Plant Physiology and Biochemistry最新文献

Infections caused by root-knot nematodes (RKNs) significantly impair vegetable growth and crop yield, posing a severe threat to global food security. Our previous study indicated that fungal-derived 2-furoic acid was a promising lead compound for the exploitation of eco-friendly nematicides. However, the exact molecular mechanism remains poorly understood. In this study, we observed behavioral changes in the nematodes following treatment with 100 μg/mL of 2-furoic acid. Subsequently, transcriptomics and metabolomics were combined to identify changes in differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs). Transcriptome analysis revealed 199 up-regulated and 109 down-regulated DEGs. Metabolomics analysis indicated that 140 metabolites (72 up-regulated and 68 down-regulated) exhibited significant differences. Notably, the integrated transcriptomics and metabolomics analysis identified a total of 72 DEGs and 54 DEMs annotated across 51 pathways, including lipid metabolism and amino acid metabolism. Intriguingly, 14 out of the 51 pathways were simultaneously annotated to the downregulated calmodulin gene (cam). RNA interference (RNAi) results demonstrated that the down-regulated cam, a potential drug target for controlling RKNs, significantly reduced the motility, infectivity, and pathogenicity of M. incognita. Our results provide insights into the molecular basis of 2-furoic acid against M. incognita and offer a valuable theoretical foundation for the design of eco-friendly nematicides.

Thioredoxin is a multifunctional acidic protein widely presented in organisms that regulates intracellular redox processes, participating in a series of biochemical reactions in cells to affect the growth and development of plants. Although the thioredoxin (TRX) gene family has been widespread recognized across various plant species, and the tomato genome has been sequenced for years now, of tomato (Solanum lycopersicum) has remained largely uncharted in terms of identifying and unraveling the functional intricacies of is TRX genes. In this study, 53 SlTRX genes were identified, unevenly distributed across 11 of the 12 tomato chromosomes. These 53 SlTRX genes were categorized into 4 distinct subfamilies based on their evolutionary kinship and phylogenetic development. Expression profiling reveals that most of SlTRX genes exhibited distinct expression patterns across various tissues and developmental stages. In addition, the gene structure, conserved protein motifs and cis-elements of 53 SlTRX genes were analyzed simultaneously. In our rigorous in silico expression analysis, 8 SlTRX genes were meticulously selected for subsequent experiments. Subcellular localization indicated that these 8 SlTRX genes were localized in chloroplasts. Furthermore, these 8 SlTRX genes were responsive to abiotic stress (salt, drought and cold stress) under the qRT-PCR analysis, and their different expression patterns under diverse types of treatments indicated their possible roles in stress tolerance in tomato. Based on these results, SlTRX2, whose expression level continued to increase under salt stress, was selected for silencing to further investigate its function, and furthermore, silencing SlTRX2 inhibited plant growth and led to a significant reduction in photosynthesis under salt stress. Yeast two-hybrid and luciferase complementation imaging assays demonstrated that SlTRX2 may regulate tomato salt resistance by affecting related photosynthetic genes. Thus, our study establishes a valuable resource for further analysis on biological functions of SlTRX genes and will provide important insights in the mechanism of action under stress.

In order to investigate the impact of hot air (HA) treatment on the sugars and volatiles in postharvest nectarine fruit, nectarines were treated with HA at 40 °C for 4 h and stored at 1 °C for 35 days. Changes of sugars, free and glycosidically bound volatiles, β-glucosidase (β-Glu) activity, and the gene expression of UGT (UDP-glucosyltransferase) in nectarine fruit were determined. The results showed that compared with CK, HA treatment delayed the firmness decline of 48.01%, weight loss of 32.13%, internal browning index of 58.03%, and maintained the high commodity quality of nectarine fruit at the end of storage. HA could reduce the content of aldehydes and increase the content of esters. The bound linalool in HA increased by 171.41% compared with the CK. In addition, the results of in vitro experiments showed that glucose and sucrose systems could increase the content of free and bound linalool by up-regulating the expression of PpUGT85A2, promoted the accumulation of bound benzaldehyde and nonanal, and reduced the corresponding free volatile compounds, it showed that free aldehydes can be synthesized from soluble sugars into bound aldehydes.

In some peanut (Arachis hypogaea L.) producing regions, growth and photosynthesis-limiting low and high temperature extremes are common. Heat acclimation potential of photosynthesis and respiration is a coping mechanism that is species-dependent and should be further explored for peanut. The objectives of the current study are (1) to evaluate the response of photosynthesis, its component processes, and respiration to low and high temperatures, and (2) to determine the heat acclimation potential of photosynthesis and respiration during early vegetative growth of peanut. Peanut was exposed to four different growth temperature regimes: (1) optimum temperature (30/20 °C day/night), (2) low temperature (20/15 °C), (3) moderately high temperature (35/25 °C), and (4) a high temperature extreme (40/30 °C). Low temperature and both high temperatures caused substantial reductions in growth and net photosynthetic rate. Mesophyll conductance and RuBP regeneration co-limited net photosynthetic rate under low temperature. Rubisco carboxylation was the most negatively impacted biochemical processes by high temperatures; however, diffusional limitations were not evident under high temperature conditions. Photosynthesis did not acclimate to high temperatures, while respiration and photorespiration exhibited heat acclimation. The inability of photosynthesis to acclimate to high temperature is likely a major constraint to early season growth in peanut.

The pigments present in the fibers of naturally colored cotton provide excellent antibacterial and environmentally friendly properties, making these colored fibers increasingly favored by the textile industry and consumers. Proanthocyanidins (PAs), the critical pigments responsible for the color of brown cotton fiber, are produced on the endoplasmic reticulum and subsequently transported to the vacuole for polymerization and/or storage. Previous studies have identified GhTT12 as a potential transmembrane transporter of PAs in Gossypium hirsutum, with GhTT12 being a homolog of Arabidopsis Transparent Testa 12 (TT12). Here, we analyzed the spatiotemporal expression pattern of GhTT12, silenced and transiently overexpressed GhTT12 in cotton to confirm its biological function. The GhTT12 protein contains two Multidrug and toxic compound extrusion (MATE) domains and 12 transmembrane helices, and the GhTT12 gene displayed predominant expressions in flowers and fibers of cotton that had higher contents of PAs, particularly in brown cotton, suggesting that GhTT12 may play a role in the transport of PAs in cotton. Silencing or transient overexpression of GhTT12 in cotton resulted in decreased or increased accumulation levels of PAs and anthocyanins (Ans), respectively, accompanied by correspondingly down- or up-regulation of genes involved in PAs synthesis (GhANR) and oxidative polymerization (GhTT10). These findings indicate that GhTT12 may also participate in the biosynthesis of PAs and Ans. Moreover, the silencing of GhTT12 led to a lightening of the color of brown cotton fibers, probably due to the reductions in both PAs content and PAs oxidation. Overall, this study, along with previous research, provides compelling evidence to support the hypothesis that GhTT12 transports PAs and Ans while also regulating their biosynthesis and oxidative polymerization, thereby promoting the accumulation of PAs and Ans in cotton and ultimately affecting the fiber coloration.

To investigate the effect of combined action of discharge plasma (DP) and plasma-activated water (PAW) in mutagenesis breeding, this study focuses on Agropyron mongolicum. We utilized high-voltage DC pulsed dielectric barrier discharge for seed treatment, alone and in combination with PAW. The research focused on germination rates, evolution of physicochemical properties of imbibition residual solution, reactive oxygen species (ROS), malondialdehyde (MDA), and volatile organic compounds (VOCs) to assess DP-induced damage and variability in Agropyron mongolicum. Results indicated that after 18 h of combined treatment, the germination rate of Agropyron mongolicum dropped to 29.67%, below the LD50 threshold. Treated seedlings exhibited elevated ROS and MDA levels compared to controls. The concentration of reactive nitrogen and oxygen species (RONS) in the imbibition residual solution of the combined treatment group was lower than in freshly prepared PAW, indicating RONS penetration into the seed embryo via water, leading to oxidative damage. Enhanced lateral root differentiation, early tillering, increased biomass, and albino variant plants were observed in the surviving seedlings post-treatment. Transmission electron microscope (TEM) and Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) analysis confirmed that plasma treatment induced oxidative damage in Agropyron mongolicum. In conclusion, high-power, long-duration direct DP treatment caused oxidative damage and reduced germination rates in Agropyron mongolicum, with PAW intensifying these effects. PAW was identified as the main driver of variation and lethality, while DP played a supportive role. Combined DP and PAW treatment induced variations in Agropyron mongolicum, providing experimental evidence and theoretical insights for applying DP treatment in plant mutagenesis breeding.

Melatonin (MT) serves as a potent antioxidant in plant organisms, bolstering their resilience to temperature stress. In this study, the impact of MT on various buckwheat varieties under high-temperature stress conditions (40 °C) was investigated. Specifically, five buckwheat seedling varieties, comprising three sweet buckwheat variants (Fagopyrum esculentum) and two bitter buckwheat types (Fagopyrum tataricum), were subjected to foliar sprays of melatonin at concentrations of 50, 100 and 200 μM, with water at 25 °C employed as a control. Results demonstrated that exogenous MT at different concentrations improved the growth and physiological parameters of buckwheats, ameliorating damage induced by high-temperature stress. Notably, the application of 100 μM MT significantly augmented shoot biomasses of buckwheat seedlings under high-temperature conditions. Furthermore, the MT significantly increased the levels of osmotic adjustment substances and chlorophyll concentrations, enhanced antioxidant enzyme activities, chlorophyll fluorescence parameters, and improved photosynthetic gas exchange parameters in five different varieties of buckwheat. This led to the alleviation of damage to buckwheat seedlings subjected to high-temperature stress. Subsequently, five advanced statistical analysis methods: Principal Component Analysis, Grey Relational Analysis, Path Coefficient Analysis, Membership Function Method, and Coupling Coordination Analysis were employed to delve deeper into the existing data indicators. To summarize, the beneficial effect of exogenous melatonin on seedling growth is primarily achieved through the coordination and regulation of the antioxidant enzyme system and osmotic regulatory substances, ensuring the growth and development of buckwheat seedlings while also improving their heat tolerance. The treatment with a concentration of 100 μM of MT was the most effective.

Alkaline salts have more severe adverse effects on plant growth and development than neutral salts do. However, the adaptive mechanisms of plants to alkaline salt stress remain poorly understood, especially at the molecular level. The Songnen Plain in northeast China is composed of typical 'soda' saline-alkali soil, with NaHCO₃ and Na₂CO₃ as the predominant alkaline salts (pH ≥ 9.2). Leymus chinensis can grow on this saline-alkali land, showing strong adaptability. We investigated the role of succinic acid and genes regulating its synthesis in the response to alkaline salt stress in L. chinensis roots. Compared to the neutral salt (NaCl) and high pH treatments, the alkaline salt (NaHCO₃ and Na₂CO₃) treatment specifically caused changes in 11 organic acids, of which the increase in succinic acid was the greatest. The exogenous addition of succinic acid alleviates the damage of alkaline salt to L. chinensis roots. Further, two genes encoding succinyl-coenzyme A ligase (SUCLA) subunits that regulate succinic acid synthesis, LcSUCLAα and LcSUCLAβ, were identified; these genes interact and were localized within mitochondria. Overexpression of LcSUCLAα and LcSUCLAβ caused an increase in succinic acid and enhanced tolerance of NaHCO₃ in transgenic rice seedlings. These results suggest that LcSUCLAα and LcSUCLAβ may be involved in the response to alkaline salt stress through the regulation of succinic acid synthesis.

In this research, we sought to investigate how high temperature, salinity, and CO₂ affect endogenous phytohormones, photosynthesis, and redox homeostasis in Caragana korshinskii Kom (C. korshinskii) leaves, as well as to comprehensively evaluate the plant's physiological response to multiple environmental stressors. The elevated temperature (e[T]), elevated Na⁺ (e[Na]), and elevated temperature and Na⁺ (e[T-Na]) treatments increased abscisic acid (ABA) and reduced zeatin-riboside (ZR), indole-3-acetic acid (IAA), and gibberellic acid (GA₃). These changes induced stomatal closure, and the subsequent reduction in photosynthetic rate triggered the generation of superoxide anion (O₂^·-) and hydrogen peroxide (H₂O₂). In response, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity increased, and free proline and total soluble sugars were accumulated. However, membrane lipid peroxidation was still aggravated. Under elevated CO₂ (e[CO₂]), the dramatic hormonal fluctuations and photosynthetic inhibition resulting from e[T], e[Na], and e[T-Na] were alleviated. Moreover, e[CO₂] reduced ROS generation caused by e[T], e[Na], and e[T-Na], and stabilized antioxidant enzyme activities and non-enzymatic compound concentrations. Compared with e[T], e[Na], and e[T-Na], the increased malondialdehyde (MDA) content was effectively alleviated under elevated CO₂ and temperature (e[CO₂-T]), elevated CO₂ and Na⁺ (e[CO₂-Na]), and elevated CO₂, temperature, and Na⁺ (e[CO₂-T-Na]). Overall, our research suggest that e[CO₂] may alleviate the negative impacts of e[T] and e[Na] on plant physiology.

Selenium nanoparticles are well known for their antioxidant and stress-mitigating properties. In our study, composite nanoformulations of selenium and chitosan have been synthesized. The synthesized composite nanoformulations were 50 nm in diameter, spherical in shape, and had higher antioxidant activities and stability than the selenium and chitosan nanoparticles. In our study, Luit rice seedlings grown in an arsenic-treated Hoagland solution showed a reduction of growth, decreased superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, ascorbate, and glutathione content. Otherwise, superoxide anion, hydrogen peroxide, and malondialdehyde content increased in arsenic-stressed conditions. The alone application of Selenium nanoparticles, chitosan nanoparticles, and their nanoformulation improved growth, reduced stress parameters, and enhanced enzymatic and non-enzymatic activity. Additionally, the reduction of superoxide anion, hydrogen peroxide, and malondialdehyde content was higher by applying composite nanoformulations in arsenic-stressed conditions than selenium and chitosan nanoparticles. The treatment of composite nanoformulation also regulated the enzymatic and non-enzymatic antioxidant activity higher than that of other nanoparticles. It might be due to the higher stability and antioxidant activity of composite nanoformulations than that of selenium and chitosan nanoparticles. Our study suggests that the composite nanoformulation enhanced the growth of rice plants by mitigating arsenic-induced reactive oxygen species and upregulating antioxidant activity.