Physiology and Molecular Biology of Plants最新文献

Fusarium wilt, caused by Fusarium oxysporum f. sp. fordiis in Vernicia fordii, manifests as severe symptoms that significantly reduce global tung oil yield. However, the molecular-mechanisms of the Vernicia-Fusarium interaction are yet to be fully elucidated. Here, we cloned VfLRR-RLK1 from tung tree roots, which contained 1134 bp, encoding 378 AA. To further analyze VfLRR-RLK1 function in resistance to Fusarium wilt, we obtained stable T4-generation transgenic Arabidopsis thaliana and tung tree VfLRR-RLK1 virus-induced gene silencing (VIGS) RNAi plants. A. thaliana plants overexpressing VfLRR-RLK1 exhibited more robust root development and markedly increased Fusarium wilt disease resistance. In response to Fusarium wilt stress, transgenic A. thaliana exhibited increased catalase (CAT) and superoxide dismutase (SOD) enzyme activities, while showing reduced O₂ ^- and hydrogen peroxide (H₂O₂) accumulation. The findings suggest that VfLRR-RLK1 may diminish plant reactive oxygen species (ROS) levels and foster root development by activating the ROS antioxidant scavenging system during plant Pattern Triggered Immunity responses, enhancing resistance to Fusarium wilt. The study on the function of VfLRR-RLK1 is crucial in breeding programs aimed at developing tung tree resistant to Fusarium wilt, and lays the groundwork for more effective disease management strategies and the cultivation of tung tree varieties with enhanced resistance to this disease.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01512-y.

The current climate change has a profound impact on agricultural production. Despite the unanimous efforts of several nations to prevent further increase in global temperatures, developing adaptive strategies by imparting heat tolerance in crop plants is essential to ensure global food security. This study demonstrates the impact of heat stress on the morphological, physiological and biochemical properties of different groundnut genotypes derived from a recombinant inbred line (RIL) population (JL 24 × 55-437). The plants were grown in controlled conditions and a high-temperature stress of 45 °C was gradually imposed by placing the plants in an environmental chamber during peak reproductive stage [25 days after sowing (DAS) to 60 DAS]. Heat tolerant genotypes had better biochemical machinery to withstand the heat stress-induced oxidative burst with higher activity of catalase and peroxidase. Also, the tolerant genotypes had lesser membrane damage as indicated by lower malondialdehyde levels. Greater expression of heat shock proteins (HSP17) transcripts alongside elevated levels of both enzymatic and non-enzymatic antioxidant activity was observed when exposed to high temperature, indicating their potential association with heat stress tolerance in groundnut.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01520-y.

Yellowing is the first visually observable sign of plant leaf senescence. We found that Arabidopsis double knockout mutant gdh1gdh2 for genes of NAD(H)-dependent glutamate dehydrogenase retains green color of the leaves (stay-green phenotype) during a dark-induced senescence, in contrast to wild-type plants, whose leaves turn yellow. When the gdh1gdh2 plants are exposed to the dark more than four days, they demonstrate slower chlorophyll degradation than in the wild-type plants under the same conditions, as well as dysregulation of chlorophyll breakdown genes encoding chlorophyll b reductase, Mg-dechelatase, pheophytinase and pheophorbide a oxygenase. The slowed degradation of chlorophyll b in gdh1gdh2 plants significantly alters the chlorophyll a/b ratio. Ion leakage in the mutant plants increases significantly from four to eight days in the darkness, correlating with their premature death during this period. The discovered facts suggest a functional connection between activity of NAD(H)-dependent glutamate dehydrogenase and dark-induced senescence progress in Arabidopsis.

Rhamnolipids (RLs) are bioactive compounds that have gained a lot of attention for their potential applications in agriculture. However, the exploration of RLs in passion fruit plants remains limited. This study aimed to investigate the role of RLs in passion fruit plants growth and defense responses. Firstly, the results demonstrated that RLs act as plant growth regulators, significantly enhancing the survival rate and root system development of passion fruit seedlings propagated by cutting. Further analyses suggested that RLs may enhance photosynthetic capacity and modulate the accumulation of indoleacetic acid (IAA) and cytokinin (CTK) in passion fruit cuttings, thereby promoting plant growth and development. Additionally, this study revealed that RLs effectively reduced susceptibility to viral pathogen telosma mosaic virus (TeMV) in passion fruit plants compared to distilled water-pretreated controls, resulting in alleviated disease symptoms. Significant up-regulation of antioxidative enzyme activities and reducing substances were observed in RL's-pretreated plants upon TeMV-inoculation compared to distilled water-pretreated ones. Moreover, RLs were found to promote other defense-related signaling pathways upon TeMV-inoculation in passion fruit plants, including salicylic acid (SA) accumulation and expression levels of defense-related genes such as pathogenesis-related gene (PR3), phenylalanine ammonia-lyase (PAL), transcription factors (TFs) WRKY and NAC. Collectively, these findings underscored the positive roles played by RLs both in promoting growth and eliciting defense responses within passion fruit plants. These results provided valuable insights for designing environment-friendly management strategies for cutting propagation as well as prevention and control measures against viral diseases in passion fruits.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01511-z.

Chinese cabbage (Brassica rapa ssp. pekinensis) is a globally cultivated and consumed leafy vegetable due to its abundant plant secondary metabolites and antioxidant compounds, including flavonoids, ascorbic acids, glucosinolates, and vitamins, which have been reported to confer health-promoting effects. Glucosinolates components in leaves of Chinese cabbage plantlets under different concentrations of sodium selenite (0, 30, and 50 μmol/L) were analyzed. Seven glucosinolates were identified and quantified using UHPLC-QTOF-MS. Finally, treatments with 30 and 50 μmol/L Na₂SeO₃ solution significantly increased the levels of total selenium content as well as total phenols, flavonoids, anthocyanins, and DPPH free radical scavenging ability in Chinese cabbage seedlings. Our results revealed that 30 μmol/L Na₂SeO₃ effectively enhanced aliphatic glucosinolate levels and total glucosinolate content while causing a significant reduction in indole glucosinolates. Furthermore, downregulation was observed for BrCYP79F1, BrBCAT4, and BrMAM1 genes associated with aliphatic glucosinolate synthesis. Conversely, BrMYB28 and BrCYP83A1 genes exhibited significant upregulation. Thus, the positive influence of Na₂SeO₃ on glucosinolate biosynthesis in Chinese cabbage can be attributed to the upregulation of key genes related to this process.

Pyricularia (syn. Magnaporthe) oryzae is responsible for the blast disease in rice resulting in a greater extent of yield loss. However, some of the cultivars of rice have the ability to survive this devastating infection due to the presence of R (resistance) genes. Therefore, genome wide association study (GWAS) was undertaken using a panel of 400 rice landraces (ARC panel) and a set of filtered 38,723 single nucleotide polymorphisms (SNPs). The highest SNPs were mapped to chromosome 1 with a number of 4332 SNPs and lowest (2252) in chromosome 12. The ARC panel was evaluated phenotypically which revealed that 6% of the selected cultivars has resistance to rice blast disease with SES score of 1. The majority of the resistant cultivars belong to the group Asra of the panel. The population structure analysis was executed wherein three genetic subpopulations were identified namely RC1, RC2, RC3 and an admixture population constituting 48 accessions. Further, GWAS detected 15 significant association signal with P value in the range of 1.03E-05 to 1.03E-04, effect ranged from - 1.18 to 1.06, phenotypic variance explained was from 0 to 7.14%, R² of 0.047 to 0.058, and minor allele frequency of 0.107 to 0.444. Eleven (Os01g39980, Os01g56130, Os01g67100, Os01g67110, Os03g41030, Os04g33310, Os07g42104, Os09g06464, Os09g08920, Os09g38800, Os12g37680) out of these 15 significant associations were identified as the candidate loci for the blast resistance in rice that will serve as an important genetic resistance source to be introgressed into an elite rice line in future breeding programs for deciphering blast resistance in rice. The GWAS study presented in this article helped to uncover significant gene regions which encode proteins to resist blast infection in rice plant. This is the first report on the GWAS analysis for blast resistance in unique landraces of rice from Northeast India employing single nucleotide polymorphism.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01518-6.

Small chemical molecules are attractive agents for improving the plant processes associated with plant growth and stress tolerance. Recent advances in chemical biology and structure-assisted drug discovery approaches have opened up new avenues in plant biology to discover new drug-like molecules to improve plant processes for sustained food production. Several compounds targeting phytohormone biosynthesis or signalling cascades were designed to alter plant physiological mechanisms. Altering Abscisic acid synthesis and its signalling process can improve drought tolerance, and the processes targeted are reversible. Molecules targeting cytokinin, Auxin, and gibberellic acid regulate plant physiological processes and can potentially improve plant growth, biomass and productivity. The potential of molecules may be exploited as agrochemicals to enhance agricultural productivity. The discovery of small molecules provides new avenues to improve crop production in changing climatic conditions and the nutritional quality of foods. We present the rational combinations of small molecules with inhibitory and co-stimulatory effects and discuss future opportunities in this field.

Understanding how maize responds to temperature stress is crucial for improving its resilience and productivity under changing climate conditions. Previous studies have shown that exogenous allantoin (ALA) regulates various physiological processes in plants under cadmium and salinity stress. The existing body of literature provides limited insight into the specific mechanisms that govern the impact of ALA on the physiological and biochemical responses of maize plants under heat stress. This study aims to investigate the role of ALA in regulating oxidative defense, secondary metabolism, and ion homeostasis in maize under heat stress, with the ultimate goal of improving maize resilience and productivity. The current investigation displayed visible depression in growth, chlorophyll content, and nutrient uptake in maize cultivars (tolerant cv. Pearl and sensitive cv. Pak-afgoi) under heat stress. Heat stress raised MDA and H₂O₂ levels in plants, indicating hampered ROS detoxification that might have impeded nutrient acquisition in plants more profoundly in heat-sensitive cv. Pak afgoi. ALA (150 and 300 mg L^-1) promoted plant heat stress tolerance. ALA (300 mg L^-1) increased enzymatic antioxidant activities and antioxidant molecule buildup, which diminished cell ROS levels. ALA increased osmolyte accumulation, raised chlorophyll and nutrient uptake, and mitigated oxidative damage in maize under heat stress. After 72 h of recovery from heat stress, ALA significantly enhanced biomass, photosynthetic pigments, ROS detoxification, and nutrient uptake while minimizing oxidative damage, aiding rapid plant recovery from heat stress.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01519-5.

This study explores the Laccase gene (AaLac) family along with AaLac1 expression in hairy roots of A. annua. 42 AaLacs were identified by detecting three conserved domains: Cu-oxidase, Cu oxidase-2, and Cu oxidase-3. The physicochemical properties show that AaLacs are proteins with 541-1075 amino acids. These proteins are stable, with an instability index less than 40. Phylogenetic and motif studies have shown structural variants in AaLacs, suggesting functional divergence. 22 AaLac cis-regulatory elements were selected for their roles in drought stress, metabolic modulations, defense, and stress responses. A comparison of AtLac and AaLac proteins showed that 11 AtLacs mitigates stress reactions. In silico expression, analysis of 11 AtLacs showed that AtLac84 may function under osmotic stress. Thus, the Homolog AaLac1 was selected by expression profiling. The real-time PCR results showed that AaLac1 enhances osmotic stress tolerance in shoot and root samples. It was also used to analyze AaLac1, ADS, and CYP71AV1 gene expression in hairy roots via induction. The transformed hairy roots exhibited a greater capacity for PEG-induced osmotic stress tolerance in contrast to the untransformed roots. The gene expression analysis also depicted a significant increment in expression of AaLac1, ADS, and CYP71AV1 genes to 3.8, 6.9, and 3.1 folds respectively. The transformed hairy roots exhibited a significant increase of 2.2 and 1.4 fold in flavonoid and phenolic content respectively. Also, lignin content and artemisinin content increased by 7.05 folds and 95.6% with respect to the control. Thus, transformed hairy roots of A. annua under PEG-induced osmotic stress demonstrate the involvement of the AaLac1 gene in stress responses, lignin biosynthesis, and secondary metabolism production.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01516-8.

High salinity is an abiotic stress that limits crop production. Kenaf (Hibiscus cannabinus L.) is an annual fiber crop of the genus Hibiscus in the family Malvaceae with a certain tolerance to salt stress. Seed priming has been shown to ameliorate the adverse effects of salt stress on plants. However, the salt resistance mechanism in kenaf seeds treated with priming agents is not fully understood. In this study, we used four priming agents (H₂O, PEG, ABA, KNO₃) in different concentrations to treat kenaf seeds, and subjected the induced kenaf seedlings to salt stress (150 mM NaCl) to measure their agronomic traits and physiological and biochemical indicators. Our results indicate that the optimal priming concentration for PEG was 10%, 0.5 μM for ABA, and 0.5% for KNO₃. Under these treatment concentrations, the germination rate of kenaf was significantly increased, and the fresh weight was also increased by 35.1%, 33.39%, 20.78% and 15.3%, respectively. Furthermore, the use of priming agents can alleviate the adverse effects of salt stress to a certain extent, significantly increase the agronomic indicators such as plant height, stem thickness, and leaf area of kenaf, enhance the ability of plants to perform photosynthesis, further improve the activity of antioxidant enzymes and increase the content of osmotic material, and reduce the accumulation of cell H₂O₂, O₂ ^- and MDA. Meanwhile, seed priming can also enhance the expression of HcSOS1, HcNHX, HcHKT, HcCBL, HcCIPK, HcPD and HcNCED involved in the salt stress pathway. These results warrant that seed priming can reduce the adverse effects of salt stress on kenaf.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01521-x.