could scavenge ROS and improve the cold tolerance of tomatoes. These results provide important insights into the roles of IbGST2 and IbGST4 in the storage characteristics of sweet potatoes under low-temperature stress.

Calcium acts as a secondary messenger in plants and is essential for plant growth and development. However, studies on the pathway of aroma synthesis in 'Nanguo' pear (Pyrus ussriensis Maxim.) are scarce. In this study, a bioinformatics analysis of transcriptomic data from calcium-treated 'Nanguo' pear was performed, which identified two fatty acid desaturases, PuFAD2 and PuFAD3, and eight AP2/ERF transcription factors, all exhibiting the same expression patterns. Transient expression experiments showed overexpression of PuFAD2 and PuFAD3 significantly increased the levels of aromatic substrates linoleic acid, hexanal, linolenic acid, and (E)-2-hexenal, but RNAi (RNA interference) had the opposite expression. Promoter sequences analysis revealed that PuFAD2 and PuFAD3 have ERE (estrogen response element) motifs on their promoters. The strongest activation of PuFAD2 by PuERF008 was verified using a dual-luciferase reporting system. Additionally, yeast one-hybrid and electrophoretic mobility shift assays revealed PuERF008 could active PuFAD2. Transient overexpression and RNAi analyses of PuERF008 showed a strong correlation with the expression of PuFAD2. This study provides insights into the process of aroma biosynthesis in 'Nanguo' pear and offers a theoretical basis for elucidating the role of calcium signaling in aroma synthesis.

IntroductionAcer truncatum Bunge, belonging to the Acer genus in the Aceraceae family, is a commonly planted afforestation species across China, Japan, Korea, Europe, and North America. Renowned for its vibrant fall colors, it holds significant ecological and ornamental value.MethodsIn this study, Acer truncatum ' Lihong ' was used as the research object. Starting from the callus induction of explants, the embryogenic callus of Acer truncatum 'Lihong' was obtained by systematically optimizing the medium and culture conditions. Then, the candidate gene AtrGST894 screened by transcriptome sequencing was transformed into embryogenic callus by Agrobacterium-mediated transformation. The genetic transformation system of Acer truncatum 'Lihong' embryogenic callus was initially established by continuously adjusting the conditions of Agrobacterium tumefaciens infection receptor materials, thus laying a material foundation for the study of the molecular regulation mechanism of Acer truncatum 'Lihong' leaf color, and also preparing for the later molecular improvement breeding of Acer truncatum. Therefore, this study has important theoretical and practical significance.ResultsThe results showed that the best medium for callus induction of Acer truncatum was 1/2MS+2 mg/L 2,4-D+0.3 mg/L 6-BA+0.5 mg/L NAA; The embryogenic callus induction medium of Acer truncatum was 1/2MS+3.0mg/L 6-BA+2.0mg/L TDZ+0.5mg/L IBA+0.1mg/L GA3; The proliferation medium of embryogenic callus of Acer truncatum was WPM+1.0mg/L TDZ+0.5mg/L IBA+0.1mg/L GA3+3mg/L 6-BA+1.0mg/L KT; The infection experiment of Agrobacterium tumefaciens on the embryogenic callus of Acer truncatum showed that the best antibacterial medium was WPM+30g/L sucrose+8g/L agar+0.5g/L acid-hydrolyzed casein+0.2mg/L KT+1.0 mg/L TDZ+0.5 mg/L IBA+0.1 mg/L GA3+200mmol/L carboxybenzyl+200mg/L cephalosporin, and then WPM+30g/L sucrose+8g/L agar+0.5g/L acid-hydrolyzed casein+0.2mg/L KT+1.0 mg/L TDZ+0.5 mg/L IBA+0.1 mg/L GA3+300mmol/L carboxybenzyl+200mg/L cephalosporin+25mg/L hygromycin. Screening medium screening, The obtained embryogenic callus browning rate, pollution rate and mortality rate were the lowest, and maintained vigorous growth.DiscussionThe embryogenic callus was used as the infection material to verify that we successfully transferred the target gene into the embryogenic callus, which means that the genetic transformation system of Acer truncatum embryogenic callus was partially completed, and the infection process could be effectively inhibited. Although there was partial browning, it could continue to proliferate. Therefore, in future experiments, the focus is still to continue to verify the optimal conditions for optimizing the genetic transformation of Acer truncatum embryogenic callus and to solve the problems of difficulty in embryonic callus germination.

Hydrogen peroxide (H2O2) is relatively stable among ROS (reactive oxygen species) and could act as a signal in plant cells. In the present work, detached tomato leaves were treated with exogenous H2O2 at 10 mmol/L for 8 h to study the mechanism of how H2O2 regulates leaf senescence. The data indicated that H2O2 treatment significantly accelerated the degradation of chlorophyll and led to the upregulation of the expression of leaf senescence-related genes (NYC1, PAO, PPH, SGR1, SAG12 and SAG15) during leaf senescence. H2O2 treatment also induced the accumulation of H2O2 and malondialdehyde (MDA), decreased POD and SOD enzyme activities and inhibited H2S production by reducing the expression of LCD1/2 and DCD1/2. A correlation analysis indicated that H2O2 was significantly and negatively correlated with chlorophyll, the expression of leaf senescence−related genes, and LCD1/2 and DCD1/2. The principal component analysis (PCA) results show that H2S showed the highest load value followed by O2•−, H2O2, DCD1, SAG15, etc. Therefore, these findings provide a basis for studying the role of H2O2 in regulating detached tomato leaf senescence and demonstrated that H2O2 plays a positive role in the senescence of detached leaves by repressing antioxidant enzymes and H2S production.

Cysteine desulfhydrase catalyses the generation of the signaling molecule hydrogen sulfide (H2S) in plants. In this study, we found that H2S can inhibit tomato (Solanum lycopersicum) fruit ripening and SlWRKY6 undergoes differential protein persulfidation in SlLCD1-overexpressing leaves. Then, further study indicated that SlWRKY6 could be persulfidated by H2S at Cys396. By construction of slwrky6 mutants and SlWRKY6-OE lines, we found that SlWRKY6 positively regulates leaf senescence and fruit ripening by activating the transcription of ripening-related genes STAYGREEN 1 (SlSGR1) and Senescence-Associated Gene 12 (SlSAG12). In addition, SlWRKY6 interacted with kinase SlMAPK4 and was phosphorylated at Ser33. Dual-luciferase transient expression assays and electrophoretic mobility shift assays indicated that SlWRKY6 persulfidation attenuated its transcriptional regulation of target genes SlSGR1 and SlSAG12, whereas SlWRKY6 phosphorylation by SlMAPK4 activated the transcription of target genes to promote fruit ripening. Moreover, we provided evidence that SlWRKY6 persulfidation attenuated its SlMAPK4-mediated phosphorylation to inhibit tomato fruit ripening. By transient expression of SlWRKY6, SlWRKY6C396A, SlWRKY6S33A, and SlWRKY6S33D in slwrky6 fruits, we found that SlWRKY6 persulfidation attenuated the expression of SlSGR1 and SlSAG12 thereby delaying tomato fruit ripening, while SlWRKY6 phosphorylation increased the expression of target genes. As tomato fruits ripened, endogenous H2S production decreased, while SlMAPK4 expression increased. Therefore, our findings reveal a model in which SlWRKY6 persulfidation due to higher endogenous H2S levels in un-ripened fruit inhibits its ability to activate SlSGR1 and SlSAG12 expression, while SlWRKY6 phosphorylation by SlMAPK4 activates its transcriptional activity, thereby promoting tomato fruit ripening.

Taste quality is one of the most important indicators for assessing the quality of rice. However, there has been a lack of systematic studies investigating the impact factors of taste quality. In this study, chromosomal segment substitution lines (CSSLs) with notable differences in physicochemical properties were obtained by screening the CSSL population. A correlation analysis between the physicochemical properties and the taste qualities of rice revealed that amylose and protein content are significantly negatively correlated with the taste value of both freshly cooked and rehydrated instant rice. The alkali spreading value (ASV) had limited impact on the taste value of rice, but low-ASV rice is more resistant to cooking. Grain chalkiness played a critical role in maintaining the integrity of freshly cooked rice and instant rice grains after rehydration. In summary, our study provides crucial insights and guidance for rice breeding, with the goal of developing excellent quality and enhancing the processing of instant rice.

It is well known that the overall quality of japonica/geng rice is superior to that of indica/xian rice varieties. However, the molecular mechanisms underlying the quality disparities between these two subspecies of rice are still largely unknown. In this study, we have pinpointed a gene homologous to SLR1, termed LCG1, exhibiting significant expression during early caryopsis development and playing a specific role in regulating rice chalkiness and taste by affecting the accumulation of grain storage components, starch granule structure and chain length distribution of amylopectin. LCG1 physically interacts with OsBP5 and indirectly influences the expression of the amylose synthesis gene Waxy (Wx) by hindering the transcriptional activity of the OsBP5/OsEBP89 complex. Notably, sequence variations in the promoter region of LCG1 result in enhanced transcription in japonica rice accessions. This leads to elevated LCG1 expression in CSSL-LCG1Nip, thereby enhancing rice quality. Our research elucidates the molecular mechanism underlying the impact of the LCG1-OsBP5/OsEBP89-Wx regulatory pathway on rice chalkiness and taste quality, offering new genetic resources for improving the indica rice quality.

As a typical climacteric fruit, tomato (Solanum lycopersicum) is widely used for studying the ripening process. The negative regulation of tomato fruits by transcription factor SlNAC1 has been reported, but its regulatory network was unclear. In the present study, we screened a transcription factor, SlERF109-like, and found it had a stronger relationship with SlNAC1 at the early stage of tomato fruit development through the use of transcriptome data, RT-qPCR, and correlation analysis. We inferred that SlERF109-like could interact with SlNAC1 to become a regulatory complex that co-regulates the tomato fruit ripening process. Results of transient silencing (VIGS) and transient overexpression showed that SlERF109-like and SlNAC1 could regulate chlorophyll degradation-related genes (NYC1, PAO, PPH, SGR1), carotenoids accumulation-related genes (PSY1, PDS, ZDS), ETH-related genes (ACO1, E4, E8), and cell wall metabolism-related genes expression levels (CEL2, EXP, PG, TBG4, XTH5) to inhibit tomato fruit ripening. A dual-luciferase reporter and yeast one-hybrid (Y1H) showed that SlNAC1 could bind to the SlACO1 promoter, but SlERF109-like could not. Furthermore, SlERF109-like could interact with SlNAC1 to increase the transcription for ACO1 by a yeast two-hybrid (Y2H) assay, a luciferase complementation assay, and a dual-luciferase reporter. A correlation analysis showed that SlERF109-like and SlNAC1 were positively correlated with chlorophyll contents, and negatively correlated with carotenoid content and ripening-related genes. Thus, we provide a model in which SlERF109-like could interact with SlNAC1 to become a regulatory complex that negatively regulates the tomato ripening process by inhibiting SlACO1 expression. Our study provided a new regulatory network of tomato fruit ripening and effectively reduced the waste of resources.

Background Two-tiered plant immune responses involve cross-talk among defense-responsive (DR) genes involved in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), effector-triggered immunity (ETI) and effector-triggered susceptibility (ETS). Bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzicola (Xoc) is an important bacterial disease that causes serious threats to rice yield and quality. Transcriptomic profiling provides an effective approach for the comprehensive and large-scale detection of DR genes that participate in the interactions between rice and Xoc. Results In this study, we used RNA-seq to analyze the differentially expressed genes (DEGs) in susceptible rice after inoculation with two naturally pathogenic Xoc strains, a hypervirulent strain, HGA4, and a relatively hypovirulent strain, RS105. First, bacterial growth curve and biomass quantification revealed that differential growth occurred beginning at 1 day post inoculation (dpi) and became more significant at 3 dpi. Additionally, we analyzed the DEGs at 12 h and 3 days post inoculation with two strains, representing the DR genes involved in the PTI and ETI/ETS responses, respectively. Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed on the common DEGs, which included 4380 upregulated and 4019 downregulated genes and 930 upregulated and 1383 downregulated genes identified for the two strains at 12 h post inoculation (hpi) and 3 dpi, respectively. Compared to those at 12 hpi, at 3 dpi the number of common DEGs decreased, while the degree of differential expression was intensified. In addition, more disease-related GO pathways were enriched, and more transcription activator-like effector (TALE) putative target genes were upregulated in plants inoculated with HGA4 than in those inoculated with RS105 at 3 dpi. Then, four DRs were randomly selected for the BLS resistance assay. We found that CDP3.10, LOC_Os11g03820, and OsDSR2 positively regulated rice resistance to Xoc, while OsSPX3 negatively regulated rice resistance. Conclusions By using an enrichment method for RNA-seq, we identified a group of DEGs related to the two stages of response to the Xoc strain, which included four functionally identified DR genes.